Source: AGRICULTURAL RESEARCH SERVICE submitted to
INTEGRATED ORCHARD MANAGEMENT FOR DECIDUOUS TREE FRUIT CROPS
Sponsoring Institution
Agricultural Research Service/USDA
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0402356
Grant No.
(N/A)
Project No.
1931-21220-011-00D
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Dec 15, 1998
Project End Date
Dec 14, 2003
Grant Year
(N/A)
Project Director
GLENN D M
Recipient Organization
AGRICULTURAL RESEARCH SERVICE
2217 WILTSHIRE ROAD
KEARNEYSVILLE,WV 25430
Performing Department
(N/A)
Non Technical Summary
(N/A)
Animal Health Component
(N/A)
Research Effort Categories
Basic
40%
Applied
60%
Developmental
0%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2031110102015%
2031114102020%
2111110113020%
2111115113010%
2111211102010%
2131110102015%
2131114102010%
Goals / Objectives
Develop pest management technologies that reduce the dependence on conventional synthetic pesticides by integrating new biocontrol and alternative insect control programs into the tree fruit production systems. Develop knowledge and strategies to improve nutrient and water use efficiencies of production systems. Characterize the physiological basis of environmental and genotypic interactions for fruit bud initiation and root plasticity. Develop systems that integrate traditional management of the tree and soil with novel techniques to manage fruit, shoot and root growth and minimize pest damage.
Project Methods
Orchard management practices will be altered to increase biological and bio-based control of pests and ensure sustainable production. Particle film and other developing technologies will be incorporated into production system to reduce the use of synthetic pesticides and mitigate the effects of environmental stresses. Natural products will be evaluated for pest control. Establish an insect rearing facility for natural and beneficial insect predators. Develop means of dispersing beneficial insects. Different green and organic mulches will enhance the habitat for predatory and parasitic arthropods, manage weeds, modify root growth and distribution, and improve nutrient and water use efficiency, and fruit quality. Sod, shading, and reflective ground covers will be used to regulate carbon allocation to fruit bud development. Root distribution and morphology, phytohormone levels, and response to competition will be measured in apple and peach cultivars. Carbon allocation will be modeled in fruit bud and root tissues.

Progress 12/15/98 to 12/14/03

Outputs
1. What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter? This project is terminated and this is the final report for this project. A new project plan was reviewed and approved under the OSQR process as project 1931-21220-015-OOD, Integrated Orchard Management for Deciduous Tree Fruit Crops. The national tree fruit industry is facing the loss of key insecticides by FQPA (Food Quality Protection Act), in addition to continual development of insect resistance to insecticides. The presence of agrochemicals in drinking water and waterways demonstrates the need to efficiently manage nutrients, water, and the application of agrichemicals. Concerns for human health and the environment have led to reduced pesticide and fertilizer use through the development of alternative pest and fertilizer practices in orchard management systems; however, these practices need to be integrated to maintain high orchard productivity and economic sustainability. Reduction in the use of pesticides is a national priority. Pesticide application and pruning account for over 50% of the cost of fruit production in the eastern U.S. where conditions favor vegetative growth and heavy pest pressure. The loss of key insecticides in 2004 limits grower ability to control insect pests and increases the risk of significant fruit loss and increases the cost of production. More efficient cultural management practices which integrate the soil and climatic conditions of the region into the production system will improve production efficiency, lower pesticide use and production costs, and increase competitiveness and profitability to fruit growers. Without continued improvement in cultural management practices, tree fruit growers throughout the eastern U.S. will cease to be competitive in a global market and the industry will be lost to foreign imports. The research project has six multidisciplinary objectives: 1) the ecology of insects involved in biological control, including insect behavior, 2) new methods of monitoring key insect pests in order to effectively manage and reduce pesticide usage, 3) the mechanisms of insect control with particle films, sugar esters and other materials for insect control, 4) the role of heat, water and nutrient stress in plant productivity and fruit quality, 5) the mechanism of vegetative growth control and inducing fruit buds, and 6) the role of training and orchard floor management methods to affect light and temperature within the canopy. The research program falls under National Program 304 (30%), Crop Protection and Quarantine and NP 305 (70%), Crop Production, and addresses goals 1 and 3 of the National Program Action Plan. Specifically these are: GOAL 1: Enhance economic opportunities for agricultural producers. Objective 1.1: Provide the Science-Based Knowledge and Technologies to Generate New or Improved High Quality, Value-Added Products and Processes To Expand Domestic and Foreign Markets for Agricultural Commodities; 1.1. 2: Provide higher quality, healthy foods that satisfy consumer needs in the United States and abroad; Objective 1.2: Contribute to the Efficiency of Agricultural Production Systems; 1.2.5: Provide producers with scientific information and technology that increase production efficiency, safeguard the environment, and reduce production risks and product losses; 1.2.6: Improve the understanding of the biological mechanisms that influence plant growth, product quality, and marketability to enhance the competitive advantage of agricultural commodities. GOAL 3: Enhance protection and safety of the Nation's agriculture and food supply. Objective 3.2: Develop and Deliver Science-Based Information and Technologies to Reduce the Number and Severity of Agricultural Pest, Insect, Weed, and Disease Outbreaks and 3.2.5, Provide fundamental and applied scientific information and technology to protect agriculturally important plants from pests and diseases. This research results in new methodologies that will reduce chemical and mineral release from agricultural activities, the environmental impact of tree fruit production and pesticide residues on food products, while providing improved fruit quality for the consumer and sustainable tools for growers. The results will provide new knowledge, methods and economic information for crop production in traditional, small farm, and organic farming systems allowing for a more sustainable U.S. agriculture. Alternative insect control products have been developed, such as the particle film, Surround, and sugar esters. New methods of orchard management enhance biological control of orchard pests, improve fruit quality and yield, reduce weed competition, and reduce the amount of pesticides and fertilizers applied in the orchard system. The incorporation of plant bioregulators into orchard systems reduces excess vegetative growth and habitat for insect pests while increasing spray efficiency and so reduces the amount of pesticides needed to control a pest. 2. List the milestones (indicators of progress) from your Project Plan. This project is terminated and this is the final report for this project. A new project plan was reviewed and approved under the OSQR process as project 1931-21220-015-OOD, Integrated Orchard Management for Deciduous Tree Fruit Crops. The milestones for the project were: FY2000. Compositional changes in particle films and sugar esters will be synthesized and initial efficacy evaluations performed. Determine whether purple tansy is a good addition to the ground cover mix or if it contributes to plant bug damage, and if a problem, remove it from the system. Evaluate the contribution of ground covers and tree species to insect control. Identify the key predators that are enhanced by use of composted chicken manure; evaluate the potential for E. coli growth on compost (if positive, discontinue study). Refine trap design for plum curculio monitoring. Initiate N sampling in soil and plants and evaluate horticultural effects. Collect weed abundance data. Forecast , environmental, and plant data will be collected and initial algorithms prepared for Maryblyt, bloom and maturity models. Field trials to evaluate pH adjuvants in particle films and PGR effects on fireblight will be established. Evaluate effective rates and timing of PGR applications. Establish trials to determine if irrigation and nutrient management treatments are reducing the impact of ground covers on yield and quality. Establish root restriction studies and collect initial data on phytohormone and nitrogen movement. Whole tree canopy photosynthesis chambers will be built and monthly sampling completed for particle film treatments with two crop loads. Evaluate water use efficiency. Growth chamber and field studies on return bloom initiated. Mineral nutrition studies are initiated. Identify plastic reflective groundcover materials that enhance red color in selected apple cultivars when applied to the orchard floor at least six weeks before harvest. Peach growth type study established and data collected on root and shoot architectural relationships. FY 2001. Develop new knowledge to support registration of sugar ester material for insect control in a wide range of crops. Develop new knowledge to support registration of particle film materials with disease control in tree fruit crops. A particle delivery system will be developed that improves the efficiency of current agrochemicals and reduces use rates. Evaluation of 17 new apple cultivars will be completed. FY 2002. Develop new knowledge to support registration of sugar ester material for insect control in a wide range of crops and particle film materials with disease control in tree fruit crops. A particle delivery system will be developed that improves the efficiency of current agrochemicals and reduces pesticide use rates. Complete the evaluation of 22 new apple cultivars. Establish grower demonstration apple and peach orchards using organic production protocols incorporating flowering plants, composted manure, interplanting peach and apple, and reduced use of insecticides. Initiate a study to evaluate different placement of flowering plants in the orchard to maximize biological control and minimize impact on yield. Develop new information on the use of prohexadione-calcium in hard water and in young apple trees to reduce the incidence of fire blight without adverse effects on shoot growth needed for young trees. Initiate new weed control studies that comply with USDA Organic Standards. Complete assessment of new attractants for plum curculio based on preferences observed for different stone and pome fruit in the field and develop behaviorally based trapping devices. FY 2003. Data collection is completed on the effectiveness of an insect predator complex to control rosy apple aphid. A decision can be made whether the level of biological control is as stable and cost effective as the use of conventional insecticides. This information will be transferred to extension pest management professionals for implementation. Field evaluations are completed on the use of light-reflecting particle film materials as herbicides. The reliability of weed control and the amount of light reflected in the plant canopy are assessed and this information is used by the CRADA partner (Engelhard Corp.) to make a decision to commercialize a formulation. If commercialized, the weed control product will meet National Organic Standards. The key sugar ester chemistries with insecticidal activity and polyol ester blends that are most effective in insect mortality are identified. This information will assist the CRADA partner (AVA Chemical) in determining which chemistries should be focused upon for further field testing, commercialization, and registration as an insecticide. In addition, the information gained from this CRADA will provide a basis for identifying new areas of sugar ester chemistry to pursue. Data collection will be completed how different formulation additives affect the durability, insect control efficacy, and horticultural aspects of kaolin-based particle films. This information will be used by the CRADA partner to determine if significant formulation changes are needed and can result in new particle film products for high rainfall or windy areas of U.S. FY 2004. Effectiveness of flowering plants as a trap crop for attracting stink bugs out of apple orchards as a control of fruit damage will be completed. If economically effective, protocols will be developed for fruit growers. Test experimental lures in experimental orchards for plum curculio based on identification of headspace volatiles from plum trees and test for dogwood borer in commercial orchards based on correct pheromone identification. Field evaluations are completed on the use of light-reflecting particle film materials as herbicides. The reliability of weed control and the amount of light reflected in the plant canopy are assessed and this information is used by the CRADA partner (Engelhard Corp.) to make a decision to commercialize a formulation. If commercialized, the weed control product will likely meet National Organic Standards. Design and conduct studies to confirm preliminary results on the use of plant growth regulators to control the flesh cracking disorder in 'GoldRush' apple. Provide growth and carbon partitioning data sets to collaborator for testing in the Apple Carbon Model. Report on the early performance of novel peach tree growth habits. Characterize how particle film structure changes when formulation components are changed. Characterize physical characteristics of surface active materials. Study the mechanisms of action of particle film and surface active materials on insects and plant physiology. The renewal of the CRADAs with AVA Chemical Ventures and Engelhard Corporation will be pursued to develop new chemistries or new uses. Complete morphological characterization of selected peach growth habits in field and proceed with determination of auxin and cytokinin profiles in these growth habits to establish baseline relationships of hormones and shoot morphology. Develop new information on the effect of potassium nutrition on fruit size of apple. Conditions under which improvements in fruit size are expected will be evaluated (fruit set, potassium status at different times after flowering). 3. Milestones: QUESTION 3A: Milestones that were scheduled to be addressed in FY 2004. How many milestones did you fully or substantially meet in FY 2004 and indicate which ones were not fully or substantially met, briefly explain why not, and your plans to do so. This project is terminated and this is the final report for this project. A new project plan was reviewed and approved under the OSQR process as project 1931-21220-015-OOD, Integrated Orchard Management for Deciduous Tree Fruit Crops. The milestones listed below were scheduled for FY2004. All milestones were substantially met. FY2004. Effectiveness of flowering plants as a trap crop for attracting stink bugs out of apple orchards as a control of fruit damage will be completed. If economically effective, protocols will be developed for fruit growers. Test experimental lures for plum curculio based on identification of headspace volatiles from plum trees in experimental orchards and for dogwood borer based on correct pheromone identification in commercial orchards. Field evaluations are completed on the use of light-reflecting particle film materials as herbicides. The reliability of weed control and the amount of light reflected in the plant canopy are assessed and this information is used by the CRADA partner (Engelhard Corp.) to make a decision to commercialize a formulation. If commercialized, the weed control product will likely meet National Organic Standards. Design and conduct studies to confirm preliminary results on the use of plant growth regulators to control the flesh cracking disorder in 'GoldRush' apple. Provide growth and carbon partitioning data sets to collaborator for testing in the Apple C Model. Report on the early performance of novel peach tree growth habits. Characterize how particle film structure changes when formulation components are changed. Characterize physical characteristics of surface active materials. Study the mechanisms of action of particle film and surface active materials on insects and plant physiology. The renewal of the CRADAs with AVA Chemical Ventures and Engelhard Corporation. will be pursued to develop new chemistries or new uses. Complete morphological characterization of selected peach growth habits in field and proceed with determination of auxin and cytokinin profiles in these growth habits to establish baseline relationships of hormones and shoot morphology. Develop new information on the effect of potassium nutrition on fruit size of apple. Conditions under which improvements in fruit size are expected will be evaluated (fruit set, potassium status at different times after flowering). QUESTION 3B. Milestones that you expect to address over the next 3 years (FY 2005, 2006, & 2007). What do you expect to accomplish, year by year, over the next 3 years under each milestone? This project is terminated. A new project plan was reviewed and approved under the OSQR process as project 1931-21220-015-OOD, Integrated Orchard Management for Deciduous Tree Fruit Crops. The milestones for the new project plan are: FY 2005. Determine the extent that cultural practices and genotypes can (a) increase carbon partitioning to fruit in order to improve fruit quality and (b) reduce pest damage. Collect data and samples for carbohydrate analysis from current diurnal shade treatments. Establish new planting to test supplemental light on apple productivity. Apply low rate PGR treatments to young apple trees to alter growth. Apply fruit thinning treatments and collect carbon partitioning data from apple trees. Evaluate Cornell Carbon model performance and develop new hypotheses if necessary. Collect yield, pruning, canopy light, and fruit quality data from test planting of novel peach growth habits. Determine principle cytokinins in Pillar and Standard peach tree growth habits in the field. Develop root pressure system and secure reliable source of rootstock material for the greenhouse studies of hormone flux in apple. Prepare manuscript on quality of cultivars planted in 1995, summarizing reports from all project sites. Prepare manuscript on cultivar susceptibility to stinkbug damage. Develop arthropod pest management systems and techniques that will reduce costs and environmental impact. Complete analysis of the role of naturally occurring predators on spirea and rosy apple aphid populations to determine if they provide adequate control or need enhancement through conservations practices or augmentation. Identify attractive olfactory and/or visual stimuli for plum curculio and stinkbug. Identify attractive female-produced sex pheromone components for male dogwood borer. Develop and characterize divergent particle films and study mechanisms of action against arthropods. Study modes-of-action of sugar ester in comparison to other surface active compounds. Develop production systems that mitigate nutrient and water stress and pest damage on fruit quality. Establish field plots of subsurface irrigation and novel pest/weed control practices Conduct rate and timing studies with small plots for novel weed control materials. Establish field plots and measure initial soil parameters to measure apple tree response to compost rates. FY 2006. Determine the extent that cultural practices and genotypes can (a) increase carbon partitioning to fruit in order to improve fruit quality and (b) reduce pest damage. Provide validation data sets on growth and carbon partitioning to collaborator for testing in the Cornell Carbon model. Summarize whole-tree PN data as affected by fruit thinners and validate Cornell Carbon model and develop new hypothesis if necessary. Publish initial findings of pruning methods for novel peach growth habits. Establish new planting to determine the effect of rootstock and N fertilization on growth of pillar trees. Identify most promising apple cultivars in the 1999 planting and establish plantings of two most promising cultivars with at least 50 trees. Determine hormone concentrations in wood and bark in internodes of current year peach stems. Determine auxin concentrations in scion, rootstock stem, and rootstock roots of dwarf and invigorating apple clones. Develop arthropod pest management systems and techniques that will reduce costs and environmental impact. Complete analyses of the effect of distance from flower or nectar source at which natural enemies are affected by enhanced food resources and the effect of flower resources on damage to fruit by stink bugs and plant bugs to decide if the flowers increase, decrease, or have no effect on this damage. Develop novel experimental lures and trap designs based on attractive olfactory and visual stimuli, respectively. Develop novel pheromone lures based on responses by male dogwood borer. Complete particle film mechanisms of action for insect control. Develop production systems that mitigate nutrient and water stress and pest damage on fruit quality. Collect water use, growth and pest damage data from subsurface irrigation study. Determine effective rates and timings of weed control materials from small plots and apply these treatments in large plots with young and mature trees to evaluate competition. Measure yield and leaf nutrient content from trees in compost rate study. Measure soil water nitrate content in compost rate study. FY 2007. Determine the extent that cultural practices and genotypes can (a) increase carbon partitioning to fruit in order to improve fruit quality and (b) reduce pest damage. Evaluate growth and carbon assimilation response to supplemental light. Subject additional shade effect data sets to model analysis in order to validate model. Complete evaluation of cultivars in the 1995 planting, remove trees and publish findings. Establish seasonal patterns in auxin and cytokinin of Pillar and Standard peach. Determine auxin concentrations in apple stem segments and cytokinin flux in xylem exudate to establish cytokinin/auxin ratios. Develop arthropod pest management systems and techniques that will reduce costs and environmental impact. Complete laboratory and field studies on the effect of flower and nectar sources on foraging abilities of natural enemies and whether natural enemies move randomly through the orchard or forage along tree rows. Assess potential behaviorally based monitoring technology for plum curculio and stinkbug in experimental and commercial orchards. Assess attractive pheromone lures in conjunction with novel trap designs based on attractive visual cues. Field test new formulations of particle film materials against orchard pests. Develop production systems that mitigate nutrient and water stress and pest damage on fruit quality. Collect initial yield, water use, and pest damage data from field study and apply technology to new field study if appropriate. Continue weed control studies to test reliability. Establish the second planting of apple trees to evaluate compost rates for mature trees. 4. What were the most significant accomplishments this past year? What were the most significant accomplishments this past year? A. Single most significant accomplishment during FY 2004: Identified the true sex pheromone of the female dogwood borer. Dogwood borer, Synanthedon scitula Harris, is an increasingly important wood- boring pest of apple found throughout the eastern and midwestern United States and Canada, boring into and girdling apple trees planted on size- controlling or dwarfing rootstocks. Commercially available pheromone- baited traps have been considered to be an ineffective tool for monitoring the presence and activity of this insect because of poor captures as well as the large number of other clearwing moth species attracted to pheromone lures because the precise pheromonal components of the female dogwood borer had never been identified. In collaboration with Dr. Christopher Bergh, Virginia Tech. and Dr. Aijun Zhang, USDA-ARS, Beltsville MD, we have identified the true sex pheromone of the female dogwood borer. In current field evaluations, our experimental pheromone lures are overwhelmingly outperforming the best commercially available lure as we are capturing over 200 times more male moths with our experimental lures in West Virginia. The impact of this project will be to provide growers will a more effective pheromone-based monitoring tool that will allow them to better determine the need for and timing of insecticide applications. Furthermore, the identification of the dogwood borer pheromone now opens the door for alternative management strategies such as mating disruption and attract-and-kill technology, which ultimately could entirely eliminate the need for insecticide applications against this pest. B. Other significant accomplishments. Validated earlier findings and prepared a journal publication that demonstrated a direct relationship between the level of early season growth and fire blight lesion development and showed that multiple low- rate sprays of prohexadione-calcium (ApogeeRG) were not as effective as several high-rate treatments for suppressing fire blight in apple. Fire blight is one of the most destructive diseases in apple and this accomplishment enables growers to effectively suppress the disease. Three years of replicated field trials applied to young apple trees were used to develop this information. This information will provide apple growers with an effective technique for suppressing fire blight and can significantly reduce tree losses to this disease. Developed performance data on 23 new apple cultivars or apple selections. Apple growers and consumers are very much interested in new cultivars and data has been lacking on the performance of these cultivars under a wide range of climatic and edaphic conditions. Through replicated plantings, we demonstrated the fruit quality attributes of 23 selected apple cultivars when grown under mid-Atlantic conditions, identified the most adaptable cultivars for commercial production, and prepared and published the results combined with 13 other test sites throughout North America as part of the NE-183 Regional Project 'Multidisciplinary Evaluation of New Apple Cultivars'. Apple growers are now planting new apple cultivars that are adapted to their growing region which results in a higher quality product for the consumer. Demonstrated the blossom thinning ability of a specific natural oil for apple and peach. Thinning is necessary to enhance high quality annual crops in both apple and peach and current methods are costly and unpredictable. Replicated field trials were applied to determine the blossom thinning capacity of the material at several concentrations. This finding could lead to a commercial product for blossom thinning of apple and peach. Demonstrated that summer pruning novel peach tree growth habits (pillar and upright forms) with vertical, compact canopies may not enhance fruit red color at harvest even though light levels within the lower canopy are significantly improved compared to non-summer pruned trees. Summer pruning is a cultural practice recommended to peach growers to improve fruit color and cropping. Peach trees representing three growth habits (pillar, upright, and standard) were summer pruned annually over a four- year period and data collected on canopy light levels and fruit quality. These findings question the value of summer pruning as a recommended cultural practice in the new novel peach tree growth habits and could result in labor savings for growers wishing to grow these novel tree forms. Biological control of rosy apple aphid was found to be effective in early spring. Rosy apple aphid can cause significant damage to apples and the ability to rely on biological control for this pest could eliminate one insecticide application in early spring. Rosy apple aphid colonies were followed from egg hatch to when the aphids left apple in early summer, finding that over 90% of the aphid colonies were eliminated by the action of insect predators. This could result in the elimination of one insecticide application on apples in the eastern U.S. A new class of insecticides, termed sugar esters, has been developed that are biodegraded within 24 hours and have minimal environmental impact. New information was developed on the physio-chemical properties of sugar esters that have previously gone uncharacterized because of the novelty of the material. The contact angle of sugar esters was compared to other common surface active agents, surfactants and soaps, and on a variety of natural and artificial surfaces to understand its mode of action as an insecticide. This information will be useful in altering sugar ester chemistry to make sugar esters less sensitive to the hydrophobic surfaces of plants and lead to improved sugar ester insecticidal activity. Determined that an endogenous plant hormone, auxin, and the ratio of auxin to a second plant hormone, cytokinin, were significantly different among highly diverse crown architectures of peach. Trees used in high density plantings must have new crown architectures that provide a distribution of fruit and supporting leaves and branches which maximizes yield and not interfere with pest management yet the regulatory roles of chemical signals in tree crown development are not. Principle cytokinins were identified and the concentrations of auxin and cytokinins were measured in field-grown peach trees with different crown architectures. High auxin concentrations were associated with trees that had narrow branch angles and which grew in an upright orientation (Pillar trees) indicating that the gene associated with Pillar crown architecture was likely responsible for hyperproduction of auxin. This knowledge of a key biochemical component regulating peach crown architecture can contribute to efforts to culturally or genetically modify peach crowns to make them more amenable for high density plantings resulting in high density plantings of small fruit trees with the capacity to bear fruit early, provide higher yields, and require less pesticide use. Fruit size of 'Empire' and 'Liberty' apple were increased with foliar sprays of potassium fertilizer. Small fruit sizes have detrimental effect on growers' returns whereas large fruits, which are preferred by customers, command higher prices. Three post-bloom, potassium, foliar sprays were applied to several apple cultivars in two field seasons with similar results each year. This study will likely result in new nutrient management recommendations, larger fruit sizes, and potentially higher incomes for fruit producers. New concepts on mineral based and non-mineral based films were developed along with novel means of formulating these films. These patents protect the formulations used in particle film technology and extend the concept of particle films into new areas of agricultural and industrial uses. Two patents were filed: the first addressed formulation technology: 'Long-Chain Hydroxypolymer Compounds as Universal Spreading Agents', and the second addressed frost protection of plants: 'Method of Reducing Freeze and Chill Damage in Plants.' Particle film technology is a new tool for agriculture that will increase productivity and stability of a wide range of commodities. A non-reversible or slowly reversible long-term adaptation to heat and water stress was demonstrated in field studies with wine grapes conducted at CSIRO, Merbein, Victoria, Australia. Controlling early season vegetative growth in perennial crops, such as grape, is a limiting factor to production. Field studies demonstrated that early season stress reduced growth throughout the season, even after full irrigation was restored. The work provides a scientific basis for irrigation scheduling strategies that will reduce irrigation amounts. Demonstrated that pecan, an adapted and native species of the hot humid areas of the southern U.S., did not respond to kaolin-based particle film applications that were expected to reduce heat stress. Particle film technology is an emerging technology that has benefited many arid and semi-arid crop production systems but its environmental limits to mitigate heat stress needs to be defined. In conjunction with Texas A&M University, insect response and carbon assimilation responses to particle film applications were measured for two years, but no meaningful differences were documented. The work illustrated that pecan is very well adapted to its environment in the south U.S. and will not likely benefit from measures to reduce heat stress. Documented that apple peel not adapted to normal level of UV radiation, is damaged by the introduction of UV radiation. Apple fruit is susceptible to sunburn because, in many cases, the fruit change position overnight due the weight accumulation as the fruit matures; the causes of sunburn are not clear. In collaboration with HortResearch, Palmerston, New Zealand, potted apple trees were grown in the absence of UV radiation and exposed to normal levels of UV and then, challenged with UV radiation at maturity, resulting in sunburn damage and degradation of chlorophyll. The work demonstrated that UV adaptation requires 3-5 days and UV reflectants, such as particle film kaolin, can protect the photosynthetic mechanisms. Peach trees with extrafloral nectar glands were found to have greater numbers of parasitoids and less leaf feeding by insects than peach trees without extrafloral nectar glands. Increasing the number of insect biological control species in the orchard can make the orchard more resistant to pest damage. Orchards of the same cultivar of peach in which half the trees had extrafloral nectar glands and half lacked nectar glands were monitored for two years for the presence of beneficial insects and pest damage. Increased biological control of insect pests provided by this enhanced number of beneficial insects can reduce the need for insecticide treatments. C: Significant activities that support special target populations. None D. Progress Report: None. This is the final report for this project. It has been replaced by CRIS project 1931-21220-015-00D. 5. Describe the major accomplishments over the life of the project, including their predicted or actual impact. A particle film barrier for insects, sunburn protection, and heat stress reduction was invented, developed, and then commercialized by Engelhard Corp. as the brand name 'Surround'. It is the primary control agent for pear psylla control and sunburn reduction. 'Surround' proved to be highly effective in controlling pear psylla and reduced losses from sunburn by 50%. Particle film technology will become a major new tool for sustainable horticultural plant production and crop protection. Action Plan Components: 1.2.5., 1.2.6., and 3.2.5. Milestone FY2000. The present and the previous CRIS project made significant contributions to identifying uses and developing knowledge that was critical for the registration of a plant growth regulator, Apogee. Apogee controls vegetative growth in apple and pear and therefore reduces the amount of pesticide required for effective pest control. It could be used by 70% of the apple growers and is the most significant advance in the practical control of the destructive shoot blight stage of the fire blight disease in apple in more than 40 years. Apogee is a tool that will aid all apple and pear growers and make the U.S. fruit industry more globally competitive and sustainable by helping to reduce the amount of applied pesticides and improving fruit productivity and quality. Action Plan Components: 1.2.5., 1.2.6., and 3.2.5. Milestone FY2002. In a 15-year longterm study, the residues of diuron, simazine, or terbacil in the soil was measured, and results showed no build-up of the herbicides to have adverse effects on the young fruit trees. These results indicate that diuron, simazine, or tebacil are safe herbicides for use in orchard systems. Herbicides are widely used to control weeds that reduce fruit yield and quality and long-term studies demonstrating a neutral environmental effect support their continued use. Action Plan Components: 1.2.5., 1.2.6., and 3.2.5. Milestone FY 2002. Plastic reflective groundcover material and reflective kaolin formulations were identified that enhance red color in selected apple cultivars when applied to the orchard floor at least six weeks before harvest. Red coloration of the apple surface is a key factor in fruit quality of most apple cultivars and this technology can influence apple color development in the Appalachian growing region. Action Plan Components: 1.2.5. and 1.2.6. Milestones FY 2000 and 2004. Biological control of insect pests was enhanced by the interplanting of flowering plants and the use of compost in apple and peach orchards. Tree fruit production systems that are sustainable and utilize biological control of pests make the most efficient use of the natural resources. Predatory and beneficial insect populations increased when orchard habitat diversity was increased by planting various ground covers beneath fruit trees, applying composted chicken manure to the orchard floor for weed control and nutrient supply, and interspersing different species of fruit trees within the orchard. The new system of enhancing biological control of insects in orchards will reduce the use of synthetic pesticides without negatively affecting yield and fruit quality. Action Plan Components: 1.2.5., 1.2.6., and 3.2.5. Milestone FY 2003. 6. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end- user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? The sugar ester material, sucrose octantoate, was registered as an insecticide and miticide. This technology, available as 'Sucrocide', has been adopted by the honey bee industry where it is now commercially from the largest bee supplier, Dadant and Sons Sucrocide is one of the few materials that can control varroa mite on honey bees. The only negative aspect in its adoption by the bee industry is the extra effort in treating the hives with a spray which will hopefully be answered by a better application technology. This technology transfer is associated with the patent: Farone, B., Palmer, T., and G. J. Puterka. Improved Polyol Ester Insecticides. 2004. US Patent Number 6,756,046, June 29, 2004. A new pesticide delivery system technology was developed to reduce the amount of applied pesticides. This technology is under development through a CRADA with the Engelhard Corporation. of Iselin, NJ. The technology transfer is associated with the patent: Puterka, G.J. Puterka, D.M. Glenn, and D.G. Sekutowski. Pesticide Delivery System. 2003. US Patent Number 6,514,512. Feb.4, 2003. 7. List your most important publications in the popular press and presentations to organizations and articles written about your work. Popular Press: Columnar peach variety to be released. G. Warner, Good Fruit Grower 55(5):34-35, 2004. Managing fire blight in young trees. J. Norelli and S. Miller, Amer. Fruit Grower 124(4):36-37. Technology transfer through formal meetings: Morphological and hormonal relationships in shoots of pillar and standard peach trees. 2003 Annual Meeting of the Plant Growth Regulation Society of America. Vancouver, Canada. Novel uses of essential oils in fruit trees. 2003 Annual Meeting of the Cumberland Shenandoah Fruit Workers Conference. Winchester, VA. Soil amendment with hydrophobic kaolin particles to reduce weeds 2003 Annual Meeting of the American Society for Horticultural Science. Rhode Island. West Virginia University Winter Tree Fruit School. Progress Toward Behaviorally-Based Monitoring Strategies for Dogwood Borer and Stink Bugs. Kearneysville WV. West Virginia University Winter Tree Fruit School. Progress Toward Behaviorally-Based Monitoring Strategies for Dogwood Borer and Stink Bugs. Romney WV. Entomological Society of America, Annual Meeting. Mating behavior of the dogwood borer: rearing methods and potential control options. T.C. Leskey and J.C. Bergh. Cincinnati, OH. Entomological Society of America, Annual Meeting. Refinement of the pheromone-based monitoring system for dogwood borer, Synanthedon scitula. J. C. Bergh*, T. C. Leskey, A. Zhang, and J. F. Walgenbach. Cincinnati, OH. *Individual who made the presentation. Entomological Society of America, Annual Meeting. Effect of pheromone trap elevation on capture of dogwood borer, Synanthedon scitula Harris, in apple orchards. J.M. Sousa, J.C. Bergh, and T.C. Leskey. Cincinnati OH. Cumberland Shenandoah Fruit Worker Meetings. Assessing individual components of a monitoring system for plum curculio. Winchester VA. Cumberland Shenandoah Fruit Worker Meetings. Stink bug response to five trap types in apple and peach orchards. H.W. Hogmire, and T. C. Leskey. Winchester VA. Miller, S. and T. Tworkoski. Controlling Excessive Vegetative Growth. Appalachian Fruit Research Station Fact Sheet, November 2003. Disease susceptibility of new apple cultivars and horticultural performance, 2004 Virginia/WV Grown Conference and trade Show, Richmond, VA. Apple cultivars for the mid-Atlantic industry, 145th Annual meeting Mid- Atlantic Fruit and Vegetable Convention, Hershey, PA. Performance of new peach tree growth types, Western Maryland Regional Fruit Growers Meeting, Keedysville, MD. The Use of Apogee for suppressing fire blight in young apple trees, Western Maryland Regional Fruit Growers Meeting, Keedysville, MD.

Impacts
(N/A)

Publications

  • Leskey, T.C., Wright, S.E. 2004. Monitoring plum curculio, conotrachelus nenuphar (herbst) (coleoptera: curculionidae) populations in apple and peach orchards in the mid-atlantic. Journal of Economic Entomology. 97:79- 88.
  • Bergh, J., Leskey, T.C., Zhang, A. 2004. Discrimination by male dogwood borer, synanthedon scitula harris (lepidoptera: sesiidae) to traps baited with commercially available pheromon lures. Journal of Economic Entomology. 97:344-352
  • Hampson, C.R., Mcnew, R., Miller, S.S. 2004. Performance of 'braeburn', 'golden delicious' and 'yataka' apple on mark and m.9 rootstocks at multiple locations across north america. Journal of American Pomological Society. 58:78-89, 2004
  • BROWN, M.W., SCHMITT, J.J., ABRAHAM, B.J. SEASONAL AND DIURNAL DYNAMICS OF SPIDERS (ARANEAE) IN WEST VIRGINIA ORCHARDS AND THE EFFECT OF ORCHARD MANAGEMENT ON SPIDER COMMUNITIES. ENVIRONMENTAL ENTOMOLOGY. 2003. Vol. 32(4)P 830-839.
  • Mathews, C.R., Bottrell, D.G., Brown, M.W. 2004. Habitat manipulation of the apple orchard floor to increase ground-dwelling predators and predation of cydia pomonella (say) (lepidoptera: tortricidae). Biological Control. 300:265 - 273 (2004)
  • Tworkoski, T. 2003. Morphological and hormonal relationships in shoots of pillar and standard peach trees. Society of America Plant Growth Regulator Proceedings. 30:190
  • Tworkoski, T. 2004. Characteristics and management of peach and apple tree crowns. Plant Growth Regulator Society of America Meeting. 32:31
  • Bell, R.L., Puterka, G.J. 2003. Analysis of modes of host plant resistance to pear psylla. Eucarpia Symposium on Fruit Breeding and Genetics Programme and Abstracts, p. 32, 2003.


Progress 10/01/02 to 09/30/03

Outputs
1. What major problem or issue is being resolved and how are you resolving it? The national tree fruit industry is facing the loss of key insecticides by FQPA (Food Quality Protection Act), in addition to continual development of insect resistance to insecticides. The presence of agrochemicals in drinking water and waterways demonstrates the need to efficiently manage nutrients, water, and the application of agrichemicals. Concerns for human health and the environment have led to reduced pesticide and fertilizer use through the development of alternative pest and fertilizer practices in orchard management systems; however, these practices need to be integrated to maintain high orchard productivity and economic sustainability. Research is being conducted on: 1) the ecology of insects involved in biological control, including insect behavior, 2) new methods of monitoring key insect pests in order to effectively manage and reduce pesticide usage, 3) the mechanisms of insect control with particle films, sugar esters and other materials for insect control, 4) the role of heat, water and nutrient stress in plant productivity and fruit quality, 5) the mechanism of vegetative growth control and inducing fruit buds, and 6) the role of training and orchard floor management methods to affect light and temperature within the canopy. Alternative insect control products have been developed, such as the particle film, Surround, and sugar esters. New methods of orchard management enhance biological control of orchard pests, improve fruit quality and yield, reduce weed competition, and reduce the amount of pesticides and fertilizers applied in the orchard system. The incorporation of plant bioregulators into orchard systems reduces excess vegetative growth and habitat for insect pests while increasing spray efficiency and so reduces the amount of pesticides needed to control a pest. 2. How serious is the problem? Why does it matter? Reduction in the use of pesticides is a national priority. Pesticide application and pruning account for over 50% of the cost of fruit production in the eastern U.S. where conditions favor vegetative growth and heavy pest pressure. The loss of key insecticides in 2001 limits grower ability to control insect pests and increases the risk of significant fruit loss and increases the cost of production. More efficient cultural management practices which integrate the soil and climatic conditions of the region into the production system will improve production efficiency, lower pesticide use and production costs, and increase competitiveness and profitability to fruit growers. Without continued improvement in cultural management practices, tree fruit growers throughout the eastern U.S. will cease to be competitive in a global market and the industry will be lost to foreign imports. 3. How does it relate to the National Program(s) and National Program Component(s) to which it has been assigned? The research addresses the critical issue of National Programs 304 (Crop Protection and Quarantine) and 305 (Crop Production) for food safety and reduced chemical and mineral release from agricultural activities. The research relates to traditional agriculture as well as small farm and organic agriculture. 4. What were the most significant accomplishments this past year? A. Single Most Significant Accomplishment in FY2003: There is a need to identify new and safer chemistries with insecticidal activity. Research was conducted with AVA Chemical Ventures under a CRADA to identify a sugar ester chemistry with superior insecticidal activity and formulation properties and to characterize the structure- function relationships of sugar esters chemistries with insecticidal activity. The research resulted in a patent, Polyol Ester Insecticides and Method of Synthesis, US patent No. 6,419,941, issued July 2002; and a patent filing, Improved Polyol Ester Insecticides, which was filed in August 2002. Patent rights for Sucrose octanoate is being licensed from the ARS by AVA Chemical Ventures and AVA Chemical Ventures has entered a distribution agreement with a major pesticide company, CertisUSA, LLC, which intends on making sucrose octanoate commercially available as a miticide in 2003. B. Other Significant Accomplishments: 1) Excessive shoot growth in most apple cultivars makes trees highly susceptible to the fire blight bacteria, but pronounced growth control when trees are one- to four-years-old is not desirable. Prohexadione- calcium (Apogee), a very effective shoot growth retardant, was applied to young apple trees at low doses to determine if a threshold rate existed that would suppress fire blight without excessive growth reduction. Field studies using inoculated trees treated with various rates of Apogee confirmed preliminary findings and firmly established a relationship between the Apogee doses, shoot growth, and degree of fire blight suppression. These results provide apple growers with definitive data in support of a cultural management program for treating fire blight- susceptible young apple plantings and reducing the need for antibiotic sprays, the only present method of control. 2) Although the plum curculio is considered to be a key pest of apple in eastern North America, peach and plum in the southern United States, and cherry and blueberry throughout the east, there are no effective monitoring methods to detect its entry into fruit orchards to better time insecticide sprays to control this pest, nor is there an alternative control method. We evaluated responses of plum curculio to four trap types and four bait treatments in commercial and unmanaged apple and peach orchards. None of the trap types with any of the bait combinations provided a reliable indication of the damaging potential of the plum curculio population indicating that more competitive baits and traps are needed; thus, in collaboration with Dr. Aijun Zhang, Research Chemist at ARS-Beltsville, MD, we identified compounds present in headspace volatile collections from plum trees to test the potential of these compounds to increase the effectiveness of baited traps as a monitoring technique for plum curculio. The potential impact of this project will be to provide apple growers with an effective monitoring technique based on behavioral and chemical ecology that could eventually lead to an alternative control strategy for plum curculio. 3) A major obstacle to understanding how modifications in particle film affect insect control is the quantification of particle film structure and other characteristics, specifically film thickness and friability on plant surfaces that alter insect behavior. We developed a friability measurement device and film thickness probe that enables the characterization of various particle films and comparison between film types. Different film types were characterized and insect behavior was measured on different film types. These instruments will allow comparisons between particle films and provide the ability to correlate these film characteristics with efficacy against insects and plant physiology to identify how mechanisms of action of particle films are affected by modifying particle film structure. 4) Pear psylla is a major insect pest of pear production in the U.S. Pear psylla response to color was measured throughout the growing season in the field. Pear psylla was found to be attracted to yellow after petal-fall but to no particular color after August. Pear psylla populations are routinely monitored by yellow sticky traps but this study established that this monitoring tool is only effective between May and August and that other monitoring methods are needed. 5) Understanding the mechanisms of action for insecticides is key to designing more effective and safer insecticides. A dynamic tensiometer and contact angle measuring devices were used to study the behavior of surface active materials (particle films, surfactants,and oils) at the plant surface-material interface. Initial studies have determined that sugar esters do not behave like surfactants and conventional insecticides on the plant surface. These results suggest sugar esters may kill insects by novel, yet unknown mechanisms. 6) Dogwood borer is an increasingly important wood-boring pest of apple in eastern North America and pheromone-based monitoring traps for this insect have provided inconsistent results in the past. We evaluated the response of male dogwood borer to four commercially available pheromone lures in commercial apple orchards in West Virginia and Virginia in collaboration with Virginia Tech. and chemically analyzed the pheromone lures in collaboration with USDA-ARS, Beltsville MD. The Scenturion dogwood borer lure captures the greatest number of dogwood borer, and the smallest number of other species. Chemical analysis revealed a common compound in all lures, but a higher percentage of the compound in the Scenturion Lure. The potential impact of this project will be to provide growers with a more effective monitoring system for this increasingly important pest and lead to alternative control strategies such as mating disruption. 7) Stink bugs are a common pest of stone fruit and recently have emerged as an increasingly important pest of apple, which necessitates the development of effective monitoring systems for this pest. We evaluated pyramid traps coated with 'industrial safety yellow' exterior latex gloss enamel paint, placed between peach and apple trees, and baited with the Euschistus spp. aggregation pheromone, methyl 2,4-decadienoate. The Baited yellow pyramid traps captured more stink bugs than unbaited pyramid traps and baited and unbaited clear-jar traps hung in the canopies. 8) The rosy apple aphid is the most damaging aphid on apple in the eastern US because of the damage it causes to fruit, yet control of this pest must be done before damage is visible because, once damage is seen, the aphids are protected from most insecticides by the curled leaves in which they feed. Field studies in AFRS orchards showed that predation by the multicolored Asian ladybeetle in early spring, before and during apple bloom, significantly reduces the number of rosy apple aphid colonies. This suggests that the ladybeetles could be an effective biological control of the aphid pest, with the potential for eliminating one or more insecticide applications in apple and reduce fruit damage. 9) Particle film technology was jointly developed by USDA-ARS and the Engelhard Corp. and is widely used in the semiarid U.S.; however, rainfall in the temperate U.S. limits its utility as an insecticide because of rainfall wash-off. Studies determined that particle film composition can be altered to improve spreading upon leaves while providing resistance to rain. These modifications improved both particle film rainfastness on plants and efficacy against certain arthropod pests under high rainfall conditions in the eastern U.S. Rainfast and effective particle film materials will reduce the use of synthetic insecticides in temperate regions. 10) Tree fruit crops develop shaded areas due to the extensive canopy, and reduced light will decrease photosynthesis, yield and quality. A particle film material, Surround-WP developed under a CRADA with Engelhard Corp., was applied directly to apple trees and a new particle film formulation was applied to the driveway between trees to reflect photosynthetically active radiation (PAR) into the canopy at AFRS. Tree photosynthesis, yield, and quality were increased as a result of the PAR reflection in apple trees. Particle film technology was developed under a CRADA with the Engelhard Corp. and provides new tools to improve grower returns and productivity while reducing the environmental impact of agriculture on the environment. 11) The susceptibility of new apple cultivars to the black rot fungus Botryosphaeria obtusa is an important criterion in the commercial acceptance of these cultivars in the mid-Atlantic and southeastern United States. In West Virginia, in cooperation with Dr. Alan Biggs at the West Virginia University Fruit Research Center, methods were developed and utilized in controlled field and laboratory inoculation studies for 21 relatively new and two established apple cultivars grown in the NE-183 Regional Project planting. Results from the two-year study permitted the selected apple cultivars to be classified from most susceptible to least susceptible to the black rot organism. Compared to previous cultivar rankings, the results of the present study indicate that no new apple cultivars from the 1995 NE-183 planting show greater resistance to black rot than current standard cultivars and this information is aiding apple growers and extension fruit specialists in selecting the most disease resistant apple cultivars for planting. 12) Shade cast by an apple tree's own foliage and from cloud cover reduces fruit bud initiation and lowers fruit quality. Field studies have been conducted since 1998 at the Appalachian Fruit Research Station to examine the effect of partial and continuous shade on growth and fruiting in apple to simulate shading within an apple tree. Recent results demonstrate that a daily 6 HR shade period has limited or no influence on growth, fruit set, or return bloom; continuous (24 HR) 73% (of full sunlight) shade increases extension shoot growth and reduces fruit set slightly; while 95% shade resultes in 100% fruit abscission and a loss in leaf chlorophyll. All shade treatments were initiated 3 weeks after full bloom and terminated on September 30. These studies will establish critical levels of light that will influence future pruning and tree orientation practices and illustrates to apple growers the need for good pruning practices that result in open, light accessible canopies. 13) Novel peach tree growth habits offer peach growers the potential for high-density plantings that could lead to higher per acre yields than are currently possible with standard growth habits. Early studies indicate that upright growth habit peach trees yielded more per acre than pillar and standard growth habit trees when planted at equal spacing; however, at optimal tree spacing for each tree type, pillar peach trees yielded 124% more fruit per acre than standard trees and 9% more than upright growth habit trees. Tree spacing has a significant effect on growth, pruning time, and yields per tree, but pruning system (central leader or multiple leader) has very limited effect on these variables. This information demonstrates the feasibility of new peach tree growth habits to fruit growers and aids in their decision making process concerning new peach tree plantings to optimize productivity and fruit quality. 14) Alternative weed management tools are needed due to public perception and possible regulatory restriction of some synthetic herbicides. Organic wastes, including poultry litter and sawdust, were used as mulches in combination with trimming or a natural product herbicide, eugenol, to suppress weeds in orchards. Results demonstrated that mulch effectiveness increased with depth and mulch was as effective as a residual herbicide for annual weed control but, mulch provided only partial control of perennial weeds while eugenol provided additional control of weeds that grew through the mulch. Combinations of these technologies may become effective alternate weed management tools for orchard systems. 15) Certified organic growers have a limited amount of materials that can be effectively used to control weeds. We evaluated a kaolin based herbicide that meets USDA Organic Standards, and found that it provided effective weed control. A patent was filed, and commercial development was initiated. A new and organically certified weed control material would reduce crop losses to organic growers. 16) There is a lack of effective and environmentally friendly methods of eliminating zinc deficiencies in deciduous fruit trees despite the widespread occurrence of zince deficiencies in the United States and the known association of these deficiencies with poor tree growth, depressed yields, and inferior fruit quality. We studied the effectiveness of various formulations of zinc applied to the root collar of apple plants under greenhouse conditions. The effectiveness of zinc absorption and translocation within the plants was high, as opposed to low uptake rates and limited translocation of zinc to new flushes of growth when absorbed from foliar sprays, which are commonly used to alleviate the metal's deficiencies. Due to effective zinc absorption and high mobility in plants, the new method of zinc application has the potential of reducing the amount of zinc needed to correct deficiencies, produce more lasting effects, and greatly reduce the danger of zinc accumulation in the soil to levels of regulatory concern. 17) As consumers pay premium prices for large apples, cultural methods that stimulate fruit growth are highly desirable. We elucidated the effect of foliar applications of two potassium salts on fruit growth of three apple cultivars under field conditions. Three foliar sprays with potassium after bloom resulted in significantly larger apples on two of the three cultivars studied. The potential impact of this study will be to help apple growers realize higher returns through the increased production of larger fruit. C. Significant Activities that Support Special Target Populations: None. 5. Describe the major accomplishments over the life of the project, including their predicted or actual impact. (1) Alternative pest control and more efficient production methods are needed because the national tree fruit industry is facing the loss of key insecticides in 2003 by FQPA (Food Quality Protection Act) and global competition is limiting markets. A particle film barrier for insects, sunburn protection, and heat stress reduction was invented by ARS scientists, commercialized by Engelhard Corp. as the brand name 'Surround', and applied to more than 300,000 acres of tree fruit in 2002, and 500,000 acres in 2003, primarily for pear psylla control and sunburn reduction. 'Surround' proved to be highly effective in controlling pear psylla and reduced losses from sunburn by 50%. Particle film technology will become a major new tool for sustainable horticultural plant production and crop protection. (2) Excessive vegetative growth in fruit trees reduces fruit yield and quality and interferes with pesticide coverage and pest control. The present and the previous CRIS project have made significant contributions to identifying uses and developing knowledge that is critical for registration of a plant growth regulator, Apogee. Apogee controls vegetative growth in apple and pear, thereby reducing the amount of pesticide required for effective pest control; could be used by 70% of the apple growers; and is the most significant advance in the practical control of the destructive shoot blight stage of the fire blight disease in apple in more than 40 years. Apogee is a tool that will aid all apple and pear growers and make the U.S. fruit industry more globally competitive and sustainable by helping reduce the amount of applied pesticides and improving fruit productivity and quality. (3) Herbicides are widely used to control weeds that reduce fruit yield and quality but social, ecological, and legal issues may impact their use in the future. The impact of long-term herbicide application on herbicide residues in soil, weed community dynamics and on growth of newly planted fruit trees was investigated. Despite 15 years of long- term use, no build-up of diuron, simazine, or terbacil residues in the soil was detected and the herbicides had no adverse effects on the young fruit trees. These results indicate that diuron, simazine, or tebacil are safe herbicides for use in orchard systems, but long-term use of terbacil may inhibit growth of newly-planted peach trees. (4) Red coloration of the apple surface is a key factor in consumer acceptance of most apple cultivars. Studies were established to evaluate the potential of reflective groundcovers to increase light scatter into the apple tree in order to improve apple color development. The research demonstrated that plastic reflective groundcover material and reflective kaolin formulations can enhance red color in selected apple cultivars when applied to the orchard floor at least 6 weeks before harvest and canopy form and/or training system can influence apple color development in the Appalachian growing region. The reflective groundcover materials are now commercially available for use by tree fruit growers. (5) Tree fruit production systems that are sustainable and utilize biological control of pests make the most efficient use of the natural resources. Predatory and beneficial insect populations increased when orchard habitat diversity was increased by planting various ground covers beneath fruit trees, applying composted chicken manure to the orchard floor for weed control and nutrient supply, and interspersing different species of fruit trees within the orchard. Peach harvest of high quality low-spray peaches grown with flowering ground cover plants, mating disruption for oriental fruit moth, and reduced insecticides was similar to a conventionally managed check orchard in total yield, fruit size, and amount of insect damage. The new system of enhancing biological control of insects in peach orchards will reduce the use of synthetic pesticides without negatively affecting yield and fruit quality. 6. What do you expect to accomplish, year by year, over the next 3 years? FY 2004: 1) Evaluate effectiveness of flowering plants as a trap crop for attracting stink bugs out of apple orchards as a control of fruit damage. If economically effective, protocols will be developed for fruit growers. 2) Test experimental lures for plum curculio based on identification of headspace volatiles from plum trees in experimental orchards and for dogwood borer based on correct pheromone identification in commercial orchards. 3) Complete field evaluations on the use of light-reflecting particle film materials as herbicides. The reliability of weed control and the amount of light reflected in the plant canopy will be assessed and this information will be used by the CRADA partner (Engelhard Corp.) to make a decision to commercialize a formulation. If commercialized, the weed control product will likely meet National Organic Standards. 4) Design and conduct studies to confirm preliminary results on the use of plant growth regulators to control the flesh cracking disorder in 'GoldRush' apple. 5) Provide growth and carbon partitioning data sets to collaborator for testing in the Apple C Model. 6) Report on the early performance of novel peach tree growth habits. 7) Characterize how particle film structure changes when formulation components are changed. Characterize physical characteristics of surface active materials. Study the mechanisms of action of particle film and surface active materials on insects and plant physiology. CRADA renewals will be pursued with AVA Chemical Ventures and Engelhard Corp. to develop new chemistries or new uses. 8) Complete morphological characterization of selected peach growth habits in field and proceed with determination of auxin and cytokinin profiles in these growth habits to establish baseline relationships of hormones and shoot morphology. 9) Develop new information on the effect of potassium nutrition on fruit size of apple. Conditions under which improvements in fruit size are expected will be evaluated ( fruit set, potassium status at different times after flowering). FY 2005: 1) Complete guidelines on flowering species to enhance biological control of insect pests in apple orchards. The information will be published and used by pest management professionals to advise growers. 2) Test the most attractive experimental lures for plum curculio in grower orchards and patent dogwood borer pheromone lures. 3) Complete growth chamber and field evaluations on the use of hydrophobic formulations as barriers to freezing under radiation frost conditions. The reliability and degree of freeze protection will be assessed and this information will be used by the CRADA partner (Engelhard Corp.) to make a decision to commercialize a formulation. 4) Collaborate with pomologist and extension fruit specialist at Pennsylvania State University and establish a grower test orchard of novel peach tree growth habits. Begin tree training studies under grower cultural management system to evaluate yield and fruit quality potential. 5) Establish a new apple planting to test the effect of supplemental light during bloom and early fruit development on growth, flowering, fruiting, and C partitioning. 6) Continue the characterization of particle film structure and surface active material physical properties in response to composition changes. Determine how these changes affect efficacy against insects and plant physiology. 7) Establish first year data relating effects of cultural practices, including pruning, on hormone and morphological changes in different peach growth habits. 8) Complete field studies on the effect of factors such as fruit set, fruit size, and potassium nutrition status on the response of apple to additional potassium applications. FY 2006: 1) An orchard planting is developed and provided to growers to incorporate flowering plants and extrafloral nectar sources for increasing biological control of apple pests. 2) Apply for patents for plum curculio lures and test mating disruption dispensers for dogwood borer. 3) New methods of reducing water stresses and yield losses through subsurface irrigation and particle film technology are provided to growers. 4) Complete the evaluation of the 1995 NE-183 Apple Cultivar Project selections and publish findings. Establish expanded planting (minimum of 50 trees) of the two most promising selections from the 1999 NE-183 Project for additional horticultural performance evaluation. 5) Modify particle film and surface active materials composition to increase efficacy or to add additional mechanisms of action against insects or to enhance plant physiology. Determine routes of new research in the areas of particle films and surface active agents.be used to improve current particle film and sugar ester chemistries. Develop new CRADA=s with interested companies. 6) Complete data collection on three year evaluation of cultural and genetic interactive effects on hormone influences on peach tree morphology. Information will be provided to horticulturists and breeders developing peach trees with vegetative traits needed for high density orchards. 7) Compile and publish data on the effect of potassium nutrition on apple fruit size and the factors affecting this response. If results are positive, the technology will be transferred to apple fruit growers. 7. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end- user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? A. Sugar Esters: The sugar ester, Sucrose Octantoate, became registered as an insecticide with the U.S. E.P.A. in November 2002. AVA Chemical Ventures will market Sucrose octanoate with Certis USA who plans on launching the sugar ester as a miticide in Spring 2004. B. Particle Film Technology. Particle film technology is available nationwide as 'Surround-WP Crop Protectant'. It is used for insect control in organic and conventional production systems to control a range of insect pests and to reduce heat stress and sunburn damage. Particle film, Surround WP, usage for control of glassy-winged sharpshooter in grape was transferred to USDA-APHIS and the California Department of Food and Agriculture last year and its use has been expanded to other control zones in California. A prototype commercial product for the reflection of light into plant canopies is being evaluated by Engelhard Corp. Trained 3 visiting scientists from Turkey who were funded by the USDA Cockran Fellowship Program to teach them various aspects of particle film technology, July 14-July 25, 2003, so collaborative research can be established. C. Prohexadione-calcium. Information on the use of prohexadione- calcium (ApogeeRG) was presented to scientists, technical representatives, and fruit growers. The information and science is immediately available to end-users and includes information on reducing vegetative growth of fruit trees, decreased pesticide application and reductions in fire blight incidence. Management guidelines are available for use with young apple trees. D. Technology Transfer through formal meetings Presentation - Apple and peach tree response to scoring and restriction of trunks. 2002 Annual Meeting of the Plant Growth Regulation Society of America. Nova Scotia, Canada. Presentation - The synthesis and biological evaluation of eugenol derivatives as potential herbicidal agents. 2002 Annual Meeting of the Plant Growth Regulation Society of America. Nova Scotia, Canada. Invited presentation - Nitrogen and phosphorus availability and plant uptake from soil treated with composted and uncomposted poultry litter. Composting in the Southeast Conference and Exposition (Palm Harbor, FL, Oct. 6-9, 2002). Presentation "Biological Control of Rosy Apple Aphid." Presented to Eastern Branch, Entomological Society of America, Harrisburg, PA, March 2003. Poster presentation on particle film mineral amendments affect on mites in apple at the Annual Entomological Soc., Ft. Lauderdal, FL, Oct, 2002. Presentation-"Trap Cropping to control Heteroptera Damage in Peach and Apple Orchards." to Entomological Society of America meeting, Fort Lauderdale, FL, November, 2002. Invited Presentation- Virginia Grown Conference and Trade Show. Virginia/West Virginia State Horticultural Societies. Behaviorally based strategies for monitoring and management of plum curculio. Richmond VA. Invited Presentation- Rutgers University. Department of Entomology. Behaviorally Based Monitoring Strategies for Plum Curculio. New Brunswick NJ Paper Presentation. Entomological Society of America, Eastern Branch Meeting. Mating behavior of the dogwood borer: implications for rearing. T. C. Leskey and J. C Bergh. Harrisburg, PA. Paper Presentation. Entomological Society of America, Eastern Branch Meeting. Behavioral Manipulation as the basis for future management strategies for the dogwood borer. J. C. Bergh* and T. C. Leskey. Harrisburg, PA. * Individual who made the presentation. Poster Presentation. Entomological Society of America, Eastern Branch Meeting. Trap evaluation for monitoring stink bugs in apple and peach orchards. H. W. Hogmire. and T. C. Leskey. Harrisburg, PA. Paper Presentation. Entomological Society of America, Eastern Branch Meeting. Possible suppression of potato leafhopper feeding by Apogee: implications for fire blight control on apple. K. P. Leahy*, D. W. Greene, W. R. Auto, J. N. Norelli and T. C. Leskey. Harrisburg, PA. . * Individual who made the presentation. Paper Presentation. Cumberland Shenandoah Fruit Worker Meetings. Comparison of two trap types for stink bug monitoring in apples and peaches. Hogmire, H.*, T. C. Leskey and S. E. Wright. Winchester, VA. *Individual who made the presentation. Paper Presentation. Cumberland Shenandoah Fruit Worker Meetings. Monitoring plum curculio in apple and peach orchards in the mid-Atlantic. Leskey, T.C.* and S. E. Wright Winchester, VA. * Individual who made the presentation. Paper Presentation. Cumberland Shenandoah Fruit Worker Meetings. Refining the pheromone-based monitoring system for dogwood borer. . Bergh, J. C.* and T. C. Leskey. Winchester VA. * Individual who made the presentation Paper Presentation. Entomological Society of America, Annual Meeting. Life History of Dogwood Borer in Apple. Bergh, J.C *, and T. C. Leskey. Ft. Lauderdale, FL *Individual who made the presentation. Paper Presentation. Entomological Society of America, Annual Meeting, Initiation of Dogwood Borer Infestation in Apple Orchards. T. C. Leskey and J. C. Bergh. Ft. Lauderdale, FL. Paper Presentation. Entomological Society of America, Eastern Branch Meeting. Preliminary Evidence for bivoltinism for dogwood borer in apple in the mid-Atlantic region. Bergh, J.C *, T. C. Leskey and S. E. Wright. Ocean City, MD. *Individual who made the presentation. Oral presentation - " Horticultural performance of apple cultivars in the NE-183 planting in West Virginia", Cumberland-Shenandoah Fruit Workers Conference. 8. List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: This does not replace your peer-reviewed publications listed below). Oral presentation - Surround; A New Product for Fruit Production. 2003 Southeastern Fruit growers Conference, Savannah, Ga. Oral presentation - Particle Film Technology-A new Tool for Fruit Production. Calif. Extension workshops at 9 locations in Salinas, Fresno, Napa, Sacramento, CA. Oral presentation-"Bitter Pit, Calcium Deficiency or Stink Bug Damage." 2003 Mid-Atlantic Fruit and Vegetable Convention, Hershey, PA, Feb. 2003. Oral presentation-"Irrigation in the Mid-Atlantic States." 2003 Mid- Atlantic Fruit and Vegetable Convention, Hershey, PA, Feb. 2003. Oral presentation-"Bitter Pit, Calcium Deficiency or Stink Bug Damage," to Northern Virginia Tree Fruit School, Winchester, VA, Feb. 2003. Oral presentation - "New apple cultivars of merit in the NE-183 trial and others", North Jersey Tree Fruit Production Meeting for Commercial Growers. Oral presentation - " Comparing less than perfect apple cultivars", WVU Fruit Production School.

Impacts
(N/A)

Publications

  • Puterka, G.J., Bocchetti, C., Dang, P., Bell, R.L., Scorza, R. Pear transformed with a lytic peptide gene for disease control affects nontarget organism, pear psylla (homoptera: psyllidae). 2002. Journal of Economic Entomology. v.95. p.797-802.
  • Puterka, G.J., Reinke, M., Luvisi, D., Ciomperik, M.A., Bartels, D., Wendel, L., Glenn, D.M. Particle film, Surround WP, effects on glassy- winged sharpshooter behavior and its utility as a barrier to sharpshooter infestations in grape. 2003. Online. Plant Health Progress doi:10.1094/PHP- 2003-0321-01-RS.
  • Tworkoski, T. Herbicide effects of essential oils. Weed Science. 2002. v. 50. p.425-431.
  • Swietlik, D. Plant Nutrition. Concise Encyclopedia of Temperate Tree Fruit. T.A. Baugher and S. Singha, eds. 2003. The Haworth Press, Inc., Binghamton, NY. p. 251-257.
  • Swietlik, D. Soil Management and Plant Fertilization. In: Concise Encyclopedia of Temperate Tree Fruit. 2003. T.A. Baugher and S. Singha (eds.). The Haworth Press, Inc., Binghamton, NY. p.295-302.
  • Biggs, A.R., Miller, S.S. 2004. Relative susceptibility of selected apple cultivars to fruit rot caused by botryosphaeria. Hortscience. 39:303-306, 2004
  • Brown, M.W., Tworkoski, T. 2004. Pest management benefits of compost mulch in orchards. Agricultural Ecosystems and Environment. (2004) 103:465-472
  • Brown, M.W. Functional biodiversity and agro-ecosystems management: 2. Role in integrated fruit production. 2001. Integrated Fruit Production, IOBC/wprs Bull. 24(5)p.5-11.
  • Brown, M.W. Are flowering plants taboo in peach orchards? Proceedings of 5th International Symp. Peach. 2002. Acta Horticulturae v.592. p.659-662.
  • Brown, M.W. Intraguild responses of aphid predators on apple to the invasion of an exotic species, 2003, Harmonia axyridis. BioControl v.48, p.151-153.
  • Glenn, D.M. Irrigation of Deciduous Tree Fruit Crops, In: Concise Encyclopedia of Temperate Zone Tree Fruits. T.Baugher and S. Singha, eds. 2003. Press, Inc. p.149-154.
  • Akey, D.H., Arthur, F.H., De Lucca II, A.J., Gibson, D.M., Harrison Jr., H. F., Peterson, J.K., Gealy, D.R., Tworkoski, T., Wilson, C.L., Morris, J.B. ARS Research on Natural Products for Pest Management. Pest Management Science. 2003. v.59. p.708-717.
  • Glenn, D.M. Tree Canopy Temperature Management. In: Concise Encyclopedia of Temperate Zone Tree Fruits. T. Baugher and S. Singha, eds. 2003. Haworth Press, Inc. p.355-358.
  • Glenn, D.M. Water Relations of Tree Fruit Crops. In: Concise Encyclopedia of Temperate Zone Tree Fruits. 2003. T. Baugher and S. Singha, eds. Haworth Press, Inc. p.361-366.
  • Glenn, D.M., Erez, A., Puterka, G.J., Gundrum, P. Particle Films Affect Carbon Assimilation and Yield in 'Empire' Apple. 2003. Journal of American Society of Horticulture Science. v.128. p.356-362.
  • Leskey, T.C. Insects and Mites. In: Concise Encyclopedia of Temperate Zone Tree Fruits. 2003. Baugher, T. and S. Singha, eds. Haworth Press, Inc. p. 137-148.
  • Leskey, T.C. Plant-Pest Relationships and the Orchard Ecosystem. 2003. In: Concise Encyclopedia of Temperate Zone Tree Fruits. Baugher, T. and S. Singha, eds. Haworth Press, Inc. p.259-264.
  • Leskey, T.C. Sustainable Orcharding. In: Concise Encyclopedia of Temperate Zone Tree Fruits. Baugher, T. and S. Singha, eds. 2003. Haworth Press, Inc. p.319-326.
  • Mathews, C.R., Bottrell, D.G., Brown, M.W. A comparison of conventional and alternative understory management practices for apple production: multi-trophic effects. 2002. Applied Soil Ecology v.21. p.221-231.
  • Miller, S.S. Dwarfing. In: Concise Encyclopedia of Temperate Tree Fruit. 2003. T.A. Baugher and S. Singha, eds. The Haworth Press, Inc., Binghamton, NY. p.65-72.
  • Miller, S.S. Harvest. In: Concise Encyclopedia of Temperate Tree Fruit. T. A. Baugher and S. Singha, eds. 2003. The Haworth Press, Inc., Binghamton, NY. p.121-129.
  • Miller, S.S. 2003. Horticultural performance of apple cultivars in the ne- 183 planting in west virginia. Annual Cumberland Shenandoah Fruit Workers Conference. Vi, 78:189-202, 2002
  • Miller, S.S., Tworkoski, T. 2003. Regulating vegetative growth in deciduous fruit trees. Plant Growth Regulation Society of America Quarterly.Volume 31, No. 1, Pgs 8 - 46.
  • Miller, S.S. and Greene, G.M. The use of reflective film and ethephon to improve red skin color of apples in the mid-Atlantic region of the United States, HortTechnology 2003, v.13(1):90-99.
  • Preusch, P.L., Adler, P.R., Sikora, L.J., Tworkoski, T.J. Nitrogen mineralization rates and phosphorus availability in composted and uncomposted poultry litter. Journal of Environmental Quality. 2002. v.31. p.2051-2057.
  • Puterka, G.J., Farone, B., Palmer, T., Barrington, T. Structure-function relationships affecting the insecticidal and miticidal activity of sugar esters. 2003. Journal of Econ. Entomology. v96. p.636-644.


Progress 10/01/01 to 09/30/02

Outputs
1. What major problem or issue is being resolved and how are you resolving it? The national tree fruit industry is facing the loss of key insecticides in 2002 by FQPA (Food Quality Protection Act), in addition to continual development of insect resistance to insecticides. The presence of agrochemicals in drinking water and waterways demonstrates the need to efficiently manage nutrients, water, and the application of agrochemicals. Concerns for human health and the environment have led to reduced pesticide and fertilizer use through the development of alternative pest and fertilizer practices in orchard management systems; however, these practices need to be integrated to maintain high orchard productivity and economic sustainability. Research is being conducted on: 1) the ecology and behavior of insects involved in biological control, 2) new methods of monitoring key insect pests in order to effectively manage and reduce pesticide usage, 3) the mechanisms of insect control with particle films, sugar esters and other materials for insect control, 4) the role of heat, water and nutrient stress in plant productivity and fruit quality, 5) the mechanism of vegetative growth control and inducing fruit buds, and 6) the role of training and orchard floor management methods to affect light and temperature within the canopy. Alternative insect control products have been developed, such as the particle film, Surround, and sugar esters. New methods of orchard management enhance biological control of orchard pests, improve fruit quality and yield, reduce weed competition, and reduce the amount of pesticides and fertilizers applied in the orchard system. The incorporation of plant bioregulators into orchard systems reduces excess vegetative growth and habitat for insect pests while increasing spray efficiency and so reduces the amount of pesticides needed to control a pest. 2. How serious is the problem? Why does it matter? Reduction in the use of pesticides is a national priority. Pesticide application and pruning account for over 50% of the cost of fruit production in the eastern U.S. where conditions favor vegetative growth and heavy pest pressure. The loss of key insecticides in 2001 limits grower ability to control insect pests and increases the risk of significant fruit loss and increases the cost of production. More efficient cultural management practices which integrate the soil and climatic conditions of the region into the production system will improve production efficiency, lower pesticide use and production costs, and increase competitiveness and profitability to fruit growers. Without continued improvement in cultural management practices, tree fruit growers throughout the eastern U.S. will cease to be competitive in a global market and the industry will be lost to foreign imports. 3. How does it relate to the national Program(s) and National Program Component(s) to which it has been assigned? The research addresses the critical issue of National Programs 304 (Crop Protection and Quarantine) and 305 (Crop Production) for food safety and reduced chemical and mineral release from agricultural activities. The research relates to traditional agriculture as well as small farm and organic agriculture. 4. What was your most significant accomplishment this past year? A. Single Most Significant Accomplishment during FY 2002: The glassy-winged sharpshooter insect (GWSS) was recently introduced into California, vectoring Pierce's disease, and killing 40% of the grape vines in the Temecula Valley over the past three years; it is now spreading to the lower San Joaquin Valley and threatening the California wine and table grape industry. Three large replicated field trials were established in table grape in Kern Co., by Appalachian Fruit Research Station scientists from Kearneysville, WV in collaboration with the University of California Extension Service, in grower fields to test the efficacy of particle film technology and conventional insecticides in preventing GWSS infestation and oviposition in grape. Grapes treated with particle film showed significant reductions in Pierce's disease vectored by the GWSS and citrus crops treated with particle film treatments in the fall had significantly reduced over-wintering GWSS. The particle film, 'Surround WP', is now part of a county-wide IPM program in Kern Co. for GWSS control in grape that is being implemented by the California Department of Food and Agriculture. B. Other Significant Accomplishment(s) if any: (1) Although the plum curculio is considered to be a key pest of apple in eastern North America, peach and plum in the southern United States, and cherry and blueberry throughout the east, there are no effective monitoring methods to detect its entry into fruit orchards to better time insecticide sprays to control this pest, nor is there an alternative control method. We evaluated current monitoring practices at the Appalachian Fruit Research Station and in grower fields to determine why the current technology is ineffective in apple orchards and identified new plant volatiles, in collaboration with Dr. Aijun Zhang, Research Chemist at ARS-Beltsville, MD, that are more effective attractants for the insect traps in order to develop more effective monitoring techniques. We identified visual and olfactory competition between trap attractants and the orchard itself as a significant factor affecting current monitoring practices. The potential impact of this project will be to provide apple growers with an effective monitoring technique based on behavioral and chemical ecology that could eventually be developed into an alternative control strategy for plum curculio. (2) Apple surface blemishes caused by insects, disease, or nutrient imbalances, reduce apple quality and value, with the result that affected apples we then culled or sold at a reduced price. In field studies at AFRS, stink bugs were observed feeding on developing apple fruit creating damage to the fruit that resembled cork spot, a physiological disorder related to calcium deficiency; therefore to establish a cause-effect relationship, stink bugs were caged on apple branches and half the trees had calcium applied at the maximum recommended rate and the other half of the trees had no calcium added. Apples that were caged with stink bugs had significantly more cork spot damage than uncaged branches, the presence of a feeding puncture was found in each of the cork spot damage sites, and the addition of calcium had no effect on the amount of cork spot in caged or uncaged branches. The correct identification of stink bugs as the cause of at least some of the cork spot problems on apple will give growers the ability to prevent this type of damage and can result in a reduction in the amount of calcium that is applied when it is not necessary. (3) The use of flowering plants to attract natural enemies of insect pests in orchards has been investigated at a number of laboratories, but data on which flower species are best at attracting natural enemies is lacking. At three research plots at the Appalachian Fruit Research Station, fifteen species of flowering plants were evaluated for their attractiveness to beneficial insects and pest insects with field observations, and the effectiveness of biological control was measured with aphids and tufted apple budmoth caterpillars placed on potted apple trees that were then placed in the plots of flowers. Buckwheat, dill, and marigold were selected as the best plants to use for increasing the amount of biological control in orchards because of their high attractiveness to insect natural enemies, and the combination of the three plants will provide flowers over most of the summer months when pest control is needed. Selection of these plants for use in orchards will give growers and researchers specific recommendations based on research data as to which flowering plants are best for attracting biological control resulting in decreased insecticide usage. (4) There is a need to identify new chemistries with insecticidal activity. Under a CRADA with AVA Chemical Ventures and Applied Power Concepts, the effect of sugar esters that varied in sugar or fatty acid compositions on the dosage-mortality and time-mortality relationships was studied at the Appalachian Fruit Research Station for several different insect species to establish how insecticidal activity was affected by sugar ester chemistry. The research demonstrated that insecticidal activity of sugar esters changes when making alterations in polyol esters. A joint patent was issued for ARS and Applied Power Concepts entitled: "Polyol ester insecticides and method of synthesis" (Patent No. 6,419,941) which will provide a new low toxicity insecticidal chemistry. (5) There are new insecticides entering the market and effective pest control requires the use of many types without a thorough understanding of their interaction on the pest complex and the plant. Several types of insecticides were mixed with 'Surround' Crop Protectant, an insect repellant, and their efficacy evaluated on pests of apple and pear at the Appalachian Fruit Research Station. Combining 'Surround' with insecticides increased leafhopper control over all materials alone and for other pest species; 'Surround' did not interfere with the insecticidal activity of several classes of insecticides. These results demonstrate that pests not effectively repelled by 'Surround' can be treated with insecticide generally at the recommended rate or in some cases, with lower rates. (6) Tree fruit crops develop shaded areas due to the extensive canopy and reduced light will decrease photosynthesis, yield and quality. A particle film material, 'Surround-WP' developed under a CRADA with Engelhard Corp., was applied directly to apple trees and to the driveway between trees to reflect photosynthetically active radiation (PAR) into the canopy at the Appalachian Fruit Research Station. Tree photosynthesis, yield, and quality were increased as a result of the PAR reflection in apple trees. 'Surround-WP' was developed under a CRADA with Engelhard and provides a new tool to improve grower returns and productivity while reducing the environmental impact of agriculture on the environment. (7) Shade cast by an apple tree's own foliage and from cloud cover reduces fruit bud initiation and lowers fruit quality. Field studies were conducted over a four-year period at the Appalachian Fruit Research Station to examine the effect of partial and continuous shade on growth and fruiting in apple. Results demonstrated that three to six hours of shade applied between 0800 hours and 1330 hours daily had a greater effect on shoot growth and fruit yields than did shade applied for the same length of time daily between 1330 and 2000 hours. These studies could influence future pruning and tree orientation practices, and illustrates to apple growers the need for good pruning practices that result in open, light accessible canopies. (8) Large amounts of poultry manure and bedding (litter) are generated in the eastern U.S. and applied to farm land as a waste management practice to control weeds and to provide essential plant nutrients; however, excess nutrients in soil runoff can cause undesirable changes in aquatic communities. In laboratory, greenhouse, and field experiments at the Appalachian Fruit Research Station, in collaboration with scientists from Beltsville, MD and College Park, PA, ARS units (Adler and Sikora) and from the Univ. of Maryland and Hood College (Preusch and Ferrier), nitrogen and phosphorus release into soil and subsequent plant uptake from composted litter was determined. Composted litter had lower nitrogen release into the soil than fresh (uncomposted) litter, but water- extractable phosphorus, which represents phosphorus that can cause oxygen depravation, was not reduced by composting. The results provide needed information on how to manage poultry manure and compost as an organic fertilizer in orchards in order to minimize environmental contamination with nitrogen and phosphorus. (9) The plant bioregulator, prohexadione-calcium (ApogeeRG), has demonstrated its ability to suppress the shoot blight stage of fire blight, a very destructive disease in young apple trees, but at the label rates it causes too much growth suppression in young non-bearing trees, thus increasing their time needed to fill the allotted orchard space. Together with Dr. John Norelli, plant pathologist, at AFRS, two highly susceptible fire blight apple cultivars were treated at the Appalachian Fruit Research Station with recommended and low-dose sprays of prohexadione-calcium, inoculated with the fire blight bacteria, and then examined for growth and shoot blight. Low-dose prohexadione-calcium sprays suppressed shoot blight on 'Gala' apple but not 'York Imperial'; however, season-long shoot growth for low-dose trees did not differ from that of trees sprayed at the higher recommended rate. The results suggest that low-dose prohexadione-calcium sprays may provide apple growers with an effective shoot blight suppressant for some cultivars, but the use of a low-dose spray will adversely reduce shoot growth needed by young trees. (10) Prohexadione-calcium is an anti-gibberellin (GA) plant bioregulator that effectively controls excessive shoot growth in apple by suppressing the conversion of inactive GA20 to active GA1; however, the material is sometimes applied to trees that are also treated with a gibberellin spray to reduce fruit cracking. Studies were carried out at the Appalachian Fruit Research Station over several seasons to examine the potential for antagonistic effects from the application of these two plant bioregulators to the same tree. Prohexadione-calcium applied to suppress shoot growth increased fruit cracking on the highly desirable 'Stayman' apple and reduced the crack suppressing capability of the recommended GA- based plant bioregulator spray. The research led to a label restriction warning on the product prohexadione-calcium (ApogeeRG). (11) The susceptibility of new apple cultivars to the common white rot fungus Botryosphaeria dothidea is an important criterion in the commercial acceptance of these cultivars in the mid-Atlantic and southeastern U.S. Scientists from the Appalachian Fruit Research Station, in cooperation with Dr. Alan Biggs at the West Virginia University Fruit Research Center, developed methods to study susceptibility of 21 new and two established apple cultivars to the white rot fungus in controlled field and laboratory inoculation studies. The results from the two-year study permitted the selected apple cultivars to be classified from most susceptible to least susceptible to the white rot organism. This information is aiding apple growers and extension fruit specialists in selecting the most disease resistant apple cultivars for planting. (12) When plants assimilate carbon dioxide from the atmosphere through photosynthesis, the carbon is partitioned to roots, shoots, and fruit; yet we lack a detailed understanding of the mechanisms and factors controlling the carbon balance. A long-term carbon balance of apple trees was modeled for the Kearneysville, WV area and compared to similar carbon balances for Geneva, NY, Wenatchee, WA, and New Zealand in collaboration with Dr. Alan Lakso, Cornell University. This study will provide insight into environmental factors limiting apple production in the Mid-Atlantic States. C. Significant Activities that Support Special Target Populations. None 5. Describe your major accomplishments over the life of the project, including their predicted or actual impact? (1) Alternative pest control and improved production methods are needed because the national tree fruit industry is facing the loss of key insecticides in 2003 by FQPA (Food Quality Protection Act) and global competition is limiting markets. A particle film barrier for insects, sunburn protection, and heat stress reduction was invented by ARS scientists, commercialized by Engelhard Corp. as the brand name 'Surround', and applied to more than 100,000 acres of tree fruit in 2001, and 300,000 in 2002, primarily for pear psylla control and sunburn reduction. 'Surround' proved to be highly effective in controlling pear psylla and reduced losses from sunburn by 50%. Particle film technology will become a major new tool for sustainable horticultural plant production and crop protection. (2) Excessive vegetative growth in fruit trees reduces yield, fruit quality and interferes with pesticide coverage and pest control. The present and the previous CRIS project made significant contributions to identifying uses and developing knowledge that was critical for registration of a plant growth regulator, Apogee. Apogee controls vegetative growth in apple and pear and therefore reduces the amount of pesticide required for effective pest control. Apogee could be used by 70% of the apple growers and is the most significant advance in the practical control of the destructive shoot blight stage of the fire blight disease in apple in more than 40 years. Apogee is a tool that will aid all apple and pear growers and make the U.S. fruit industry more globally competitive and sustainable by helping reduce the amount of applied pesticides and improving fruit productivity and quality. (3) Herbicides are widely used to control weeds, which reduce fruit yield and quality, but social, ecological, and legal issues may impact their use in the future. The impact of long-term herbicide application on herbicide residues in soil, weed community dynamics and on growth of newly planted fruit trees was investigated. Despite 15 years of long- term use, no build-up of diuron, simazine, or terbacil residues in the soil was measured and the herbicides had no adverse effects on the young fruit trees. These results indicate that diuron, simazine, or tebacil are safe herbicides for use in orchard systems, but long-term use of terbacil may inhibit growth of newly-planted peach trees. (4) Apple color is a key factor in fruit quality. Studies were established to evaluate the potential of reflective groundcovers to increase light scatter into the apple tree in order to improve apple color development. The research demonstrated that plastic reflective groundcover material can enhance red color in selected apple cultivars when applied to the orchard floor at least six weeks before harvest and canopy form and/or training system can influence apple color development in the Appalachian growing region. The reflective groundcover materials are now commercially available for use by tree fruit growers and the data developed provides support for their use. (5) Tree fruit production systems that are sustainable and utilize biological control of pests make the most efficient use of the natural resources. Predatory and beneficial insect populations increased when orchard habitat diversity was increased by planting various ground covers beneath fruit trees, applying composted chicken manure to the orchard floor for weed control and nutrient supply, and interspersing different species of fruit trees within the orchard. Peach harvest of high quality low-spray peaches grown with flowering ground cover plants, mating disruption for oriental fruit moth, and reduced insecticides was similar to a conventionally managed check orchard in total yield, fruit size, and amount of insect damage. 6. What do you expect to accomplish, year by year, over the next 3 years? FY 2003: 1. Data collection is completed on the effectiveness of an insect predator complex to control rosy apple aphid. A decision can be made whether the level of biological control is as stable and cost effective as the use of conventional insecticides. This information will be transferred to extension pest management professionals for implementation. 2. Field evaluations are completed on the use of light-reflecting particle film materials as herbicides. The reliability of weed control and the amount of light reflected in the plant canopy are assessed and this information is used by the CRADA partner (Engelhard Corp.) to make a decision to commercialize a formulation. If commercialized, the weed control product will meet National Organic Standards. 3. The key sugar ester chemistries with insecticidal activity and polyol ester blends that are most effective in insect mortality are identified. This information will assist the CRADA partner (AVA Chemical) in determining which chemistries should be focused upon for further field testing, commercialization, and registration as an insecticide. In addition, the information gained from this CRADA will provide a basis for identifying new areas of sugar ester chemistry to pursue. 4. Data collection will be completed related to how different formulation additives affect the durability, insect control efficacy, and horticultural aspects of kaolin-based particle films. This information will be used by the CRADA partner to determine if significant formulation changes are needed and can result in new particle film products for high rainfall or windy areas of U.S. FY 2004: 1. Data collection is completed on new plant growth regulators used for fruit thinning and the information is used by industry to support label recommendations and EPA registration. 2. Evaluation of NE-183 apple cultivar evaluation is completed and information on pest susceptibility and fruit quality is published. This information is used by nurseries and growers to aid in selection of new apple cultivars for commercial plantings. 3. Field evaluations are completed on the use of hydrophobic formulations as barriers to freezing under radiation frost conditions. The reliability and degree of freeze protection are assessed and this information is used by the CRADA partner (Engelhard Corp.) to make a decision to commercialize a formulation. FY 2005: 1. Data collection is completed on training, fruit quality, yield, and performance of newly released cultivars of pillar peach. Guidelines are published on planting systems to guide extension agents and growers. 2. Guidelines on flowering species and planting design to enhance biological control of insect pests in apple orchards are completed. The information is published and used by pest management professionals to advice growers. 3. Evaluation of synthetic host fruit order blend formulations in the field and growth chambers that attract plum curculio and dogwood borer is completed. Patents are submitted for volatile compounds that out-compete natural sources of host odor in conjunction with insect traps and monitoring strategies for plum curculio and dogwood borer. 4. Data collection is completed for four years on the how the particle film ('Surround WP') treatments affect the transmission of Pierce's disease by the glassy-winged sharpshooter in grape. These data will be used to develop recommendations on the use 'Surround WP' for prevention of Pierce's disease. 5. New knowledge will be developed of hormone and morphological relationships in unique growth habits of peach. This will identify biochemical sites for selection and manipulation by breeders and horticulturists who are developing fruit trees with specific vegetative traits, such as branch frequency, canopy size, and cropping for high density orchards. 7. What technologies have been transferred and to whom? When is the technology likely to become available to the end user (industry, farmer other scientist)? What are the constraints, if known, to the adoption durability of the technology? A. Sugar Esters: A sugar ester material was EPA registered in 2002 as an insecticide. Licensing of ARS patents is being negotiated. B. Particle Film Technology. Particle film technology is available nationwide as 'Surround-WP Crop Protectant'. It is used for insect control in organic and conventional production systems to control a range of insect pests and to reduce heat stress and sunburn damage. C. Prohexadione-calcium. Information on the use of prohexadione-calcium (ApogeeRG) was presented to scientists, technical representatives, and fruit growers. The information and science is immediately available to end-users and includes information on reducing vegetative growth of fruit trees, decreased pesticide application and reductions in fire blight incidence. D. Technology Transfer through formal meetings (1) Oral presentation - Eastern Apple Production - Where are we and where is the future? 2002 Southeastern Apple growers Conference, Asheville, NC. (2) Oral presentation - Maintaining consistent apple production. 2002 Southeastern Apple growers Conference, Asheville, NC. (3) Oral presentation - Fruit production in West Virginia. 2002 WVU Country Roads Scholars Tour, Kearneysville, WV. (4) Oral presentation - What do we know about Apogee use on apples, 2002 WVU Winter Fruit School, Kearneysville and Romney, WV. (5) Invited Speaker. 2002. In-Depth Grower Meetings. Agriculture Research and Extension Center, Virginia Tech. New Developments in Plum Curculio Monitoring and Management. Winchester VA. (6) Invited Speaker. 2002. Virginia Polytechnic Institute and State University. Department of Entomology. Identification of attractive cues used in host finding: behaviorally based monitoring and management for the plum curculio. Blacksburg VA. (7) Invited Speaker. 2002. University of Maryland. Department of Entomology. Identification of attractive cues used in host finding: behaviorally based monitoring and management for the plum curculio. College Park MD. (8) Paper Presentation. 2001. Entomological Society of America, Annual Meeting. Influence of olfactory and visual competition on plum curculio responses to traps baited with synthetic fruit volatiles and pheromone. San Diego, CA. (9) Presentation of stink bug results to New York fruit growers at Upper Hudson/Champlain Valley Commercial Tree-fruit School, and the Hudson Valley Commercial Tree-fruit School.2001. "Is it or isn't it" Stink bug injury or cork spot?" (10) Presentation to North Central Entomological Society of America meeting, and workshop for Michigan Organic Tree Fruit Producers. 2002. Also, interviewed on use of flowering plants and compost mulches for Michigan Farm Radio Network. "Companion plant approach to organic tree fruit production". (11) Presentation of Effects of Transgenic Plants on Non-target Organisms. 2002. 15th Biennial International Plant Resistance to Insects Workshop, Feb. 24-27. Baltimore, MD. (12) Paper Presentation of Particle Film Technology for Control of Glassy-winged Sharpshooter. 2001. Pierce's Disease Research Symposium, December 5-7, San Diego, CA. (13) Paper Presentation of Particle Film Technology for Sharpshooter and Leafhopper Control in Grape. 2001. 77th Cumberland-Shenandoah Fruit Workers Conference, Nov. 15-16, Winchester, VA. (14) Paper Presentation of Particle Film Technology for Control of Glassy-winged Sharpshooter. 2001. Annual Entomological Society of America Meeting, December 10-14, San Diego, CA. (15) Paper Presentation of Herbicide effects of essential oils. Proceedings of the Plant Growth Regulation Society of America. 2001 Meeting of the Plant Growth Regulation Society of America. Miami Beach, FL. (16) Paper Presentation of Yield of peach trees grown with different competition and pruning. 2001 Meeting of the American Society of Horticultural Science. Sacramento, CA (17) Paper Presentation of Two year response of apple and peach trees to scoring and restriction of trunks. 2001 Cumberland-Shenandoah Fruit Workers Conference. Winchester, VA. (18) Paper Presentation of Integrated pest management aspects of organic mulch in apple orchards. 2001. Entomological Society of America. San Diego, CA. (19) Invited Presentation of Effects of Long Term Herbicide Use on the Orchard Floor and Growth of Young Fruit Trees at the 2001 Mid-Atlantic Fruit and Vegetable Convention, Hershey, PA. 8. List your most important publications and presentations, and articles written about your work (NOTE: this does not replace your review publications which are listed below) (1) Naegly, S. Monitoring in the mid-Atlantic. 2002. American Fruit Grower. v.122(5). p.29. (2) Teas, H. Area wide organic pest management project. Basin Business Journal. June 28, 2002. (3) Puterka, G., Glenn, D.M., Luvisi, D. New tool for sharpshooter control. California Grower. Nov. 2001. p.8-9.

Impacts
(N/A)

Publications

  • Janisiewicz, W.J., Tworkoski, T.J., Kurtzman, C.P. Biocontrol potential of Metchnikowia pulcherrima strains against blue mold of apple. Phytopathology. 2001. v. 91. p. 1098-1108.
  • Tworkoski, T.J., Scorza, R.. Root and shoot characteristics of peach trees with different growth habits. Journal of American Society of Horticultural Science. 2001. v. 126. p. 785-790.
  • Tworkoski, T. J., Glenn, D.M. Yield, shoot and root growth, and physiological responses of mature peach trees to grass competition. HortScience. 2001. v. 36. p. 214-1218.
  • Tworkoski, T., Miller, S.S. Apple and peach orchard establishment following multi-year use of diruon, simazine, and terbacil. HortScience. 2001. v. 36(7). p. 1211-1213.
  • Tworkoski, T.J., Glenn, D.M., Puterka, G.J. Response of bean to applications of hydrophobic mineral particles. Canadian Journal of Plant Science. 2002. v. 82. p. 217-219.
  • Glenn, D.M., Prado, E., Erez, A., McFerson, J., Puterka, G.J. A reflective, processed-kaolin particle film affects fruit temperature, radiation reflection, and solar injury in apple. Journal of American Society of Horticultural Science. 2002. v. 127. p. 188-193.
  • Wisniewski, M., Glenn, D.M., Fuller, M. Use of a hydrophobic particle film as a barrier to extrinsic ice nucleation in tomato plants. Journal of American Society of Horticultural Science. 2002. v. 127. p. 358-364.
  • Miller, S.S. Prohexadione-calcium controls vegetative shoot growth in apple. Journal Tree Fruit Production. 2002. v. 3(1). p. 11-28.


Progress 10/01/00 to 09/30/01

Outputs
1. What major problem or issue is being resolved and how are you resolving it? The national tree fruit industry is facing the loss of key insecticides in 2001 by the Food Quality Protection Act ( FQPA), in addition to continual development of insect resistance to insecticides. Increased nitrate levels and the presence of agrochemicals in drinking water and waterways demonstrate the need to efficiently manage nutrients, water, and the application of agrichemicals. Concerns for human health and the environment have led to reduced pesticide and fertilizer use through the development of alternative pest and fertilizer practices in integrated orchard management systems without a reduction in orchard productivity. Alternative insect control products have been developed, such as the particle film, 'Surround', and sugar esters. New methods of orchard management enhance biological control of orchard pests, improve fruit quality and yield, reduce weed competition, and reduce the amount of pesticides and fertilizers applied in he orchard system. The incorporation of plant bioregulators into orchard systems reduces excess vegetative growth and habitat for insect pests while increasing spray efficiency and so reduces the amount of pesticides needed to control a pest. Research is being conducted on the: (1) ecology of insects involved in biological control, including insect behavior, (2) mechanisms of insect control with particle films, sugar esters and other materials for insect control, (3) role of heat, water and nutrient stress in plant productivity and fruit quality, (4) mechanism of vegetative growth control and inducing fruit buds, and (5) role of training and orchard floor management methods to affect light and temperature within the canopy. 2. How serious is the problem? Why does it matter? Reduction in the use of pesticides is a national priority. Pesticide application and pruning account for over 50% of the cost of fruit production in the eastern U.S. where conditions favor vegetative growth and heavy pest pressure. The loss of key insecticides in 2001 limits grower ability to control insect pests and increases the risk of significant fruit loss and increases the cost of production. More efficient cultural management practices which integrate the soil and climatic conditions of the region into the production system will improve production efficiency, lower pesticide use and production costs, and increase competitiveness and profitability to fruit growers. Without continued improvement in cultural management practices, tree fruit growers throughout the eastern U.S. will cease to be competitive in a global market and the industry will be lost to foreign imports. 3. How does it relate to the National Program(s) and National Component(s)? The research addresses the critical issue of National Programs 304 (Crop Protection and Quarantine) and 305 (Crop Production) for food safety and reduced chemical and mineral release from agricultural activities. The research relates to traditional agriculture as well as small farm and organic agriculture. 4. What were the most significant accomplishments this past year? A. Single most Significant Accomplishment during FY2001. The Glassy-winged sharpshooter insect (GWSS) was recently introduced into California, vectoring Pierce's disease, killing 40% of the grape vines in the Temecula Valley over the past two years, now spreading to the lower San Joaquin Valley and threatening the California wine and table grape industry. Three large replicated field trials were established in table grape in Kern Co., by AFRS scientists from Kearneysville, WV (in collaboration with the University of California Extension Service) to test the efficacy of particle film technology and conventional insecticides in preventing GWSS infestation and oviposition in grape. Three applications of 'Surround WP' were found to be more effective than six applications of conventional insecticides. This research, plus other reserach done in Temecula Valley in FY2000, established 'Surround WP' as an effective material against GWSS with unique properties of repellency and deterrence in feeding and oviposition, therefore 'Surround WP' became a cornerstone in the IPM program to control GWSS, called "The Area-wide Management of GWSS, A Pilot Study" which is considered the model for GWSS management in California. B. Other Significant Accomplishment(s), if any: 1. Research on reduced insecticide use in apple production was initiated to provide alternative management options to farmers for the expected loss of available materials, and to develop more environmentally-friendly apple pest management systems. Apples were grown with flowering ground cover plants, mating disruption for oriental fruit moth, one spray of a conventional insecticide and several selective insecticide sprays. Apple harvest was similar to a conventionally-managed check orchard in yield and amount of insect damage. These results show that commercial apple production with reduced use of insecticides is possible with existing technologies. 2. Peaches are produced on seedling-rooted trees planted at low tree densities, which contributes to low yields per hectare. Two new peach tree forms, pillar and upright, were trained to a central leader or multiple leader system to determine their horticultural characteristics (growth and yield) when planted at various densities. Training these new forms required significant time compared to standard form peach trees, and pruning encouraged excessive vegetative growth, which may be counterproductive; however, early yields and fruit quality were very encouraging and demonstrated the potential for achieving high density peach plantings with seedling rooted trees. This large field experiment has led to new studies that will examine the effect of no pruning and no fertilizer on growth of pillar and upright peach tree forms. 3. Organic farmers cannot use most synthetic herbicides and weed infestations result in costly crop losses. Laboratory and greenhouse experiments were initiated to determine the herbicidal effect of plant-derived oils and identify the active ingredient in one oil with herbicide activity. The essential oil of cinnamon had high herbicidal activity and eugenol (2-Methoxy -4-(2-propenyl)phenol) was determined to be the largest component (84%). Essential oils are extracted from plants and thus may be useful as a "natural product herbicide" for organic farming systems. 4. Plum curculio is an important pest of both pome and stone fruit in eastern North America and it was necessary to determine if currently available monitoring systems were adequately detecting dispersal into orchards. The impact of visual and olfactory stimuli provided by apple, both on the ability of plum curculio to perceive synthetic fruit volatiles and pheromonal baits and on captures of plum curculio in monitoring traps was investigated using mark-release-recapture studies with field-collected plum curculios in an open field and within an orchard. Although attraction to olfactory stimuli provided by synthetic fruit volatiles and pheromonal baits did occur, significant differences in captures in open field versus orchard were recorded indicating that better attractants are needed to effectively monitor plum curculio populations entering orchards. Although attraction to these synthetic attractants is present and currently available traps do capture individuals, new avenues to improve their effectiveness will be evaluated. 5. There is a need to identify new chemistries with insecticidal activity. Under a CRADA with AVA Chemical Ventures and Applied Power Concepts, the effect of sugar esters that varied in sugar or fatty acid compositions on the dosage-mortality and time-mortality relationships was studied for several different insect species to establish how insecticidal activity was affected by sugar ester chemistry. The research demonstrated that insecticidal activity of sugar esters changes when making alterations in fatty acid or sugar components. A joint patent between the ARS and Applied Power Concepts entitled: "Improved polyol ester insecticides and method of synthesis" was allowed by the US Patent and Trade Office, which will provide a new low toxicity insecticidal chemistry. 6. Heat, water and ultraviolet radiation stress reduce the productivity of tree fruit crops. A particle film material, 'Surround-WP', developed under a CRADA with Engelhard Corp., was applied to apple trees to reflect heat and ultraviolet radiation. Tree photosynthesis and yield were increased as a result of reducing environmental stress and the particle film material was also effective in reducing sunburn damage on apples. 'Surround-WP' was developed under a CRADA with Engelhard and provides a new tool to improve grower returns and productivity. 7. Apple trees often produce excess vegetative growth that reduces cropping, increases pest problems, and increases cultural management costs. Controlling this unwanted vegetation is a major problem for apple growers. Research has shown that a plant growth regulator, prohexadione-calcium, is very effective in reducing shoot growth, but response may be affected by the pH of the spray solution. Field studies with prohexadione-calcium applied at various solution pH levels from acidic (pH 4.0) to basic (pH 9.0) indicated response was not affected in this range. This information will aid commercial fruit growers in the use of the compound registered as Apogee Growth Regulator. 8. There is significant interest from apple growers and consumers to develop new apple cultivars, but there is little information concerning the horticultural characteristics and fruit quality of some recently released varieties. A replicated planting of 22 new apple cultivars was planted at AFRS in 1995 and with the cooperation of the pathologist and entomologist from the West Virginia University (WVU) Experiment Station, the horticultu- ral characteristics (growth, yield, etc.) & disease susceptibility of these cultivars was identified for this growing region. Ten cultivars were initially identified as having commercial potential for this region based 4-year's evaluation of tree growth, yield, fruit quality, and disease susceptibility and the group was reduced to 4 cultivars with the fifth year data set. This information will assist nurserymen & apple growers in selecting & planting newer apple varieties & could hasten the availability of these selections to consumers on a wide scale. 9. Peach tree size can be managed by pruning & by growing sod beneath the trees, but the interactive effects of these cultural practices on yield are not well characterized. Field studies were established in 1993 with two pruning strategies & three sod-row widths. From 1995 to 2001, trees grown with light pruning yielded 29 to 58% more marketable fruit than heavy- pruned trees in the widest sod-rows, & yield efficiency was increased by light pruning, particularly in the wisest sod-rows. This information will assist researchers in evaluating sod management as a potential cultural practice to control tree size, & if adopted by growers, will reduce pruning costs, while protecting the soil from erosion. 10. Management of tree size & excess vegetative growth is a significant ex- pense to orchardists. In May 2000, 4 treatments were installed 20cm agove the graft union of apple & peach trees to control vegetative growth: (1) the trunk was cut to the secondary xylem with a hacksaw blade (score); (2) the trunk was completely encircled by a clamp with a 2cm band width tightened to 10 inch pounds (band); (3) the trunk was firmly encircled with waterproof tape (tape); & (4) untreated control. By June, scoring inhibited shoot elongation nearly 50% in apply & 38% in peach, but band & tape treat- ments did not inhibit shoot elongation. Scoring can reduce vegetative growth & improve light penetration into the tree which improves fruit quality. The reduction in vegetative growth decreases pruning time & the grower's labor costs. 11. A 2-year field experiment was concluded to determine if composted poultry litter (CPL) applied as mulch (at two rates) in an apple orchard affected weed control & the efficacy of 2 herbicides (diuron & terbacil). High rates of CPL provided better control of weeds than low rates; CPL did not improve or hinder herbicide efficacy, & perennial weeds dominated sites that were not herbicide-treated. CPL can be used to control many annual weeds, but these studies demonstrate to growers that perennial weeds will establish unless other weed control measures are used. 12. Early spring frosts cause millions of dollars in crop loss each year. Many crop species will cool below freezing temperatures without ice forma- tion if water is not present on the plant surface. A water-repelling parti- cle film that prevents water from contacting plant surface was developed. Results found it effective in preventing freeze injury in laboratory & & field studies. Additional work is needed to develop spray & formulation technology to effectively apply this product in commercial agriculture. C. Significant Accomplishments/Activities that Support Special Target Popu- lations: Small farming enterprises benefit from new tree fruit production practices. The development of'Surround WP Crop Protectant'is a cost-effec- tive, organically certified insect & disease control system with improved worker safety that provides pest control generally equivalent to conven- tional pesticides. Orchard floor management systems that enhance biological control with flowering plants & compost additions reduce the use of pesti- cides, worker exposure to toxic materials, & production costs, while main- taining high productivity. Small farms improve productivity by controlling excessive vegetative growth by using Apogee in apple production & sod management in peach production. New herbicide & insecticide chemistries are in development with reduced human toxicity that will improve small farmer worker safety. New apple & peach cultivares are in development. 5. Describe the major accomplishments over the life of the project including their predicted or actual impact. Alternative pest control and improved production methods are needed because the national tree fruit industry is facing the loss of key insecticides in 2001 by the Food Quality Protection Act (FQPA) and global competition is limiting markets. A particle film barrier for insects, sunburn protection, and heat stress reduction was invented by ARS scientists, commercialized by Engelhard Corp. as the brand name 'Surround', and applied to more than 10,000 acres of tree fruit in 2000, and 100,000 in 2001, primarily for pear psylla control and sunburn reduction. 'Surround' proved to be highly effective in controlling pear psylla and reduced losses from sunburn by 50%. Particle film technology will become a major new tool for sustainable horticultural plant production and crop protection. Herbicides are widely used to control weeds, which reduce fruit yield and quality but social, ecological, and legal issues my impact their use in the future. The impact of long-term herbicide application on herbicide residues in soil, weed community dynamics and on growth of newly planted fruit trees was investigated. Despite 15 years of long-term use, no build-up of herbicide residues in the soil was measured and the herbicides had no adverse effects on the young fruit trees. These results indicate that diuron, simazine, or tebacil are safe herbicides for use in orchard systems. Excessive vegetative growth in fruit trees reduces yield, fruit quality and interferes with pesticide coverage and pest control. The present and the previous CRIS project made significant contributions to identifying uses and developing knowledge that was critical for registration of a plant growth regulator, Apogee. Apogee controls vegetative growth in apple and pear and therefore reduces the amount of pesticide required for effective pest control and is also the most significant advancement in fireblight control in 40 years. Apogee is a tool that will aid all apple and pear growers and make the U.S. fruit industry more globally competitive and sustainable by helping reduce the amount of applied pesticides and improving fruit productivity and quality. Apple color is a key factor in fruit quality. Studies were established to evaluate the potential of reflective groundcovers to increase light scatter into the apple tree in order to improve apple color development. The research demonstrated that plastic reflective groundcover material can enhance red color in selected apple cultivars when applied to the orchard floor at least six weeks before harvest and canopy form and/or training system can influence apple color development in the Appalachian growing region. The reflective groundcover materials are now commercially available for use by tree fruit growers and the data developed provides support for their use. Tree fruit production systems that are sustainable and utilize biological control of pests make the most efficient use of the natural resources. Predatory and beneficial insect populations increased when orchard habitat diversity was increased by planting various ground covers beneath fruit trees, applying composted chicken manure to the orchard floor for weed control and nutrient supply, and interspersing different species of fruit trees within the orchard. Total yield, fruit size, and amount of insect damage were similar in a peach orchard grown with flowering ground cover plants, mating disruption for orchard fruit moth, and reduced insecticides compared to a conventionally-managed orchard with a full input of pesticides. 6. What do you expect to accomplish, year by year, over the next 3 years? FY 2002. 1. Develop new knowledge to support registration of sugar ester material for insect control in a wide range of crops and particle film materials with disease control in tree fruit crops. 2. A particle delivery system will be developed that improves the efficiency of current agrochemicals and reduces pesticide use rates. 3. Complete the evaluation of 22 new apple cultivars. 4. Establish grower demonstration apple and peach orchards using organic production protocols incorporating flowering plants, composted manure, interplanting peach and apple, and reduced use of insecticides. 5. Initiate a study to evaluate different placement of flowering plants in the orchard to maximize biological control and minimize impact on yield. 6. Develop new information on the use of prohexadione-calcium in hard water and in young apple trees to reduce the incidence of fire blight without adverse effects on shoot growth needed for young trees. 7. Initiate new weed control studies that comply with USDA Organic Standards. 8. Complete assessment of new attractants for plum curculio based on preferences observed for different stone and pome fruit in the field and develop behaviorally based trapping devices. FY 2003. 1. Guidelines are developed for the management of groundcover species and alternative insect control methods to reduce insecticide use in peach and apple production. 2. New knowledge is generated on how biochemical changes in roots affect root morphology and function. 3. New knowledge is developed on the pruning, fertilization and productivity of pillar form peach trees. 4. Report the horticultural characterisitics for 20 new apple cultivars planted in 1999 as part of the NE-183 project. 5. Identify specific compounds comprising the most attractive fruit odor sources, test synthetic equivalents and refine both style and placement of traps. FY 2004. 1. New weed control techniques are developed using low rates of herbicides and non-synthetic chemical techniques. 2. Guidelines are developed for the management of pillar peach types. 3. New knowledge is developed to support registration of plant growth regulators to reduce alternate bearing in apple cultivars. 4. A model of carbon partitioning in apple trees is used to develop fruit thinning strategies to improve fruit quality. 5. Develop orchard plan to incorporate flowering plants and extra-floral nectar producing peach trees for use in ecologically based pest management system to be implemented in grower orchards. 6. New knowledge is developed on the effect of intermittent shade on flowering, fruiting, tree growth and fruit quality and the effect of day/night temperature on flowering and apple tree carbohydrate levels. 7. Initiate field testing of new synthetic host fruit odor blends intended to outcompete natural sources of host odor in conjunction with our newly developed traps. 7. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end user (industry, farmer, other scientists)? What are the constraints if known, to the adoption & durability of the technology product? A. Sugar Esters: 1. Sucrose octanoate is being evaluated by University of Florida and University of California researchers as a potential control agent against the glassy-winged sharpshooter, an important pest of the grape and almond industry, especially in California. Registration of a sugar ester material is likely in 2002. B. Particle Film Technology: 1. Various particle film formulations were transferred to ARS scientists to determine its potential against the Formosan Termite, a major structural pest. 2. Various particle film formulations were transferred to ARS scientists to determine its potential against stored grain pests. 3. Particle film technology is being evaluated by the Glassy Winged Sharp Shooter (GWSS) Task Force to evaluate its potential for control of GWSS and prevention of Pierce's disease in California which has become a devastating pest to the table grape and wine industry. An ARS scientist located at AFRS Kearneysville, WV was assigned to the GWSS Task Force. 4. Particle Film technology has been transferred to university and extension researchers across the country in other commodities to evaluate its potential against thrips and diseases in peanut, aphids and stress in cotton, whitefly in tomato, japanese beetle in blueberry, thrips in lemon, and rose chafer in peach. 5. Particle film technology was transferred to ARS scientists to evaluate its potential against the new introduced pest, Asian Citrus Psyllid and Citrus root weevil. 6. Particle film technology was transferred to ARS scientists to evaluate its potential against pests of vegetables. 7. Particle film technology was transferred to the Washington State Tree Fruit Research Commission to evaluate its potential for insect control as well as horticultural benefits. 8. Particle film technology is available nationwide as Engelhard Corp's product 'Surround-WP' Crop Protectant. C. Technology Transfer Through Formal Meetings: 1. Technology Transfer of Particle Film Technology. (a) Presented research on particle film technology at the Minnesota Apple Growers Association Meeting, January 2001. Lacrosse, WI. (b) Presented 'Particle Film Technology for GWSS Control', GWSS Research Conference. November 2000. Riverside, CA. (c) 7th International Symposium on Orchard and Plantation Systems. "Improving temperature, light and water regimes in apple trees by kaolin particle film application". Newlson, New Zealand, Jan-Feb 2000. 2. Presentation of paper, "Ecologically Sustainable Approach to Organic Tree Fruit Production." and "Efficacy of Kaolin- and Sulfur-based Particle Films to Control Insects and Diseases in Apples" at First National Organic Tree Fruit Symposium. May-Jun 2001. Grand Junction, CO. 3. Transferred technology on the use of plant growth regulators to fruit growers, company tech. reps, and industry support personnel at the following meetings: Cumberland-Shenandoah Fruit Workers Conference. November 16-17, 2000. Winchester, VA. 4. 2001 Northeast Plant Growth Regulator Working Group Conference. March 13-15, 2001. Wilkes-Barre, PA. 5. Penn State Extension Fruit School on Plant Growth Regulators. March 6, 2001. Biglerville, PA. 6. Performance of new apple cultivars was presented to fruit growers at the Virginia Polytechnical Institute (VPI) In-depth Spring Fruit School. May 9, 2001. Winchester, VA. Provided recommendations for the for most promising apple cultivars to plant. 7. Transferred information on the training and performance of pillar, upright and standard peach trees to research scientist and extension personnel at the 5thInternational Peach Symposium, July 8-11, 2001. Davis, CA. 8. List your most important publications in the popular press (no abstracts) and presentations to non-scientific organizations and articles written about your work (NOTE: this does not replace your peer-reviewed publications which are listed below) 1. Multi-purpose Products Tested by Geraldine Warner, Good Fruit Grower. May 2001. p. 18. 2. Particle Film Proving its Worth by Lisa Heacox, Fruit Grower. May 2001. v.121. p. 26. 3. Whitewashing Agriculture, Agricultural Research, Nov 2000. p.14-17. 4. Biggs, A.R., Miller, S. S. 2000. Relative susceptibility to bitter rot of selected apple cultivars from NE-183 field trials. The Mountaineer Grower No. 562. p. 6-15.

Impacts
(N/A)

Publications

  • Tworkoski, T.J., Benassi, T.E., Takeda, F. The effect of nitrogen on stolon and ramet growth in four genotypes of Fragaria chiloensis L. Scientia Horticulturae. 2000. v. 1553. p. 1-10.
  • Glenn, D.M., Wisniewski, M., Puterka, G.J., Sekutowski, D. Method for enhanced supercooling of plants to provide frost protection. 2001. U.S. Patent US06235683.
  • Glenn, D.M., Puterka, G.J., Drake, S., Unruh, T.R., Knight, A.L., Baherle, P., Prado, E., Baugher, T. Particle film application influences apple leaf physiology, fruit yield and fruit productivity. 2001. Journal of American Society for Horticulture Science. v. 126. p. 175-181.
  • Glenn, D.M., Scorza, R., Bassett, C. Physiological and morphological traits associated with increased water use efficiency in the willow-leaf peach. 2000. HortScience. v. 35. p. 1241-1243.
  • Knight, A.L., Christianson, B.A., Unruh, T.R., Puterka, G., Glenn, D.M. Impacts of seasonal kaolin particle films on apple pest management. Canadian Entomologist. 2001. v. 133. p. 413-428.
  • Brown, M.W., Schmitt, J.J. Seasonal and diurnal dynamics of beneficial insect populations in apple orchards under different management intensity. Environmental Entomology. 2001. v. 32(2). p. 415-424.
  • Miller, S.S. Some indirect effects of Apogee on apple trees. Proceedings of Cumberland Shenandoah Fruit Workers Conference. 2000. v. 76. p. 226-229.
  • Miller S.S., Scorza, R. Preliminary results and observations in training pillar and upright form peach trees. Proceedings Cumberland-Shenandoah Fruit Workers Conference. 2000. v. 76. p. 306-315.
  • Biggs, A.R., Miller, S.S. Relative susceptibility of selected apple cultivars to Colletotrichum acutatum. Plant Disease. 2001. v.85(6). p. 657-660.
  • Tworkoski, T.J. Response of Potted Peach Trees to Pruning and Grass Competition. HortScience. 2000. v. 35(7). p. 1209-1212.


Progress 10/01/99 to 09/30/00

Outputs
1. What major problem or issue is being resolved and how are you resolving it? The national tree fruit industry is facing the loss of key insecticides in 2001 by FQPA (Food Quality Protection Act), in addition to continual development of insect resistance to insecticides. Increased nitrate levels and the presence of agrichemicals in drinking water and waterways demonstrate the need to efficiently manage nutrients, water, and the application of agrichemicals. Concerns for human health and the environment have led to reduced pesticide and fertilizer use through the development of alternative pest and fertilizer practices in integrated orchard management systems without a reduction in orchard productivity. Alternative insect control products have been developed, such as the particle film, Surround, and sugar esters. New methods of orchard management enhance biological control of orchard pests, improve fruit quality and yield, reduce weed competition, and reduce the amount of pesticides and fertilizers applied in the orchard system. The incorporation of plant bioregulators into orchard systems reduces excess vegetative growth and habitat for insect pests while increasing spray efficiency and so reduces the amount of pesticides needed to control a pest. Basic research is being conducted in the: 1) ecology of insect biological control, 2) mechanisms of insect control with particle films, sugar esters and other materials for insect control, 3) role of heat, water and nutrient stress in plant productivity and fruit quality, 4) mechanism of vegetative growth control and inducing fruit buds, and 5) role of training and orchard floor management methods to affect light and temperature within the canopy. 2. How serious is the problem? Why does it matter? Reduction in the use of pesticides is a national priority. Pesticide application and pruning account for over 50% of the cost of fruit production in the eastern U.S. where conditions favor vegetative growth and heavy pest pressure. The loss of key insecticides in 2001 limits grower ability to control insect pests and increases the risk of significant fruit loss and increases the cost of production. More efficient cultural management practices which integrate the soil and climatic conditions of the region into the production system will improve production efficiency, lower pesticide use and production costs, and increase competitiveness and profitability to fruit growers. Without continued improvement in cultural management practices, tree fruit growers throughout the eastern U.S. will cease to be competitive in a global market and the industry will be lost to foreign imports. 3. How does it relate to the National Program(s) and National Component(s)? The research addresses the critical issue of National Program 304-Crop Protection and Quarantine, and National Program 305-Crop Production, for food safety and reduced chemical and mineral release from agricultural activities. The research relates to traditional agriculture as well as small farm and organic agriculture. 4. What were the most significant accomplishments this past year? A. Single Most Significant Accomplishment during FY2000 Year: Research on reduced insecticide use in peach production was initiated to provide alternative management options to farmers for the expected loss of available insecticides, and to develop more environmentally friendly peach pest management. Peaches were protected from insect damage with flowering ground cover plants that increased predatory insects in the orchard, mating disruption for oriental fruit moth, one spray of a conventional insecticide and several sprays with biological controlling agent- Bacillus thuringiensis (Bt). Peach harvest was similar to a conventionally managed check orchard in total yield, fruit size, and amount of insect damage. These results show that commercial peach production with reduced use of insecticides is possible with existing technologies. B. Other Significant Accomplishments: 1. There was a need to identify new sugar ester chemistries that had enhanced insecticidal activity. Under a Cooperative Research and Development Agreement (CRADA) the effect of sugar esters that varied in sugar or fatty acid compositions mortality of several different insect species was studied to establish how insecticidal activity was affected by sugar ester chemistry. The research demonstrated that insecticidal activity of sugar esters changes when making alterations in fatty acid or sugar components. A joint patent (filed in February 2000 and entitled: "Improved polyol ester insecticides and method of synthesis") will provide a new low toxicity insecticidal chemistry. 2. Heat and water stress reduces the productivity of tree fruit crops. A particle film material, developed under a CRADA was applied to apple trees to reflect heat. Tree photosynthesis and yield were increased as a result of reducing heat stress and the particle film material was also effective in reducing sunburn damage on apples. This new technology improves grower returns and productivity. C. Significant Accomplishments/Activities that Support Special Target Populations: 1. There is a need to develop new apple cultivars to increase grower competitiveness. A replicated planting of 22 new apple cultivars was established at the Appalachian Fruit Research Station (AFRS), and with the cooperation of the pathologist and entomologist from the WVU Experiment Station, the horticultural characteristics (growth, yield, etc.) and disease susceptibility of these cultivars was identified for this growing region. Ten cultivars were identified as having commercial potential for this region based on four years evaluation of tree growth, yield, fruit quality, and disease susceptibility. This information will assist nurserymen and apple growers in selecting and planting newer apple varieties and could hasten the availability of these selections to consumers on a wide scale. 2. Disposal of waste from animal production is a significant problem and organic fruit growers need alternatives to synthetic chemicals for weed control. In collaboration with other ARS scientists (Leetown, WV and Beltsville, MD) and scientists from the University of Maryland and Hood College, MD composted poultry litter was applied at AFRS as a mulch in a peach orchard to determine its potential for weed control, insect control and to reduce water pollution. Weeds were controlled into the second but not the third year after compost mulch application whereas the number and activity of insect predators increased. Composted poultry litter can be applied in orchards as a nutrient source and to suppress weeds and contribute to control of insect pests. 5. Describe the major accomplishments over the life of the project including their predicted or actual impact. 1. Alternative pest control and improved production methods are needed because the national tree fruit industry is facing the loss of key insecticides in 2001 by the FQPA and global competition is limiting markets. A particle film barrier for insects, sunburn protection, and heat stress reduction was invented by ARS scientists, commercialized as the brand name 'Surround' and applied to more than 10,000 acres of tree fruit in 2000, primarily for pear psylla control and sunburn reduction. 'Surround' proved to be highly effective in controlling pear psylla and reduced losses from sunburn by 50%. Particle film technology will become a major new tool for sustainable horticultural plant production and crop protection. 2. Herbicides are widely used to control weeds, which reduce fruit yield and quality but social, ecological, and legal issues may impact their use in the future. The impact of long-term herbicide application on herbicide residues in soil, weed community dynamics and on growth of newly planted fruit trees was investigated. Despite 15 years of, no build-up of herbicide residues in the soil was measured and the herbicides had no adverse effects on the young fruit trees. These results indicate that diuron or terbacil are safe herbicides for use in orchard systems. 3. Excessive vegetative growth in fruit trees reduces yield, fruit quality and interferes with pesticide coverage and pest control. The present and the previous CRIS project made significant contributions in identifying uses and developing knowledge that was critical for registration of a plant growth regulator, Apogee. Apogee controls vegetative growth in apple and pear and reduces the number and extent of fire blight strikes in apple and pear, while reducing the amount of pesticide required for effective pest control. New plant growth regulators are a tool that will make the U.S. fruit industry more globally competitive and sustainable by helping reduce the amount of applied pesticides and improving fruit productivity and quality. 4. Apple color is a key factor in fruit quality. Studies were established to evaluate the potential of reflective groundcovers to increase light scatter into the apple tree in order to improve apple color development. The research demonstrated that plastic reflective groundcover material can enhance red color in selected apple cultivars when applied to the orchard floor at least 6 weeks before harvest and canopy form and/or training system can influence apple color development in the Appalachian growing region. The reflective groundcover materials are now commercially available for use by tree fruit growers and the data developed provides support for their use. 5. Tree fruit production systems that are sustainable and utilize biological control of pests make the most efficient use of the natural resources. Long-term studies were established that increased the diversity of vegetation and ecological habitats in tree fruit orchards. Predatory and beneficial insect populations increased when orchard habitat diversity was increased by planting various ground covers beneath fruit trees. Orchard systems that utilize ground covers will have increased biological control of pests and this will reduce the amount of pesticide required to produce high quality fruit. 6. What do you expect to accomplish, year by year, over the next 3 years? FY 2001: 1. New knowledge to support registration of sugar ester material for insect control in a wide range of crops will become available. 2. New knowledge to support registration of particle film materials with disease control in tree fruit crops will become available. 3. A particle delivery system will be developed that improves the efficiency of current agrochemicals and reduces use rates. FY 2002: 1. Guidelines are developed for the management of groundcover species and alternative insect control methods to reduce insecticide use in peach and apple production. 2. New knowledge is generated on how biochemical changes in root affect root morphology and function. 3. The Maryblyt model is improved to include timing of new materials that control fireblight, the most serious disease of apples and pears in the U.S. FY 2003: 1. New weed control techniques are developed using low rates of herbicides and non-chemical techniques 2. Guidelines are developed for the management of pillar peach types which are suitable for high density, highly productive peach orchards. 3. New knowledge is developed to support registration of plant growth regulators to reduce alternate bearing in apple cultivars. 4. A model of carbon partitioning in apple trees is used to develop fruit thinning strategies to improve fruit quality. 5. A model of powdery mildew, a major disease in fruit crops, is developed and validation studies initiated. 7. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end user (industry, farmer, other scientists)? What are the constraints if known, to the adoption & durability of the technology product? Science or technology was transferred in the areas of sugar esters, particle film technology and plant growth regulators. 1. Sugar Esters: Sucrose octanoate is being evaluated by University of Florida, and University of California researchers as a potential control agent against the glassy-winged sharpshooter, an important pest of the grape and almond industry especially in California. Registration of a sugar ester material is likely in 2001. 2. Particle Film Technology: A. Various particle film formulations were transferred to ARS scientists to determine its potential against the Formosan Termite, stored grain pests Asian Citrus Psyllid in citrus, and pests in vegetables. The Washington State Tree Fruit Research Commission evaluates the Particle Film efficacy against insects and for horticultural benefits. B. Particle film technology is being evaluated by the Glassy Winged Sharp Shooter (GWSS) Task Force to evaluate its potential for control of GWSS and prevention of Pierce's disease in California which has become a devastating pest to the grape and wine industry. C. Particle Film technology has been transferred to University and Extension researchers across the country to evaluate its potential against thrips and diseases in peanut, aphids and stress in cotton, whitefly in tomato, Japanese beetle in blueberry, thrips in lemon, and rose chafer in peach. D. Particle film technology is available nationwide as Engelhard Corp.'s product 'Surround-WP'. E. A symposium was held at the XXI International Entomology Congress in Iguazu Falls, Brazil entitled: Advances in particle film technology for agriculture. August 20-26, 2000 during which CRIS scientists transferred the newest information on the use of particle film technology for controlling insects and to mitigate deleterious effect of environmental stresses. 3. Plant Growth Regulators: A. Information on the use of Apogee growth regulator and was transferred to scientists, chemical company reps, and industry field consultants at the Apogee Research Summit, Ft. Lauderdale, FL, Feb 19-21, 2000 and to fruit growers, company technical representatives and industry support personnel at the following meetings: York/Lancaster County Tree Fruit Growers Educational Meeting. February 23, 2000. (approximately 50 in attendance); WV Winter Tree Fruit School. Eastern Panhandle Session. February 14, 2000. (approximately 80 in attendance); WV Winter Tree Fruit School. Hampshire County Session. February 23, 2000. (approximately 25 in attendance). B. Transferred technology on the use of plant growth regulators in general and apple thinners specifically at Berkeley-Jefferson County Fruit Growers Meetings. April 4, 2000 and May 2, 2000 (approximately 20 in attendance at each meeting); transferred information on the use of plant growth regulators to scientists and chemical industry field representatives (35 attendees) at the 2000 Northeast Plant Growth regulator Working Group Conference, Wilkes-Barre, PA, March 7-9, 2000. C. Transferred technology on the control of Stayman apple cracking and 20 new apple cultivars to fruit growers and industry personnel at the North Jersey Commercial Fruit Growers Meeting, 3/10/00, approximately 80 in attendance. 8. List your most important publications in the popular press (no abstracts) and presentations to non-scientific organizations and articles written about your work (NOTE: this does not replace your peer-reviewed publications which are listed below) 1. Particle films and softer Integrated Pest Management (IPM) for pears. Good Fruit Grower. 2000. July. v.51. p.29-31. 2. Particle film technology. Presented to BioDynamic Conference. September 2000. Charles Town, WV. 3. "Biology and management of woolly apple aphid", "Particle Films for Orchard Pest Control", "Horticultural benefits of particle film technology in apple production" at the Winter Tree Fruit School. Kearneysville, WV. March 15, 2000. Romney, WV. March 23, 2000. 4. "Effects of residues of diuron, simazine, and terbacil on newly plante apple and peach trees".- regarding carryover effects of residual herbicides on newly planted fruit trees. "Particle films for control of apple and pear pests" and "Horticultural benefits of particle films in apple production"-regarding particle film technology; "Orchard diversity, reduced insecticides and fruit quality: preliminary data"-regarding ground covers. Papers presented to scientists at the 75th Cumberland-Shenandoah Fruit Workers Conference. 1999. Winchester, VA. 5. "Weed control and mineralization of nitrogen and phosphorus from compo poultry mulch in a West Virginia peach orchard". Paper presented to scientists at the Northeastern Weed Science Society on weed control and nutrient availability from poultry litter compost mulch applications in fruit orchards. 1999. Baltimore, MD. 6. "Weed Suppression and N and P Mineralization in an Orchard Mulched wit Composted Poultry Litter". Paper presented to scientists at the American Society for Horticultural Science on weed control and nutrient availability from poultry litter compost mulch applications in fruit orchards. 2000. Orlando, FL. 7. Papers presented to scientists at the Entomological Society of America International workshop on Aphidophaga and Ecological Society of America on biological control of aphids on apple, Atlanta, GA; Bromont, Quebec; Spokane, WA. 1999 and 2000. 8. "Root Characteristics of Peach Trees with Different Shoot Growth Habit Paper presented to scientists at the American Society for Horticultural Science Conference on peach root and shoot development. 2000. Orlando, FL

Impacts
(N/A)

Publications

  • Puterka, G.J., Glenn, D.M., Sekutowski, D.G., Unruh, T.R., Jones, S.K. Progress toward liquid formulations of particle films for insect and disease control in pear. 2000. Environmental. Entomology. v.29. p.329-339.
  • Unruh, T.R., Knight, A.L., Upton, J., Glenn, D.M., Puterka, G.J. Particle films for suppression of the codling moth (Lepidoptera:Tortricidae) in apple and pear orchards. 2000. Journal of Economic Entomology. v.93. p.737-743.
  • Knight, A.L., Unruh, R.R., Christianson, B.A., Puterka, G.J., Glenn, D.M. Effects of a kaolin-based particle film on obliquebanded leafroller (Lepidoptera: Tortricidae). 2000. Journal of Economic Entomology. p.744-749.
  • Puterka, G.J., Glenn, D.M., Sekutowski, D.G. Method for protecting surfaces from arthropod infestation. 2000. U.S. Patent 6,027,740.
  • Sekutowski, D.G., Puterka, G.J., Glenn, D.M. Aqueous dispersion of a particulate solid having a hydrophobic outer surface and films produced thereby. 2000. U.S. Patent 6,060,521.
  • Glenn, D.M., Sekutowski, D.G., Puterka, G.J. Method for preventing physiological disorders without diminishing photosynthesis. 2000. U.S. Patent 6,069,112.
  • Puterka, G. J. Fungal Pathogens for arthropod pest control in orchard systems: mycoinsecticidal approach for pear psylla control. 1999. BioControl. v.44. p.183-210.
  • Tworkoski, T.J., Welker, W.V., Vass,G.D. Weed Community Changes Following Applications of Diuron, Simazine, and Terbacil. Weed Technology. 2000. v.14(1). p.191-196.
  • Tworkoski, T.J., Welker, W.V., Vass G.D. Soil Residues Following Repeat Applications of Diuron, Simazine, and Terbacil. Weed Technology. 2000. v.14(1). p.197-203.
  • Tworkoski, T.J., Miller, S.S. Effects of residues of diuron, simazine, and terbacil on newly planted apple and peach trees. Proceedings of the 75th Cumberland-Shenadoah Fruit Workers Conference. 1999. v.75.
  • Preusch, P.L., Tworkoski, T.J. Weed control and mineralization of nitrogen and phosphorus from composted poultry mulch in a West Virginia peach orchard. Proceedings of the Northeastern Weed Science Society. 2000. v.54. p.18-19.
  • Preusch, P.L., Tworkoski, T.J. Weed Suppression and N and P Mineralization in an Orchard Mulched with Composted Poultry Litter. HortScience. 2000. v.35(3). p.168.
  • Tworkoski, T.J., Scorza, R. Root Characteristics of Peach Trees with Different Shoot Growth Habits. HortScience. 2000. v.35 (3). p.169.
  • Miller, S.S. Yield and quality attributes of promising apple cultivars in West Virginia. Proceedings of 75th Cumberland-Shenandoah Fruit Workers Conference. 1999. 13 pages.
  • Greene, G.M., Miller, S.S. Impact of fruit bud variables on the return bloom and productivity efficiency of York Imperial apples. 2000. Pennsylvania Fruit News. v.80(2). p.37-38.
  • Yoder, K.S., Miller, S.S., Byers, R.E. Suppression of fireblight in apple shoots by prohexadione-calcium following experimental and natural inoculation. 1999. HortScience. v.34. p.1202-1204.
  • Miller, S.S., Greene II, G.M. Improving red color on apples with a reflective groundcover. 2000. HortScience. v.35(3): Abstract. p.437.
  • Miller, S.S. , Byers, R.E. Response of winter-injured peach trees to pruning. 2000. HortScience. v. 35(3). Abstract. p.437.
  • Miller, S.S., Brown, M.W. Book Review. Integrated Pest Management for Stone Fruits. 2000. HortTechnology. v.10. p.235-236.
  • Glenn, D.M. Analysis of trickle and pulse microsprinkler irrigation of processing apples. 1999. Journal of Tree Fruit Production. v.2. p.11-18.


Progress 01/01/99 to 09/30/99

Outputs
1. What major problem or issue is being resolved and how are you resolving it? The national tree fruit industry is facing losses of key insecticides in 2000 by FQPA (Food Quality Protection Act), in addition to continual development of insect resistance to insecticides. Increased nitrate levels and the presence of agrichemicals in drinking water demonstrate the need to efficiently manage nutrients, water, and the application of agrichemicals. Excess vegetative growth is a major problem as it increases losses from pest problems, reduces spray coverage, lowers yields, increases pruning costs, and in general, lowers production efficiency. Concerns for human health and the environment have led to reduced pesticide and fertilizer use through the development of alternative pest and fertilizer practices in integrated orchard management systems without a reduction in orchard productivity. Alternative insect control products have been developed, such as Surround and sugar esters. New methods of orchard management enhance biological control of orchard pests, improve fruit quality and yield, reduce weed competition, and reduce the amount of pesticides and fertilizers applied in the orchard system. The incorporation of plant bioregulators into orchard systems reduces excess vegetative growth and habitat for insect pests while increasing spray efficiency and so reduces the amount of pesticides needed to control a pest. Basic research is being conducted in the:1) ecology of biological control and mechanisms of insect control with particle films and sugar esters, 2) role of heat and water stress in plant productivity, 3) mechanism of size controlling rootstocks to reduce shoot growth and inducing fruit buds, and 4) role of training and orchard floor management methods to affect light and temperature within the canopy. 2. How serious is the problem? Why does it matter? Reduction in the use of pesticides is a national priority. Pesticide application and pruning account for over 50% of the cost of fruit production in the eastern U.S. where conditions favor vegetative growth and heavy pest pressure. The loss of key insecticides in 2000 limit grower ability to control insect pests with the risk of significant fruit loss or substantially higher costs of production. More efficient cultural management practices which integrate the soil and climatic conditions of the region into the production system will improve production efficiency, lower pesticide use and production costs, and increase competitiveness and returns to fruit growers. Without continued improvement in cultural management practices, tree fruit growers throughout the eastern U.S. will cease to be competitive and the industry will be lost. 3. How does it relate to the National Program(s) and National Component(s) to which it has been assigned? The research addresses the critical issue of food safety and reduced chemical and mineral release from agricultural usage. The research relates to traditional agriculture as well as small farm and organic agriculture. 4. What were the most significant accomplishments this past year? Surround, a particle film barrier for insects and a heat reflective material, was commercialized by Engelhard Corp. and over 1000 acres of tree fruit were commercially treated in 1999. New formulations were evaluated prior to commercialization. Developed data set and background information that led to successful classification of plant bioregulator PBR, prohexadione-calcium, by EPA as a "reduced risk" candidate chemical. Recognized an interaction between prohexadione-Ca and another commonly used PBR, ProVide, that has potential to reduce the activity of prohexadione-Ca when both materials are applied to the same tree. Documented that a second generation of plum curculio develops in West Virginia and new mid-summer monitoring and pest control must be developed. Following 15 years of herbicide application, no evidence of herbicide phytotoxic carryover of diuron, simazine, or tebacil was demonstrated. These results indicate that orchardists can replant in old orchard sites. New sugar ester formulations were identified that consistently controlled a wide range of soft-bodied insect pests. Composted poultry litter can be applied as a mulch in an orchard to provide nutrients and control weeds without excessive nutrient release. 5. Describe the major accomplishments over the life of the project including their predicted or actual impact. A new concept was invented, particle film technology, as a nontoxic insect control agents for pests of a broad range of agricultural and greenhouse crops. The behavioral effects these particle barriers had on a variety of orchard arthropod pests was studied and various particle types and formulations were evaluated. The particle films are white and reflect heat and so reduce heat and water stress. The reduction of heat stress increased plant productivity and fruit quality. This research was funded by a CRADA with Engelhard Corporation. The research on the entomological and horticultural effects was used to help Engelhard obtain EPA Experimental Use Permits to test particle film materials and in the eventual registration of three materials. This research also served as a basis for outlining uses, application rates, and pest control recommendations for use on various crops. One patent has been issued and 5 others have been filed on concepts that resulted from this research. A master label has been granted for use on 38 fruit, nut, and vegetable crops and their pests by the EPA in August 1998. Particle films gained strong EPA and industry support because they have low toxicity and are on the EPA list of materials that are generally regarded as safe (GRAS). Established the use of natural & synthetic sugar-esters as a new nontoxic pesticide technology for orchard insect pest control. The research resulted in identifying sugar-esters as excellent agents for control of pear psylla and aphids, and provided new information on dose-mortality and time-mortality relationships, and residual activity, that were essential to the understanding of the fundamental properties of this compound. Field trials at various locations in the U.S. to determine the effective sugar ester concentrations for pear psylla control and efficacy against the various life stages of this pest. The significance of this technology for orchard pest control, as well as in other crops, has resulted in the establishment of a CRADA with AVA Chemical Technologies. This research led to the Identification of a sugar-ester that AVA has synthesized that is superior in formulation characteristics to the earlier synthetic sugar-esters. Sugar-esters are a new pesticide class that offers low toxicity to mammals and is environmentally benign, yet, very effective against various insects. These materials are similar in action to soaps, but could be a far more economical alternative to conventional insecticidal soaps. EPA registration of a sugar ester insecticide is expected for the 2000 growing season. Demonstrated the utility of peach trees in apple orchards for biological control. Biological control must be enhanced if pesticides are reduced and early season control is especially difficult when relying on immigrating biological control organisms. An orchard with apple and peach trees was monitored for pest and beneficial insects. In May, when many apple pestsare becoming established, lady beetles (aphid predators) were found to be abundant on apple trees in the orchard inter-planted with peaches but absent in an orchard with only apple. This demonstrates the utility of planting some peach trees (using widely spaced columnar peach trees, not necessarily a fully inter-planted system) in an apple orchard to attract biological control organisms into the orchard for the development of new planting systems to enhance biological control in orchards. The success of ground cover plantings together with the addition of some peaches being planted into apple orchards will add to the biological control in orchards and will be used in revising orchard planting programs for the purpose of enhancing biological control. Demonstrated the growth controlling capacity of the gibberellin biosynthesis inhibitor, prohexadione calcium (BAS125W). This new plant bioregulator can reduce shoot growth by 50% and canopy volume by 10% thus reducing tree row volume and pesticide spray volume per acre. Demonstrated that multiple sprays are more effective for growth suppression than a single large dose. Research showed the material has no adverse effects on fruit quality and is not a residual chemical. In addition, demonstrated that BAS125W could reduce the incidence and extent of fire blight in apple by 40% with timely sprays. Demonstrated that plastic reflective groundcover (rgc) material can enhance red color in selected apple cultivars when applied to the orchard floor at least 6 weeks before harvest. Studies showed that canopy form and/or training system can influence the response to rgc material in the Appalachian growing region. The rgc materials are now commercially available for use by tree fruit growers and the data developed provides support for their use. As part of a large regional project, demonstrated the growth and early production potential of 17 new apple cultivars. Identified fire blight susceptibility of these new cultivars and potential problems with alternate bearing. Developed organoleptic profiles of new apple cultivars for use by growers and consumers in making apple selections. This information will help growers make decisions on new plantings. At present there is significant interest in new apple cultivars but a lack of information to support specific selections. Shoot growth of peach trees can be managed by manipulating edaphic conditions such as root volume and soil fertility. Peach trees were planted with a split root design so that half the roots were not treated and the other half received one of four treatments: root volume restricted with polypropylene nonwoven fabric (FAB); fertilizer alone (FER); FAB+FER; and untreated control. Fabric restricted root growth in peach trees and reduced shoot elongation; but fertilizer applied near fabric increased root growth. The combination of fabric plus selected application of fertilizer may be used to regulate growth of peach trees. Root characteristics may play significant roles in regulating shoot growth while maintaining yield in high-density peach tree plantings. Analysis of whole root systems and of new root architecture was conducted with four genetically distinct peach tree growth forms. Root biomass, branching frequency, and distribution in soil differed among genotypes and indicated a physiological relationship between root and shoot morphology. Results suggest that characteristics of root growth and metabolism may be genetically selected or managed to control shoot growth, including excess vegetative growth. 6. What do you expect to accomplish, year by year, over the next 3 years? FY2000: Compositional changes in particle films and sugar esters will be synthesized and initial efficacy evaluations performed. (NP 304) Determine whether purple tansy is a good addition to the ground cover mix or if it contributes to plant bug damage, and if a problem, remove it from the system. Evaluate the contribution of ground covers and tree species to insect control. Identify the key predators that are enhanced by use of composted chicken manure; evaluate the potential for E. coli growth on compost (if positive, discontinue study). Refine trap design for plum curculio monitoring. Initiate N sampling in soil and plants and evaluate horticultural effects. Collect weed abundance data. (NP 304). Forecast, environmental and plant data will be collected and initial algorithms prepared for Maryblyt, bloom and maturity models. Field trials to evaluate pH adjuvants in particle films and PGR effects on fire blight will be established. (NP304) Evaluate effective rates & timing of PGR applications. Establish trials to determine if irrigation and nutrient management treatments are reducing the impact of ground covers on yield and quality. Establish root restriction studies and collect initial data on phytohormone and nitrogen movement. (NP 305) Whole tree canopy photosynthesis chambers will be built and monthly sampling completed for particle film treatments with 2 crop loads. Evaluate water use efficiency. Growth chamber and field studies on return bloom initiated. Mineral nutrition studies are initiated. (NP 305) Peach growth type study established and data collected on root and shoot architectural relationships. (NP 305) FY2001: Field trials will be established to test compositional changes in particle films and sugar esters. Laboratory tests of action mechanisms will be further tested. (NP 304) After two years of data on ground covers and inter-planting tree species, evaluate the success and refine ground cover management practices to improve system, discontinue inter-planting study if data do not support its use. Quantify the increase in predation on specific pests as a result of composted chicken manure. Describe host plant differences in behavior patterns for plum curculio. Continue N and horticultural evaluation. Collect weed abundance data. (NP 304) Continue environmental and plant data collection. Field test Maryblyt model. Alternative disease control field studies will continue. (NP 304) Evaluate interaction of PGR's with gibberellin based PGR's. Continue trials to determine if irrigation and nutrient management treatments are reducing the impact of ground covers on yield and quality. Continue root restriction trials and phytohormone sampling. Establish root restriction effects on shoot growth. (NP 305). Whole tree canopy photosynthesis chambers will be used for monthly sampling of trees with particle films and various crop loads. Evaluate water use efficiency. Growth chamber and field studies related to return bloom are continued. N15 samples are collected. Mineral nutrition studies are continued. Data from Ca and NH4 studies is evaluated and a decision is made to continue this area of research. (NP 305) Peach growth type study continued. Early growth and physiological data are collected. Phytohormone concentrations are established. (NP 305). FY2002: Field and laboratory studies will continue to evaluate new compositional changes in particle films and sugar esters. Successful formulations will be selected. (NP 304) Evaluation of revisions made to ground cover management, plant different mix of ground cover species to improve the system. Continue economic data collection. Develop nutrient management recommendations for use of composted chicken manure in orchards. Begin plum curculio behavior modification in laboratory studies to develop monitoring and control options. Continue N and horticultural evaluation. Publish two-year data on weed abundance response to compost mulch. (NP 304) Develop model for bloom & fruit maturity for apple. Continue to collect environmental data for fire blight prediction. Determine accuracy for selected weather forecast services and use Maryblyt prediction program to assess probability of error. Effective disease control treatments will be selected and refinements evaluated. (NP 305) Publish results of PGR work. Continue trials to determine if irrigation & nutrient management treatments are reducing the impact of ground covers on yield and quality. Continue root restriction studies. Establish the interaction of root restriction and nutrient inputs on shoot growth and AUX and CK. (NP 305). Whole tree canopy photosynthesis chambers will be used for monthly sampling of trees with particle films and various crop loads. Water use efficiency studies are completed & manuscript prepared.The ability of trees treated with particle films to support greater fruit loads is accepted or rejected. Growth chamber and field studies related to return bloom are continued. N15 samples are collected. Effective treatments are identified and results published. Methods of tissue K are established and relationships between tissue K and fruit size are developed. (NP 305). Peach growth type and apple cultivar studies are continued. Early yield, growth and physiological data are collected. (NP 305) 7. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end user (industry, farmer, other scientists)? What are the constraints if known, to the adoption & durability of the technology product? During the past three years, 19 ARS researchers at 16 locations field-tested particle film materials for insect control and horticultural benefits. In addition, approximately 20 U.S. university scientists and 7 scientists from 6 foreign countries have also been involved in particle film tests. Grower testing of particle films has involved approximately 25 commercial growers. Sugar ester research has involved 6 ARS scientists at 6 locations and 6 university scientists. The customers include CRADA partners from industry, many scientists from various disciplines in the public and private sector, independent and industry producers. New formulations of Surround will be available nationally in 2000. Presentations of this technology were made at the Michigan State Horticulture Society annual meeting, Washington State Tree Fruit Commission, American Society for Horticultural Science, and the Entomological Science Society of America. A method for pruning winter-injured peach trees was transferred to approximately 350 fruit growers in Pennsylvania, West Virginia, Maryland and New Jersey at the 1999 Mid-Atlantic Fruit & Vegetable Convention, Hershey, PA. Technology can be adopted immediately. Information on the use of poly-type reflective groundcovers to improve color in apple was made available to over 400 growers and tree fruit industry persons at two meetings in PA - the 1999 Mid-Atlantic Fruit & Vegetable Convention, Hershey, PA and the 1999 Penn State University Tree Fruit Grower Field Day at Biglerville, PA. Technology, as we currently know it, can be used immediately by the industry. Information on new apple cultivars was transferred to approximately 120 growers from WV, MD, and VA at the 1999 combined Grower Twilight Field Meeting, Kearneysville, WV. Information is available to end-users. Information on the use of PBRs was transferred to scientists and chemical industry field representatives (37 attendees) at the 1999 Northeast Plant Growth Regulator Working Group Conference, Wilkes-Barre, PA. Information on groundcover research results were presented to Virginia fruit growers at the Winchester Agricultural Research an Education Center in Virginia. Information on nutrient release and weed control of poultry litters from different sources that were applied at different rates were presented to scientists and nutrient management specialists at the Annual Meeting of the Northeastern Branch of the American Society of Agronomy & Soil Science Society of America 11-14 July, 1999, University of Guelph, Guelph, Ontario, Canada. Information on grass competition effects on fruit production were presented to extension and other university scientists in the Appalachian Region and U.S. at the following meetings: -Cumberland-Shenandoah Fruit Workers Conference, Harpers Ferry, WV Nov. 1998. -Plant Growth Regulation Society of America, Costa Mesa, CA July 1999. -American Society for Horticultural Science, Minneapolis, MN Aug 1999. Information on the effects of root restriction on growth were presented to other scientists interested in fruit tree shoot management at the Plant Growth Regulation Society of America, Costa Mesa, CA July 1999 and the American Society for Horticultural Science, Minneapolis, MN Aug 1999. 8. List your most important non-peer reviewed publications and presentations to non-scientific organizations, and articles written about your work(NOTE: this does not replace your peer reviewed publications which are listed below). 1. Favorable Film. Oregon Farmer-Stockman, April 1999. 2. Kaolin Treatment KOs Some Problems. AgWorld. May 1999. 3. New Approach to Insect Control. Global Issues in Agricultural Research, Vol. 1, Issue, No. 3, January 25, 1998. 4. Feature Film: New Technology Creates Barrier. The Great Lakes Fruit Grower News. Vol. 37(3). 1998. 5. Pruning Winter-Injured Peach Trees. Pennsylvania Fruit News 79(4):46-50, 1999, by S.S. Miller and R.E. Byers. Talk delivered by S. S. Miller at the 199 Mid-Atlantic Fruit & Vegetable Convention, Hershey, PA. 6. Reflective Groundcovers for Improved Red Color in Apples- Results in the Mid-Atlantic. Pennsylvania Fruit News 79(4):55-63, 1999, by S. S. Miller and G.M. Greene. Talk delivered by S. S. Miller at the 199 Mid-Atlantic Fruit & Vegetable Convention, Hershey, PA. 7. Pruning Winter-Injured Peach Trees. Horticultural News 79(2):3-6,26-28, 1999, by S.S. Miller and R.E. Byers. 8. Talk at the Combined VA and WV Summer Twilight Field Fruit Grower Meeting, June 20, 1999 on performance of new apple cultivars.

Impacts
(N/A)

Publications

  • TWORKOSKI, T.J. and GLENN, D.M. 1999. Response of mature peach trees to grass competition. PGRSA Quarterly Abstract 27:(2).
  • TWORKOSKI, T.J. and GLENN, D.M. 1999. Response of mature peach trees to grass competition. HortScience Abstract 34(3):494.
  • DAW, T., TWORKOSKI, T.J. and GLENN, D.M. 1999. Root Restriction and fertilizer effects on young peach trees. HortScience Abstract 34(3): 494.
  • PREUSCH, P.L. and ADLER, P. 1999. Nitrogen mineralization and phosphorus ...litter. Amer Soc of Agronomy and Soil Science Society of Amer Abstract p. 37.
  • GLENN, D.M., PUTERKA, G.J., VAN DER ZWET, T., BYERS, R.J. and FELDHAKE, C. 1999. Hydrophobic Particle Films: A New Paradigm for Suppression of Arthropod Pests and Plant Diseases. J. Econ. Entomol. 92:759-771.
  • BROWN, M.W. 1999. Applying principles of community ecology to pest management in orchards. Agric. Ecocsys. and Environ. 73:103-106.
  • BROWN, M.W. and GLENN, D.M. 1999. Ground cover plants and selective insecticides as pest management tools in apple orchards. J. Econ. Entomol. 92:899-905.
  • VAN DER ZWET, T., HICKEY, K.D. and MILLER, S.S. 1999. Recovery of endophytic Erwinia amylovora from symptomless tissues of orchard apple trees. Phytopath. 89:S102.
  • TWORKOSKI, T.J.. 1998. Response of young peach trees to pruning and grass competition. Plant Growth Regulation Society of America Abstract. Pg. 159.