Source: UNIVERSITY OF FLORIDA submitted to
A NON-DORMANT SYSTEM FOR OFF-SEASON RASPBERRY PRODUCTION IN TROPICAL AND SUBTROPICAL CLIMATES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
SPECIAL GRANT
Reporting Frequency
Annual
Accession No.
0208209
Grant No.
2006-34135-17669
Project No.
FLA-HOS-04558
Proposal No.
2006-04771
Multistate No.
(N/A)
Program Code
AH
Project Start Date
Sep 15, 2006
Project End Date
Sep 14, 2009
Grant Year
2006
Project Director
Darnell, R. L.
Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611
Performing Department
HORTICULTURAL SCIENCE
Non Technical Summary
The production of temperate zone fruit crops in the tropics and subtropics is increasing as new cultural and management practices are developed that allow their adaptation. Raspberries (Rubus spp.) are small, precocious plants that yield high-priced fruit due to high consumer demand and the inability to store raspberry fruit long-term. Previous research with an annual raspberry production system in subtropical and tropical areas indicates that off-season (winter) raspberry production is achievable. However, yields obtained in this annual system have been marginal in terms of returns to the producer. This is likely due to the root loss - and resultant loss of carbohydrates to support fruit growth - when raspberry canes were removed from the nursery, placed into the annual production system, and fruited that same season. This project examines an alternative production system, using cane pruning and continuous fertilization to force new growth and avoid dormancy, potentially resulting in a multi-year winter production system in tropical and subtropical areas. Economic forecasts indicate that this type of system could result in high, net returns to growers. Additionally, this system would expand and diversify fruit products that have the potential for commercial production in tropical and subtropical areas of the U.S. Thus, the overall objective is to assess the feasibility of a raspberry production system that will increase crop diversity in the subtropics/tropics, and fill a market niche for winter raspberry production that will provide high returns to the growers.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20511231060100%
Knowledge Area
205 - Plant Management Systems;

Subject Of Investigation
1123 - Raspberry;

Field Of Science
1060 - Biology (whole systems);
Goals / Objectives
1. Evaluate a perennial, non-dormant, off-season raspberry production system in a subtropical (Florida) and tropical (Puerto Rico) climate by: a. determining the feasibility of pruning, leaf removal, and nitrogen applications in maintaining a perennial non-dormant production system. b. determining vegetative and reproductive growth and productivity of primocane and floricane fruiting raspberry in this system. One cultivar of each type will be evaluated in both locations. 2. Evaluate postharvest quality of fruit, including soluble solids, acidity, disease incidence, and storage ability. Although fruit quality information is available in traditional raspberry production systems, quality components may be modified in this proposed non-dormant system. 3. Determine the economic feasibility of this system by conducting an analysis of competitive potential.
Project Methods
To evaluate growth and productivity of raspberry, a two-bed planting system in a polyethylene tunnel will be used. Bareroot raspberry transplants will be obtained from northern U.S. nurseries and planted in the tunnel. The first year's experiment will be a 2x2x2 factorial consisting of two cultivars, two pruning intensities, and two defoliation intensities. The pruning intensities will be pruning all canes to ground level or pruning canes to 10 nodes. The two defoliations will consist of zero or complete defoliation of all canes. Additionally, nitrogen fertilization will be applied throughout the entire year, to maintain plant growth and avoid dormancy and the subsequent need for chilling. The experimental design will be a randomized complete block with 5 replications and 4-plant plots for each cultivar/pruning treatment. In the second and third years of the study, pruning and/or defoliation treatments will be modified, depending on results from previous years. The flowering period(s), harvest intervals, yield per harvest interval, and total yield will be determined for each cultivar/treatment plot. A subsample of fruit will be randomly selected within each harvest interval and individual fruit weight determined. Marketable fruit will be determined for each treatment by grading fruit for size, color, integrity, and presence or absence of insect and disease blemishes. Leaf tissue will be harvested periodically and nutrient analyses performed to determine any deficiencies or toxicities that might be occurring during the season. A similar raspberry production system will be established by the University of Puerto Rico in Lajas, PR, on the southern coast. The Lajas site will use the same cultivars, spacings, trellis system, and experimental design as described for Florida. In both locations (sub-tropical Florida and tropical Puerto Rico), the system will be evaluated for a minimum of two to three years. Postharvest fruit quality will be evaluation at both locations. Fruit samples will be evaluated for soluble solids and total acidity at harvest and after cold storage. Fruit water loss and decay will also be determined after storage. The economic feasibility of the proposed raspberry production system will be evaluated by conducting a three-stage analysis of competitive potential. Separate analyses for the Florida site and the Puerto Rico site will be conducted. The first stage will focus on estimation of production cost for a typical commercial operation. The second stage will be a comparison of estimated production cost with weekly FOB market prices reported by the USDA Agricultural Marketing Service during the pertinent seasonal production periods. Finally, an analysis of existing marketing mechanisms, linkages and infrastructure will be undertaken to ascertain the manner in which additional raspberry supplies will enter the market as well as determining which markets (e.g. wholesale, retail, institutional) provide the highest potential returns and probability of long-term competitive success.

Progress 09/15/06 to 09/14/09

Outputs
OUTPUTS: Crop diversification in tropical/subtropical climates is critical to meeting the need for new and changing market niches that are developing in these areas. Production of temperate crops in these regions during periods of high demand and limited supplies can result in high returns to growers. Previous research examined the feasibility of an annual production system for raspberry in tropical/subtropical climates. However, the economic analysis indicated that returns to the grower would be marginal in an annual system. Development of a perennial system for off-season production of raspberry fruit without the use of these highly toxic dormancy breaking chemicals can address important environmental issues associated with increasing crop diversity, while providing high returns for growers. Our previous research indicates that raspberry - a high cash crop - is amendable to soilless tunnel culture. The objective of the current research was to evaluate raspberry productivity in a perennial, non-dormant, off-season production system in subtropical (Florida) and tropical (Puerto Rico) climates. Two raspberry cultivars, a summer bearing and a fall bearing cultivar, were planted in raised beds in a polyethylene tunnel in December (Florida) or February (Puerto Rico). The non-dormant condition was maintained by combinations of year-round nitrogen fertilization, cane pruning, and defoliation. Flowering and fruiting were assessed the following season. The first fruiting season following planting, total fruit fresh weight/plant for the fall bearing cultivar averaged 793 g (FL) and 860 g (PR), while total fruit fresh weight/plant for the summer bearing cultivar averaged 31g (FL) and 98 g (PR). Following fruit harvest, the following pruning treatments were applied to both cultivars: 1) one-half of the plants were pruned to ground level and 3-5 new canes were allowed to grow or 2) one-half of the plants were pruned to 3-5 strong canes 10 nodes above ground level and all other canes were removed. Fall defoliation treatments were superimposed on the pruning treatments. One-half of the plants of each cultivar in each pruning treatment were defoliated in early (FL) or late November (PR). None of the fertilization, pruning, or defoliation treatments were successful in maintaining non-dormant, fruitful plants the following season. However, the high yields observed in the fall bearing cultivar the first year of planting suggests that the annual system previously examined may prove successful when fall bearing (rather than summer bearing) raspberry cultivars are used. PARTICIPANTS: Rebecca Darnell, PI. Supervised research, developed and implemented research plans. Jeff Williamson, co-PI. Aided in supervising research and developing research plans. Bryan Brunner, co-PI. Supervised the Puerto Rico planting. TARGET AUDIENCES: Target audiences are plant scientists and growers. Both oral and written presentations on this research have been given. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Off-season production of raspberry fruit without the use of highly toxic dormancy breaking chemicals can address important environmental issues associated with increasing crop diversity, while providing high returns to growers. However, a non-dormant perennial system does not appear to be a viable production system. The high first year yield obtained from planting chilled, short cane fall bearing cultivars suggests that an annual system using short cane, fall bearing cultivars - instead of the previously used long cane, summer bearing cultivars - may be a feasible production system. This warrants additional work.

Publications

  • Darnell, R.L., H.E. Alvarado,and J. G. Williamson. 2008. Root pruning effects on growth and yield of red raspberry. HortScience 43:681-684.


Progress 09/15/07 to 09/14/08

Outputs
OUTPUTS: Crop diversification in tropical/subtropical climates is critical to meeting the need for new and changing market niches that are developing in these areas. Production of temperate crops in these regions during periods of high demand and limited supplies can result in high returns to growers. Previous research examined the feasibility of an annual production system for raspberry in tropical/subtropical climates. However, the economic analysis indicated that returns to the grower would be marginal in an annual system. Development of a perennial system for off-season production of raspberry fruit without the use of these highly toxic dormancy breaking chemicals can address important environmental issues associated with increasing crop diversity, while providing high returns for growers. Our previous research indicates that raspberry - a high cash crop - is amendable to soilless tunnel culture. The objective of the current research is to evaluate raspberry productivity in a perennial, non-dormant, off-season production system in subtropical (Florida) and tropical (Puerto Rico) climates. Two raspberry cultivars, Lauren (summer bearing) and Caroline (fall bearing) were planted in raised beds in a polyethylene tunnel in Dec 2006 (Florida) or Feb 2007 (Puerto Rico). The experimental design was a RCB with 5 replications and 4 plants per plot. The non-dormant condition was maintained by combinations of year-round N fertilization, cane pruning, and defoliation. N was applied weekly from February through September 2007 at 200 mg/L and every other week from September 2007 through February 2008 at 200 mg/L, at which time weekly fertilizations resumed. Pruning treatments were imposed in mid-July 2007 in Forida and mid-September 2007 in Puerto Rico. Fall defoliation treatments were imposed the same season in early Nov (FL) or late Nov (PR). Flowering and fruiting were assessed in 2008. None of the treatments were successful in producing a viable crop, thus it appears that a non-dormant production system may not be a viable alternative for raspberry,as it has been for other fruit crops. PARTICIPANTS: Rebecca Darnell, PI. Supervises research, develops and implements research plans. Jeff Williamson, co-PI. Aids in supervising research and developing research plans. Bryan Brunner, co-PI. Supervises the Puerto Rico planting. TARGET AUDIENCES: Target audiences are plant scientists and growers. Both oral and written presentations on this research have been given. PROJECT MODIFICATIONS: Based on the poor performance of the perennial production system, we will return to the annual system, but make use of fall-bearing, short canes as our planting stock.

Impacts
Off-season production of raspberry fruit without the use of highly toxic dormancy breaking chemicals can address important environmental issues associated with increasing crop diversity, while providing high returns to growers. However, a non-dormant perennial system does not appear to be a viable production system. The high first year yield obtained from planting chilled, short cane Caroline (fall bearing) plants suggests that an annual system using short cane, fall bearing cultivars - instead of the previously used long cane, summer bearing cultivars - may be a feasible production system. This warrants additional work.

Publications

  • Darnell, R.L., H.E. Alvarado, and J.G. Williamson. 2008. Root pruning effects on growth and yield of red raspberry. HortScience 43:681-684.


Progress 09/15/06 to 09/14/07

Outputs
OUTPUTS: Crop diversification in tropical/subtropical climates is critical to meeting the need for new and changing market niches that are developing in these areas. Production of temperate crops in these regions during periods of high demand and limited supplies can result in high returns to growers. Previous research examined the feasibility of an annual production system for raspberry in tropical/subtropical climates. However, the economic analysis indicated that returns to the grower would be marginal in an annual system. Development of a perennial system for off-season production of raspberry fruit without the use of these highly toxic dormancy breaking chemicals can address important environmental issues associated with increasing crop diversity, while providing high returns for growers. Our previous research indicates that raspberry - a high cash crop - is amendable to soilless tunnel culture. The objective of the current research is to evaluate raspberry productivity in a perennial, non-dormant, off-season production system in subtropical (Florida) and tropical (Puerto Rico) climates. The non-dormant condition will be maintained by combinations of year-round N fertilization, cane pruning, and defoliation. Two raspberry cultivars, Lauren(summer bearing) and Caroline (fall bearing) were planted in raised beds in a polyethylene tunnel in Dec 2006 (Florida) or Feb 2007 (Puerto Rico). The experimental design was a RCB with 5 replications and 4 plants per plot. In both Florida and Puerto Rico, fruit harvest occurred from mid-May 2007 through mid-July. Total fruit fresh weight/plant for Caroline averaged 792.6 g (FL) and 859.9 g (PR), while total fruit fresh weight/plant for Lauren averaged 30.8 g (FL) and 97.9 g (PR). The increased yield for Caroline compared with Lauren in both plantings was due to increased fruit number in Caroline. Individual fruit size was greater in Lauren compared with Caroline. This was likely due to the decreased fruit load in that cultivar. Following fruit harvest, pruning treatments were applied to both cultivars. For Caroline the treatments consisted of 1) pruning one-half of the plants to ground level and allowing 3-5 new canes to grow and 2) pruning 3-5 strong canes on the other half of the plants to 10 nodes above ground level and removing all other canes as necessary. For Lauren the pruning treatments consisted of 1) pruning 3-5 strong canes on one-half of the plants to 10 nodes above ground level and 2) pruning 3-5 strong canes on the other half of the plants to 45 nodes above ground level. Pruning was done in mid-July in Florida and mid-Sept in Puerto Rico. Based on preliminary experiments from the previous year, fall defoliation treatments were superimposed on the pruning treatments. One-half of the plants of each cultivar in each pruning treatment were defoliated in early Nov 2007 (FL) or late Nov 2007 (PR). Effects of N fertilization, pruning, and defoliation on flowering and yield will be determined next spring. PARTICIPANTS: Rebecca Darnell, PI. Supervises research, develops and implements research plans. Jeff Williamson, co-PI. Aids in supervising research and developing research plans. Bryan Brunner, co-PI. Supervises the Puerto Rico planting. Horacio Alvarado, graduate student. Data collection and analysis for the Florida planting. TARGET AUDIENCES: Target audience is Horticultural scientists and growers. Efforts, in the form of oral and written presentations, will be forthcoming as more data are collected and analyzed

Impacts
Off-season production of raspberry fruit in a perennial system without the use of highly toxic dormancy breaking chemicals can address important environmental issues associated with increasing crop diversity, while providing high returns for growers. Although early in the research, it appears that fall bearing cultivars may have potential in this perennial system. It remains to be seen whether sufficient flower bud initiation will occur in our warm climates so that economical yields can be realized over multiple years.

Publications

  • Alvarado, H., R.L. Darnell, and J. Williamson. 2007. Root to shoot relations in an annualraspberry (Rubus idaeus L.) production system. HortScience 42:1559-1562.
  • Darnell, R.L., H. Alvarado,and J. Williamson. 2008. Root pruning effects on growth and yield of red raspberry. HortScience (accepted).