Progress 09/01/08 to 08/31/13

Outputs
Target Audience: Growers Tree fruit equipment manufacturers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Demonstrations and presentations were held at extension outreach, industry, and professional conferences, including the Washington State Horticultural Association, California Cling Peach Industry, Southeast Professional Fruit Workers, Mid-Atlantic Fruit and Vegetable, International Fruit Tree Association, Cherry Institute, NCW Stone Fruit Day and NE Agricultural and Biological Engineering meetings. Additional outreach efforts included trade journal articles, videos, posters, powerpoints, extension bulletins, posted at the project website (http://abe.psu.edu/scri). Undergraduate students, graduate students, growers, and equipment manufactuers participated in this project. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? A 6 column helix string arrangement compared to a 2 column 9 string arrangement increased thinning uniformity in 1 out of 3 trials. A string thinner modified to automatically adjust to canopy width and angle increased thinning efficacy and uniformity, and the thinner manufacturer plans to model a new thinner based on the Penn State prototype. Eight string thinners were purchased in 2010 by NE growers, and all reported reduced labor requirement. The drum shaker reduced crop load and follow-up hand thinning time significantly over a conventional hand thinning technique only when operating at 300 to 400 cycles per minute. Preliminary data suggest bark damage was less than obtained with previous prototypes, but damage was not eliminated, which is one of the ultimate goals. PSU and CMU graduate students tested ultrasonic and laser sensors to detect canopy shape and distance and automatically control the position of the string thinner. Based on blossom removal comparisons between automated and operator controlled string thinning, the automated systems were generally as good as a human at maintaining canopy engagement and may be economically viable methods of augmenting mechanical thinning. A video on this new technology is on-line at www.abe.psu.edu/scri. NE growers continued to purchase either Darwin (for planar tree canopies) or PT250 (for open vase-shaped canopies) string thinners and reported reduced labor requirement and improved fruit size. Socioeonomic survey results indicated that field trials to present evidence of increased management efficiency, improved fruit quality, and increased net income would result in a faster rate of adoption of new technologies. In peach thinning trials conducted in a season when bloom was 4 weeks early and there were three mornings when temperatures dropped to around 32 deg F, targeted flower removal was 30 to 40%, and crop load, follow-up hand thinning and percent fruit in higher value size categories were reduced in 3 of the 4 trials. Physiological drop in the control plots was significantly more than in the blossom thinned plots. Thinning of apple using the string thinner showed that as the number of strings increased, the level of thinning severity increased. Also, as spindle speed increased, the removal of the number of blossom clusters per limb cross-sectional area increased. The number of blossoms per spur declined as spindle speed increased. While increased spindle speed reduced cropload, injury to spur leaves limited any benefit of increased fruit size. Spindle speed of 300 rpm produced the largest gain in fruit weight of 28 g when compared to the control. However the most severe thinning treatments reduced yield by more than 50%. Fruit quality was generally enhanced with increased spindle speed. There was no relationship between spindle speed and return bloom. The string thinner consistently removed blossoms, but severe thinning treatments (240 - 300 rpm) resulted in high rates of spur removal and reduction in spur leaf area. Spindle speeds of 180 - 210 rpm provided the best overall thinning response and minimized injury to spur leaves. Damage to spur leaves negatively influenced fruit size, fruit retention, and fruit calcium. Growers continued to purchase either Darwin or PT250 string thinners and reported reduced labor requirement and improved fruit size. The manufacturer is automating the string thinner based on 2011 graduate student results with automated positioning and on-going selective thinner work on blossom imaging. Socioeonomic surveys conducted at a Mid-Atlantic producer convention indicated that 41% of participants were very likely to adopt peach thinning technologies; 33% were somewhat likely, 9% were unlikely, and 18% were already making changes. Selective thinning robot was developed and tested, to determine precision of positioning of the end effector. The vision system was integrated with the robot for on-the-fly blossom location and robot arm positioning. As a result of this project, over 60 commercial string thinners were sold in North America, with a sales value of close to $1M. Estimates of labor savings by commercial growers as a result of use of these units is estimated in the millions of dollars in the U.S.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Kon, T. M., J. R. Schupp, H. E. Winzeler and R. P. Marini. 2013. Influence of mechanical string thinning treatments on vegetative and reproductive tissues, fruit set, yield and fruit quality of apple. HortScience 48:40-46.
• Type: Journal Articles Status: Accepted Year Published: 2013 Citation: Kon, T. M. and J. R. Schupp. 2013. Hand-thinning tall spindle apple trees with the Equilifruit disc. HortTechnology 23: (HORTTECH-02575 accepted for publication July 9, 2013).
• Type: Other Status: Published Year Published: 2012 Citation: Auxt Baugher, T., J. Schupp, C. Lara, S. Prozo. 2012. Blossom thinning results in an early bloom season. Horticultural News 93(1):1-8.
• Type: Other Status: Published Year Published: 2012 Citation: Auxt Baugher, T. 2012. Mechanization research in the United States. Compact Fruit Tree 45(3):18-20.
• Type: Other Status: Published Year Published: 2013 Citation: Schupp, J., T. Auxt Baugher, E. Winzeler, T. Kon and M. Schupp. 2013. Labor efficient apple peach production. PA Fruit News 93(1):35-37.
• Type: Other Status: Awaiting Publication Year Published: 2013 Citation: Schupp, J., T. Auxt Baugher, P. Heinemann, E. Winzeler, T. Kon and M. Schupp. 2013. Labor efficient apple peach production. Compact Fruit.

Progress 09/01/11 to 08/31/12

Outputs
OUTPUTS: WA - Investigators established 2 apricot and 3 sweet cherry demonstration trials in commercial orchards. Replicated research was conducted in 1 sweet cherry handheld device trial and 1 multiyear apple trial. Apricot demonstration trials included both the Darwin string thinner and the INFACO hand held thinner. Sweet cherry demonstration work was limited to hand held devices. Year 2 activities of a 6 year apple trial were conducted. This trial was established to evaluate the Bonner string thinner, chemical thinning, and mechanical/chemical thinning on alternate years. A replicated trial in sweet cherry included the following treatments: handheld thinning device at bloom, manual hand thinning at bloom, green fruit thinning with clippers and untreated control. Field days and demonstrations were attended by 160 industry members, and meeting presentations were attended by 850 industry members. SC - South Carolina research focused on modifications to the design of the string thinner to make it adaptable to tree architectures in the Southeast. The blossom thinner was evaluated on 150 acres. A field day was attended by 100 growers. IL -- A fully functional robotic arm was developed to demonstrate thinning of fruit, with an innovative path planning algorithm that moves the end-effector along a branch to emulate a typical 5-8 pattern in an anthropomorphic manner. A method was also developed for rudimentary object avoidance. PA - Pennsylvania conducted 4 replicated trials in peach orchards with the Darwin string thinner. The trials were designed to monitor the effect of low temperatures during bloom following mechanical thinning. Presentations were given for 1025 growers at 1 in-depth workshop, 3 national meetings, and 1 international convention. The string thinner parameters were compared on crop load, leaf area, fruit size, fruit retention, and fruit calcium. A study was conducted to determine the relationship between string number on a mechanical string thinner (Darwin PT-250) and thinning severity on Pink Lady/M.9 apple trees. Trials were conducted on Buckeye Gala/M.9 apple trees that were trained to tall spindle. Different spindle speeds (0 to 300 rpm) were applied to the same trees for two consecutive years. A 1/4 scale thinning robot was built and initial tests performed. A new end effector for removing blossoms was designed and fabricated. This end effector utilizes a spinning brush to gently remove blossoms and a capability of opening and closing as directed by a heuristic control algorithm to remove only selected blossoms. Demonstrations and presentations were held at extension outreach, industry, and professional conferences, including the Washington State Horticultural Association, California Cling Peach Industry, Southeast Professional Fruit Workers, Mid-Atlantic Fruit and Vegetable, International Fruit Tree Association, Cherry Institute, NCW Stone Fruit Day and NE Agricultural and Biological Engineering meetings. Additional outreach efforts included trade journal articles, videos, posters, powerpoints, extension bulletins, posted at the project website (http://abe.psu.edu/scri). PARTICIPANTS: Director: Paul Heinemann, Professor, Agricultural and Biological Engineering, The Pennsylvania State University; Tara Baugher, Tree Fruit Extension Educator, The Pennsylvania State University, Adams County Cooperative Extension; Michael Delwiche, Professor, Biological and Agricultural Engineering, University of California-Davis; Tony Grift, Associate Professor, Agricultural and Biological Engineering, University of Illinois; Karen Lewis, Tree Fruit Regional Specialist, Washington State University Extension; Jude Liu, Assistant Professor, Agricultural and Biological Engineering, The Pennsylvania State University; Gregory Reighard, Professor, Horticulture, Clemson University; James Schupp, Associate Professor, Horticulture, The Pennsylvania State University Fruit Research and Extension Center; David Slaughter, Professor, Biological and Agricultural Engineering, University of California-Davis; Yang Tao, Professor, Biological Engineering, University of Maryland; Christopher Walsh, Professor, Plant Science, University of Maryland; Cooperators: Stephen Miller, USDA-ARS Appalachian Fruit Research Station; Scott Johnson, University of California Kearney Agricultural Center; Roger Duncan, University of California Extension; Janine Hasey, University of California Extension; Greg Henderson, Clemson University, Katie Ellis, Penn State Extension; Penn State Extension; Edwin Winzeler, The Pennsylvania State University Fruit Research and Extension Center. Partner Organizations: USDA; Washington Tree Fruit Research Commission; California Canning Peach Association; State Horticultural Association of Pennsylvania; Pennsylvania Department of Agriculture; South Carolina Peach Council. Training: student participants - Clemson University: Will Henderson Washington State: Meng Wang, Engela Martinson, Nataliya Shcherbatyuk, Dennis Hehnen Penn State: Tom Kon, David Lyons, Celine Kuntz, Ryan Hilton, John Paul Baugher, Amelia Jarvinen. TARGET AUDIENCES: Fruit growers, particularly tree fruit throughout the U.S. and Canada; Potential commercial developers of machinery PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
WA - Hand-held thinning unit trials in both Lapin and Sweetheart cherries reinforced that green fruit thinning results in larger cherries when compared to bloom thinning by mechanical or manual methods and untreated controls. Robada and Goldbar apricot responded favorably to bloom thinning with the hand held device, Darwin string thinner and manual rakes/combs. Blossom thinned fruit was larger than fruit thinned at green fruit stage only (control). Hand held treatments in both varieties yielded the greatest percentage of fruit in first pick. Costs to bloom thin are as follows: manual - $1,200/ acre, handheld - $250.00/acre, Darwin - $62.00. Darwin treatments required the greatest time and costs for follow up green fruit thinning. CA - the best training system is the quad-V and that in vase systems renewal pruning must be conducted. Interest in mechanical string thinning in CA continues to increase, especially among cling peach growers. The manufacturer is designing modifications to the thinner for accommodating the tall tree architectures common in this peach growing area. PA - In peach thinning trials conducted in a season when bloom was 4 weeks early and there were three mornings when temperatures dropped to around 32 deg F, targeted flower removal was 30 to 40%, and crop load, follow-up hand thinning and percent fruit in higher value size categories were reduced in 3 of the 4 trials. Physiological drop in the control plots was significantly more than in the blossom thinned plots. Thinning of apple using the string thinner showed that as the number of strings increased, the level of thinning severity increased. Also, as spindle speed increased, the removal of the number of blossom clusters per limb cross-sectional area increased. The number of blossoms per spur declined as spindle speed increased. While increased spindle speed reduced cropload, injury to spur leaves limited any benefit of increased fruit size. Spindle speed of 300 rpm produced the largest gain in fruit weight of 28 g when compared to the control. However the most severe thinning treatments reduced yield by more than 50%. Fruit quality was generally enhanced with increased spindle speed. There was no relationship between spindle speed and return bloom. The string thinner consistently removed blossoms, but severe thinning treatments (240 - 300 rpm) resulted in high rates of spur removal and reduction in spur leaf area. Spindle speeds of 180 - 210 rpm provided the best overall thinning response and minimized injury to spur leaves. Damage to spur leaves negatively influenced fruit size, fruit retention, and fruit calcium. Growers continued to purchase either Darwin or PT250 string thinners and reported reduced labor requirement and improved fruit size. The manufacturer is automating the string thinner based on 2011 graduate student results with automated positioning and on-going selective thinner work on blossom imaging. Socioeonomic surveys conducted at a Mid-Atlantic producer convention indicated that 41% of participants were very likely to adopt peach thinning technologies; 33% were somewhat likely, 9% were unlikely, and 18% were already making changes.

Publications

• Heinemann, P., J. Schupp, T. Baugher, J. Liu, and W. Messner. 2012. Collaborative efforts with a commercialization partner to develop a vacuum assisted harvest system. International Symposium on Mechanical Harvesting and Handling Systems of Fruits and Nuts. (Abstract). http://www.crec.ifas.ufl.edu/harvest/pdfs/ABSTRACTBOOK2.pdf. page 38.
• Hehnen, D., I. Hanrahan, K. Lewis, J. McFerson, and M. Blanke. 2012. Mechanical flower thinning improves fruit quality of apples and promotes consistent bearing. Scientia Horticulturae 134: 241-244.
• Baugher, T. A., J. R. Schupp, and P. Heinemann. 2012. Innovations in peach thinning - A summary report. PA Fruit News 92(2): 19-22.
• Kon, T., J. Schupp, H. Winzeler, and R. Marini. 2012. Influence of mechanical thinning severity treatments on vegetative and reproductive tissues, fruit set, yield, and fruit quality of 'Buckey Gala.' J. Amer. Soc. Hort. Sci. 2012 Convention. (Abstracts)http://ashs.org/abstracts/m/abstracts12/abstract_id_11688. html.
• Kon, T. M., J. R. Schupp, H. E. Winzeler, and R. P. Marini. 2012. Influence of mechanical string thinning treatments on vegetative and reproductive tissues, fruit set, yield and fruit quality of apple. HortScience 47. (Accepted for Publication).
• Lewis, K. M. and M. Robinson. 2012. Mechanized string thinners, an effective tool for cropload management in organic apricot production. ISHS 2nd International Organic Fruit Research Symposium. Symposium. (Abstract)http://www.tfrec.wsu.edu/pdfs/P2535.pdf. pg. 14.
• Reighard, G. L. and W. G. Henderson. 2012. Mechanical blossom thinning in South Carolina peach orchards. International Symposium on Mechanical Harvesting & Handling Systems of Fruits and Nuts. Lake Alfred, FL. April 1-4, 2012. (Abstract) Book pp. 18-19.
• Baugher, T. A., J. Schupp, P. Heineman, L. Hull, R. Crassweller, G. Krawczyk, R. Marini, C. Lara, S. Prozo, and C. Snyder 2012. Specialty Crop Innovations - Progress and Future Directions. Penn State Cooperative Extension Ag Innovations Pub. 5. http://agsci.psu.edu/frec/resources/online-resources/AgInnovationsDir ections2011.pdf/view.
• Schupp, J., T. A. Baugher, J. L. Frecon, J. Remcheck, and K. Ellis. 2011. Evaluation and Demonstration of New Stone Fruit Varieties and Tree Forms. PA Fruit News 91: 11.
• Schupp, J. and E. Winzeler. 2011. A Precision Electronic Fruit Grading System for the PSU Fruit Research and Extension Center. PA Fruit News 91(1): 38.
• Schupp, J. R. and T. A. Baugher. 2011. Peach Blossom String Thinner Performance Improved with Selective Pruning. HortScience 46(11): 1486-1492.
• Baugher, T., J. Schupp, and P. Heinemann. 2011. Innovations in peach thinning. Proc. New England Vegetable and Fruit Convention, Manchester, New Hampshire, pp. 21-25.

Progress 09/01/10 to 08/31/11

Outputs
OUTPUTS: WA - WSU investigators conducted 1 apricot, 2 apple, and 3 sweet cherry replicated on-farm trials. In addition, they have 3 hand held thinner trials underway in Chile that include the WSU hand held thinner and the commercial "electr-flor" and they provided a WSU hand held device for PA growers to evaluate. In apricot, there were 3 treatments - Darwin string thinner, WSU hand held thinner, and green fruit thinning. Apple trial treatments included Darwin and Bonner mechanical string thinners, WSU hand held thinner, and chemical thinners. Follow up BA treatments were evaluated in one apple trial and a 6 year study was established at WSU to evaluate Bonner string thinner only, chemical thinning only, and mechanical/chemical thinning on alternate years. Field days and demonstrations were attended by 125 growers, and talks at conventions were attended by 200 growers. SC - Clemson collaborators conducted 2 commercial-scale (25+ acres) replicated trials and 1 non-replicated trial in peach. String thinning treatments included top, underneath, and/or side spindle orientations, and control treatments included hand blossom and green fruit hand thinning. A mechanical thinning demonstration was held in March, and 3 presentations were given at SC peach meetings and 2 at meetings in other states (UT, TN) for a total of 450 growers. CA - California extension educators reported that growers from their three major peach growing regions conducted commercial-scale trials on mechanical blossom thinning, with support from UC Extension and the CA Canning Peach Association. PA - Pennsylvania had 3 replicated trials with the Darwin string thinner. String thinner trials were with automated positioning systems to improve uniformity of thinning and were conducted on peach. Graduate students from PSU and Carnegie Mellon designed and tested sensor positioning systems. 440 growers representing 20,000 acres attended field day demonstrations and Mid-Atlantic fruit conventions. Selective thinner development included further machine vision testing, laser range finding, and image analysis of peach trees both in the lab and in the orchard. Two end effector blossom removal mechanisms were designed and one was fabricated and tested by hand. A prototype 1/4-scale unit was fabricated by Penn State and U. of Illinois personnel, with an identical copy made and sent to Illinois for further testing. PA and WA producers participated in a socioeconomic survey designed to determine the needs and potentials for automation and sensor technologies in specialty crops. To improve precision and efficiency in orchard enterprises, the participants rated fruit thinning, and harvesting as the areas of greatest need. Demonstrations and presentations were held at extension outreach, industry conventions, and professional conferences, including the Washington State Horticultural, California Cling Peach Industry, Southeast Professional Fruit Workers, Mid-Atlantic Fruit and Vegetable, and NE Agricultural and Biological Engineering meetings. Additional outreach efforts included trade journal articles, videos, powerpoints, extension bulletins, and posters. PARTICIPANTS: Project Members - Director: Paul Heinemann, Professor, Agricultural and Biological Engineering, The Pennsylvania State University; Tara Baugher, Tree Fruit Extension Educator, The Pennsylvania State University, Adams County Cooperative Extension; Michael Delwiche, Professor, Biological and Agricultural Engineering, University of California-Davis; Tony Grift, Associate Professor, Agricultural and Biological Engineering, University of Illinois; Jayson Harper, Professor, Agricultural Economics and Rural Sociology, The Pennsylvania State University; Karen Lewis, Tree Fruit Area Extension Educator, Washington State University Extension; Jude Liu, Assistant Professor, Agricultural and Biological Engineering, The Pennsylvania State University; Marvin Pitts, Associate Professor, Biological Systems Engineering, Washington State University; Gregory Reighard, Professor, Horticulture, Clemson University; James Schupp, Associate Professor, Horticulture, The Pennsylvania State University Fruit Research and Extension Center; David Slaughter, Professor, Biological and Agricultural Engineering, University of California-Davis; Yang Tao, Professor, Biological Engineering, University of Maryland; Christopher Walsh, Professor, Plant Science, University of Maryland; Cooperators - Stephen Miller, USDA-ARS Appalachian Fruit Research Station; Scott Johnson, University of California Kearney Agricultural Center; Roger Duncan, University of California Extension; Janine Hasey, University of California Extension; Greg Henderson, Clemson University, Katie Ellis, Penn State Extension; Penn State Extension; Edwin Winzeler, The Pennsylvania State University Fruit Research and Extension Center. Partner Organizations: USDA; Washington Tree Fruit Research Commission; California Canning Peach Association; State Horticultural Association of Pennsylvania; Pennsylvania Department of Agriculture; South Carolina Peach Council. Training: student participants Clemson University: Will Henderson Penn State: Tom Kon, David Lyons, Robin Pritz, Reuben Dise, Celine Kuntz, Ryan Hilton, John Paul Baugher, Amelia Jarvinen Carnegie Mellon: Matt Aastad TARGET AUDIENCES: Fruit growers, particularly tree fruit throughout the U.S. and Canada; Potential commercial developers of machinery PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
WA - Hand-held /'Lapin' cherry - A clipped green fruit treatment resulted in a greater percentage of fruit in size 10 and larger when compared to the hand held blossom thinned treatment. Time to apply the hand held treatment was several seconds compared to a minute or longer for green fruit clipping. Hand held/'Sweetheart' cherry - There was no significant difference in surviving flower numbers across bloom stage and head / spine treatments. Fruit size row 10 and larger was best achieved by hand fruitlet thinning (100%) and hand flower thinning at 20-40% full bloom (92%). In a PA trial on this variety, the percentage of 10 row and larger was highest in a heavy thinning treatment, followed by fast thinning treatment. There was no significant difference between light thinning and control treatments. 'Robada' apricot responded favorably to the hand held device. Hand held treated fruit peaked on sizes 64 and 72. Darwin thinned fruit peaked on sizes 72 and 96. Green fruit thinned only fruit peaked on sizes 80 and 96. First pick volume was largest on Darwin thinned rows, followed by hand held thinned rows. CA - Interest in mechanical string thinning in CA continues to increase, especially among cling peach growers. The manufacturer is designing modifications to the thinner for accommodating the tall tree architectures common in this peach growing area. SC - In a replicated trial on 'Coronet' peach (25 acres) grown in traditional open center culture, labor cost savings with the string thinner (used over the tops of the trees; 61% blossom removal) followed by green fruit thinning, compared to hand bloom thinning or green fruit hand thinning was $491 per acre. The labor cost savings along with a modest increase in size distribution increased gross revenue by 7.6%, or $1041 per acre. In a replicated trial with open center-trained 'Clemson Lady' (26 acres), cost savings with the string thinner (operated underneath or on the sides of trees; 30% removal) was only $58 per acre. In a high density non-replicated 'Fire Prince' trial (non-replicated), mechanical thinning (underneath or side treatment; 39% removal) vs a hand bloom thinned control treatment (60% reduction) reduced total thinning costs from $1188 to $560 per acre. PA -PSU and CMU graduate students tested ultrasonic and laser sensors to detect canopy shape and distance and automatically control the position of the string thinner. Based on blossom removal comparisons between automated and operator controlled string thinning, the automated systems were generally as good as a human at maintaining canopy engagement and may be economically viable methods of augmenting mechanical thinning. A video on this new technology is on-line at www.abe.psu.edu/scri. NE growers continued to purchase either Darwin (for planar tree canopies) or PT250 (for open vase-shaped canopies) string thinners and reported reduced labor requirement and improved fruit size. Socioeonomic survey results indicated that field trials to present evidence of increased management efficiency, improved fruit quality, and increased net income would result in a faster rate of adoption of new technologies.

Publications

• Baugher, T. A., J. Schupp, K. Ellis, E. Winzeler, J. Remcheck, K. Lesser, and K. Reichard. 2010. Mechanical string thinner reduces crop load at variable stages of bloom development of peach and nectarine trees. HortScience 45(9):1327-1331.
• Baugher, T. A. and J. Schupp. 2010. Relationship between 'Honeycrisp' crop load and sensory panel evaluations of the fruit. J. Amer. Pomological Soc. 64:226-233.
• Ellis, K., T. A. Baugher, and K. Lewis. 2010. Use of survey instruments to assess technology adoption for tree fruit production. HortTechnology 20:1043-1048.
• Miller, S., J. Schupp, T. Baugher, and S. Wolford. 2011. Performance of mechanical thinners for bloom or green fruit thinning in peaches. HortScience 46:43-51.
• Aasted, M., R. Dise, T. A. Baugher, P. H. Heinemann, and S. Singh. 2011. Autonomous mechanical thinning using scanning LIDAR. ASABE Paper No 11011. American Society of Agricultural and Biological Engineers. 11 pp.

Progress 09/01/09 to 08/31/10

Outputs
OUTPUTS: "Innovative Thinning" project activities focused on further testing and modification of non-selective mechanical thinner technologies, field trials to assess horticultural and economic benefits of non-selective thinning, further development of selective thinning components, outreach demonstrations and publications to promote technology transfer and commercialization, and reports for advisory panels and other stakeholder groups. Washington State thinning trials with two string thinners were featured in 9 outreach events. Replicated on-farm trials included 3 sweet cherry, 3 apple, 1 apricot and 1 nectarine. On-farm demonstrations included 1 pear and 1 apricot. A new hand held string thinner was tested in 7 sweet cherry trials. 725 people attended the outreach events. California had 10 replicated trials in cling peach and 20 demonstrations or grower run trials. One of the grower trials was on pears; the others were in cling or fresh market peach. Three string thinner units were used in these trials. 80 people attended the various demonstrations. South Carolina trials were conducted on 3 grower farms (2 with traditional open center trained trees and the other with a high-density quad-V system). Alternative orientations of the string thinner, e.g., over the top and side/vertical, were tested in the open center systems. Outreach events reached an estimated 85 participants representing 18,000 acres. Pennsylvania had 6 replicated trials with the string thinner and 2 with a USDA drum shaker with a new rod displacement system to improve thinning efficiency and reduce trunk damage. String thinner trials focused on string pattern arrangements and an automated positioning system to improve uniformity of thinning. 300 growers representing 20,000 acres attended presentations. Selective thinner development included further machine vision testing, laser range finding, and image analysis of peach trees both in the lab and in the orchard. Two end effector blossom removal mechanisms were designed and one was fabricated and tested by hand. Further design details on the second mechanism have been developed. Two used FANUC M-16 industrial robots were purchased and delivered to the University of Illinois and Penn State. These will provide the positioning of the blossom removal mechanisms guided by the vision system. Demonstrations and presentations were held at 42 extension outreach, industry conventions, and professional conferences, including the Cumberland-Shenandoah, Washington State Horticultural, Sacramento Valley Cling Peach, California Cling Peach Industry, Illinois Specialty Crops, Ohio Produce Growers and Marketers, USDA Systems, SE Fruit and Vegetable, South Georgia/North Florida and South Carolina Peach, National Peach, Mid-Atlantic Fruit and Vegetable, International Fruit Tree Association, Nuffield International Farming Scholars, New Jersey Tree Fruit IPM, American Society for Horticultural Science, and NE Agricultural and Biological Engineering meetings. Additional outreach efforts included trade journal articles, videos, powerpoints, extension bulletins, and posters that are available at the project web site (http://www.abe.psu.edu/scri/). PARTICIPANTS: Project Members: Director: Paul Heinemann, Professor, Agricultural and Biological Engineering, The Pennsylvania State University; Tara Baugher, Tree Fruit Extension Educator, The Pennsylvania State University, Adams County Cooperative Extension; Michael Delwiche, Professor, Biological and Agricultural Engineering, University of California-Davis; Tony Grift, Associate Professor, Agricultural and Biological Engineering, University of Illinois; Jayson Harper, Professor, Agricultural Economics and Rural Sociology, The Pennsylvania State University; Karen Lewis, Tree Fruit Area Extension Educator, Washington State University Extension; Jude Liu, Assistant Professor, Agricultural and Biological Engineering, The Pennsylvania State University; Marvin Pitts, Associate Professor, Biological Systems Engineering, Washington State University; Gregory Reighard, Professor, Horticulture, Clemson University; James Schupp, Associate Professor, Horticulture, The Pennsylvania State University Fruit Research and Extension Center; David Slaughter, Professor, Biological and Agricultural Engineering, University of California-Davis; Yang Tao, Professor, Biological Engineering, University of Maryland; Christopher Walsh, Professor, Plant Science, University of Maryland; Cooperators: Stephen Miller, USDA-ARS Appalachian Fruit Research Station; Scott Johnson, University of California Kearney Agricultural Center; Roger Duncan, University of California Extension; Janine Hasey, University of California Extension; Greg Henderson, Clemson University, Katie Ellis, Penn State Extension; Jim Remcheck, Penn State Extension; Edwin Winzeler, The Pennsylvania State University Fruit Research and Extension Center. Partner Organizations: USDA; Washington Tree Fruit Research Commission; California Canning Peach Association; State Horticultural Association of Pennsylvania; Pennsylvania Department of Agriculture; South Carolina Peach Council. Training: student participants Clemson University: Will Henderson Penn State: Russell Rohrbaugh, Tom Kon, Robin Pritz, David Lyons; Carnegie Mellon: Matt Aastad; Millersville: Celine Kuntz; Grove City College: Evan Moore; McDaniel College: Jennifer Rouzer; Madison University: Ryan Hilton; Oberlin College: Amelia Jarvinen; Modesto Jr College: Rose Lorenzo TARGET AUDIENCES: Fruit growers, particularly tree fruit throughout the U.S. and Canada; Potential commercial developers of machinery PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
WA - Repeated field trial results in both apricot and nectarine have shown that with correct timing and application, string thinner that reduces bloom and subsequent fruit set and increases final fruit size. Increase in final fruit size in mechanically thinned blocks is equal to that measured in hand bloom thinned trees. The 2010 cost for hand bloom thinning ranged from $540 to 750 per acre. Mechanical thinning was estimated at $40 to 60 per acre. Green fruit thinning in string thinned nectarine and apricot blocks was reduced by 40 to 50% when compared to green fruit thinning alone. There was no initial significance in green fruit thinning time or corresponding costs between mechanically thinned and hand blossom thinned trees. With positive results in stone fruit trials for 3 years, Blueline Manufacturing in Moxee, Washington became a Darwin string thinner distributor in the summer of 2010 and 2 machines were ordered. Interest in mechanical thinning in apple, pear and cherry is increasing. Mixed results in cherry led to securing $100,000 in industry funds to develop a hand held string thinning device. This is an example of leveraging SCRI funding and the development of a new collaboration with WSU CPAAS and the University of Chile. CA - In the 10 replicated trials on cling peach, generally positive results were found with the string thinner. All 10 experiments showed an increase in fruit size at the time of hand thinning and/or harvest. Seven of the 10 required less hand thinning which saved the grower anywhere from $200 to $500 per acre. About half of the trials had increased yields of 0.5 to 3.1 tons/acre. However, several lost 2 to 4 tons. Overall, most of the trials showed increased profitability of anywhere from about $200 up to nearly $1000 per acre. The few that lost money were generally due to varieties that set poorly in 2010. Interest in California is increasing, especially among cling peach growers. One grower purchased a unit and another made his own. One fresh market peach grower also purchased a unit. SC - Data from 2010 peach trials on the open center system suggested an overall cost reduction in green fruit thinning of $85 to 93 per acre compared to the grower standard hand bloom thinning, with a corresponding increase in gross revenues based on size distribution of $236 to 479 per acre. Relocation of the flow valve permitted improved tree canopy access. PA - A 6 column helix string arrangement compared to a 2 column 9 string arrangement increased thinning uniformity in 1 out of 3 trials. A string thinner modified to automatically adjust to canopy width and angle increased thinning efficacy and uniformity, and the thinner manufacturer plans to model a new thinner based on the Penn State prototype. Eight string thinners were purchased in 2010 by NE growers, and all reported reduced labor requirement. The drum shaker reduced crop load and follow-up hand thinning time significantly over a conventional hand thinning technique only when operating at 300 to 400 cycles per minute. Preliminary data suggest bark damage was less than obtained with previous prototypes, but damage was not eliminated, which is one of the ultimate goals.

Publications

• Ellis, K. 2009. Developments in Technology and Automation for Tree Fruit. Proc. Great Lakes Fruit, Vegetable, and Farm Market Expo, Grand Rapids, MI. Tree Fruit Session. pp. 4-7.
• Kon, T. M., W. E. Winzeler, and J. R. Schupp. 2010. Golden Delicious cropload adjustment with the Equilifruit disk. HortScience 45(8):S256 (Abstract).
• Baugher, T. A., J. Schupp, K. Ellis, E. Winzeler, J. Remcheck, K. Lesser, and K. Reichard. 2010. Mechanical string thinner reduces crop load at variable stages of bloom development of peach and nectarine trees. HortScience 45(9):1327-1331.
• Baugher, T. A., J. Schupp, K. Ellis, J. Remcheck, E. Winzeler, R. Duncan, S. Johnson, K. Lewis, G. Reighard, G. Henderson, M. Norton, A. Dhaddey, and P. Heinemann. 2010. String blossom thinner designed for variable tree forms increases crop load management efficiency in trials in four U.S. peach growing regions. HortTechnology 20:409-414.
• Schupp, J., P. Heinemann, T. Baugher, S. Miller, J. Liu, R. Dise, and A. Leslie. 2010. Innovative technologies for thinning of fruit. 2010. Ohio Produce Growers and Marketers Association Today. Pataskala, OH. pp. 6-9.
• Schupp, J., T. A. Baugher, R. Crassweller, K. Ellis, E. Winzeler, J. Remcheck, and T. Kon. 2010. Labor efficient production systems. PA Fruit News 90(2).
• Baugher, T. A., J. Schupp, P. Heinemann, S. Miller, K. Ellis, E. Winzeler, K. Reichard, J. Remcheck, C. Musselman, A. Leslie, R. Rohrbaugh, S. Wolford, M. Schupp, C. Kuntz, E. Moore, J. Koan, C. Anders, and T. Kon. 2010. Innovative technologies for thinning fruit. PA Fruit News 90(3):20.
• Emery, K. G., D. M. Faubion, C. S. Walsh, and Y. Tao. 2010. Development of 3-D range imaging system to scan peach branches for selective robotic blossom thinning. ASABE Paper number 10-09202. The American Society of Agricultural and Biological Engineers. St. Joseph, MI. 10 pp.
• Heinemann, P., J. Schupp, and T. A. Baugher. 2010. Innovative technologies for thinning of fruit. HortScience 45(8):S199 (Abstract).
• Schupp, J., T. A. Baugher, K. Ellis, J. Remcheck, E. Winzeler, R. Duncan, S. Johnson, K. Lewis, G. Reighard, G. Henderson, M. Norton, A. Dhaddey, and P. Heinemann. 2010. String blossom thinner designed for variable tree forms increases crop load management efficiency in trials in four peach growing regions. HortScience 45(8):S199 (Abstract).

Progress 09/01/08 to 08/31/09

Outputs
OUTPUTS: Innovative Thinning project activities focused on non-selective mechanical thinner modifications to increase adaptation to variable tree architectures, developing and integrating electronic and mechanical technologies for selective thinning, field trials to assess horticultural and economic benefits of non-selective thinning, outreach demonstrations and publications to increase technology transfer and commercialization, and reports for advisory panels and other stakeholder groups. Trials with the mechanical blossom string thinner were performed Spring 2009 in 13 PA, 3 SC, 8 WA, and 4 CA commercial and research orchards. The USDA drum shaker was tested in 3 PA orchards during the bloom and green fruit stages. Conventional hand thinning at the green fruit stage was the control treatment. Varying operational speeds, blossom stages, and pruning modifications to improve access by the thinner were assessed. Data were uniformly collected across all regions to determine blossom removal rates, fruit set, labor required for follow-up hand thinning, fruit size distribution at harvest, yield, and economic impact. Case study interviews of 11 growers and orchard managers were conducted to assess sociological implications relative to stakeholder adoption. These growers had cooperated in trials on a total of 154 acres. Selective thinner development included machine vision testing, laser range finding, and image analysis of peach trees both in the lab and in the orchard. Design criteria for selective thinning were developed based on blossom identification and removal force assessments. Demonstrations and presentations were held at 21 extension outreach and industry conventions, including the SE Peach Convention, CA Peach Canning Conference, WA Horticultural Convention, Mid-Atlantic Fruit & Vegetable Convention, Ontario Fruit & Vegetable Convention, NY Fruit & Vegetable Expo, Cornell Extension Fruit School, Clemson Fruit Producer Meeting, New Zealand Summerfruit Meeting, Penn State Engineering Solutions Workshop, Penn State Fruit Research & Extension Center Field Day, Clemson Research Center Peach Field Day, WA Fruit Research Field Day, UC Davis Thinning Field Days, UC Kearney Research Center Thinning Demonstration, Penn State Workshop on Tree Architecture for Mechanization, Penn State Spotlight on Peach Thinning, and Pacific NW Engineering Solutions Workshop. Additional outreach efforts included the production of videos, powerpoints, extension bulletins, and posters that are available at the project web site (http://www.abe.psu.edu/scri/). Twenty-five outreach stories were circulated through trade magazines and newspapers, including the Good Fruit Grower, Cling Peach Review, Ag Alert, Fruit Grower News, American Fruit Grower, and Peach Times. The project advisory panel met during the Mid-Atlantic Fruit & Vegetable Convention and is regularly updated by list-serve reports and timely updates at the web site. Team members also were invited to give special presentations to 8 stakeholder organizations, including PA legislators, the PA Fruit Industry Task Force, CA Peach Canning Association, WA Tree Fruit Research Commission, and Horticultural Association of PA. PARTICIPANTS: Individuals: Project Director: Paul Heinemann, Professor, Agricultural and Biological Engineering, The Pennsylvania State University; Tara Baugher, Tree Fruit Extension Educator, The Pennsylvania State University, Adams County Cooperative Extension; Michael Delwiche, Professor, Biological and Agricultural Engineering, University of California-Davis; Tony Grift, Associate Professor, Agricultural and Biological Engineering, University of Illinois; Jayson Harper, Professor, Agricultural Economics and Rural Sociology, The Pennsylvania State University; Karen Lewis, Tree Fruit Area Extension Educator, Washington State University Extension; Jude Liu, Assistant Professor, Agricultural and Biological Engineering, The Pennsylvania State University; Marvin Pitts, Associate Professor, Biological Systems Engineering, Washington State University; Gregory Reighard, Professor, Horticulture, Clemson University; James Schupp, Associate Professor, Horticulture, The Pennsylvania State University, Fruit Research and Extension Center; David Slaughter, Professor, Biological and Agricultural Engineering, University of California-Davis; Yang Tao, Professor, Biological Engineering, University of Maryland; Christopher Walsh, Professor, Plant Science, University of Maryland; Stephen Miller, Research Horticulturist, USDA-ARS Appalachian Fruit Research Station, Kearneysville, WV; Scott Johnson, Kearney Agricultural Center, CA; Roger Duncan, UC-Davis; Katie Ellis, Penn State Extension, Jim Remcheck, Penn State Extension. Partner Organizations: USDA Washington Tree Fruit Research Commission; California Canning Peach Association; State Horticultural Association of Pennsylvania; Pennsylvania Department of Agriculture; South Carolina Peach Council. Training: student interns: Penn State: Alex Leslie, Russell Rohrbaugh; Michigan State: Jacob Koan; Kalamazoo College: Cody Musselman; Graduate student: Reuben Dise. TARGET AUDIENCES: Fruit growers, particularly tree fruit throughout the US and Canada; Potential commercial developers of machinery PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
String thinner trials to assess optimum operational parameters for varying growing regions and tree forms showed reduced labor costs compared to hand thinned controls and increased crop value due to a larger distribution of fruit in higher market value sizes. Blossom removal ranged from 20-55%, hand thinning requirement was reduced by 25-65%, and fruit size distribution improved in all but one trial. Net economic impact at optimum tractor and spindle speeds was $462-$1490 and $230-$847 per acre for processing and fresh market peaches, respectively. Trials with the string thinner at varying bloom stages showed the thinning window is from pink to petal fall. Trials on modifications in tree training to improve access by the string thinner indicated detailed pruning for targeted crop loads was superior to standard pruning. Studies with a new drum shaker prototype adapted from a blackberry harvester demonstrated increased thinning consistency compared to previous research with a citrus drum shaker. Yield was reduced in some fresh fruit trials, and future trials will address this concern. Several combination treatments, including the string thinner + hand blossom thinning, the string thinner + the drum shaker, and string thinner treatments on both the sides and tops of tree suggested additional strategies for achieving the most desirable thinning results. Experiments for selective thinning validated 3-D and UV imaging precision and established force required to remove blossoms (avg. 0.10 lb). All the growers who agreed to participate in case study interviews indicated the string thinner impacted orchard management by making crop load management more efficient and by reducing follow-up hand thinning time. Eighty percent of the growers noted fruit from trees that had been thinned were larger. Observations included the following: hand thinning of peaches completed earlier allowing more timely work in other crops, employee satisfaction with thinners as they saved them time and minimized ladder use, improved work load distribution. Of the stakeholders who were surveyed following the workshop on tree architecture for mechanization, 78% indicated workshop outcomes included planting new competitive orchard systems at higher tree densities and adopting peach pruning and training strategies for better targeting crop load. Horticulture conference participants surveyed following a technology session rated thinning and harvesting as the areas of greatest need to improve precision and efficiency in orchard enterprises. On-farm trials demonstrating management benefits were noted to be effective tools for encouraging technology adoption. Five refereed papers have been published in journals such as HortTechnology and HortScience. Professional papers were presented at the NE Agricultural and Biological Engineering Conference and the ISHS Precision Agriculture Conference. The new peach tree thinner version of the string thinner (PT250) developed specifically for this project has been commercialized and will now be manufactured in North America. Distributors have been identified in CA and PA.

Publications

• Lesser, K., T. Auxt Baugher, J. Schupp, S. Miller, M. Harsh, K. Reichard. 2008. Mechanical peach thinners reduce labor inputs and increase fruit size. ACTA Horticulturae. Proc. International Society for Horticultural Science. Application of Precision Agriculture for Fruits and Vegetables. Abstract, p. 58.
• Baugher, T. Auxt, J. Schupp, S. Miller, M. Harsh, K. Lesser, K. Reichard, E. Sollenberger, M. Armand, L. Kammerer, M. Reid, L. Rice, S. Waybright, B. Wenk, M. Tindall, E. Moore. 2008. Chemical and mechanical thinning of peaches. PA Fruit News 88(3).
• Ngugi, H. and J. Schupp. 2009. Evaluation of the risk of spreading fire blight in apple orchards with a mechanical string blossom thinner. HortScience 44(3):1-4.
• Heinemann, P., J. Liu, T. Baugher, J. Schupp. 2009. Mechanized fruit thinning. Proc. Northeast Agricultural & Biological Engineering Conference. Halifax, NS. 6 pp.
• Baugher, T. Auxt, J. Schupp, K. Lesser, and K. Reichard. 2009. Horizontal string blossom thinner reduces labor input and increases fruit size in peach trees trained to open-center systems. HortTechnology 19(4):755-761.
• Lesser, K., T. Auxt Baugher, J. Schupp, S. Miller, M. Harsh, K. Reichard. 2008. Mechanical peach thinners reduce labor inputs and increase fruit size. Proc. Empire State Fruit and Vegetable Expo, pp. 7-9.
• Baugher, T. Auxt, J. Schupp, S. Miller, M. Harsh, K. Lesser, K. Reichard. 2008. Thinning Peach Trees: Tools to Meet your New Years Resolutions. Proc. International Fruit Tree Association Annual Conference. (February). Abstract, p. 11.
• Schupp, J., T. Auxt Baugher, S. Miller, R.M. Harsh, K. Lesser, K. Reichard. 2008. Mechanical thinning of peach trees reduces labor inputs and increases fruit size. HortTechnology 18:660-670.
• Baugher, T. Auxt, J. Schupp, S. Miller, M. Harsh, K. Lesser, K. Reichard. 2008. Thinning peach trees: Tools to meet your New Years resolutions. Compact Fruit 41:8-9.
• Baugher, T. Auxt, J. Schupp, M. Harsh, L. Hull, J. Travis, and K. Lesser. 2008. Ag Innovations - Progress and Future Directions. Penn State Cooperative Extension Pub., 16 pp.
• Baugher, T. Auxt, J. Schupp, L. Hull, H. Ngugi, J. Travis, and K. Ellis. 2009. Specialty Crop Innovations - Progress and Future Directions. Penn State Cooperative Extension Pub., 16 pp.