James Schupp, Ph.D.

James Schupp, Ph.D.

  • Professor of Pomology
Fruit Research and Extension Center
PO Box 330,
290 University Drive

Biglerville, PA 17307

Areas of Expertise

  • Tree fruit production
  • Orchard management systems
  • Crop load management of tree fruit
  • Fruit tree pruning and training


  • PhD., Ohio State University, 1988
  • M.S., Ohio State University, 1985
  • B.S., Bowling Green State University, 1978


Sampling apple trees to accurately estimate mean fruit weight and fruit size distribution
HortScience, Marini, Richard P., Schupp, James R., Baugher, Tara Auxt, Crassweller, Robert, 2019

Relationships between fruit weight and diameter at 60 days after bloom and at harvest for three apple cultivars
HortScience, Marini, Richard P., Schupp, James Rawlinson, Baugher, Tara Auxt, Crassweller, Robert Michael, 2019

Comparison of chemical blossom thinners using ‘golden delicious’ and ‘gala’ pollen tube growth models as timing aids
HortScience, Kon, Thomas M., Schupp, James Rawlinson, Yoder, Keith S., Combs, Leon D., Schupp, Melanie A., 2018

Rootstock performance in the 2009 NC-140 peach trial across 11 states
Acta Horticulturae, Reighard, G. L., Bridges, W., Archbold, D., Atucha, A., Autio, W., Beckman, T., Black, B., Chavez, D., Coneva, E., Day, K., Kushad, M., Johnson, R. S., Lindstrom, T., Lordan, J., Minas, I., Ouellette, D., Parker, M. L., Pokharel, R., Robinson, T. L., Schupp, J., Warmund, M., Wolfe, D., 2018

Prediction of bitter pit in ‘Honeycrisp’ apples and best management implications
HortScience, Baugher, Tara Auxt, Marini, Richard, Schupp, James R., Watkins, Christopher B., 2017

A method for quantifying whole-tree pruning severity in mature tall spindle apple plantings
HortScience, Schupp, James R., Winzeler, H. Edwin, Kon, Thomas M., Marini, Richard P., Baugher, Tara A., Kime, Lynn F., Schupp, Melanie A., 2017

Design and field test of a low-cost apple harvest-assist unit
Transactions of the ASABE, Zhang, Z., Heinemann, P. H., Liu, J., Schupp, J. R., Baugher, T. A., 2016

Development of a selective automated blossom thinning system for peaches
Transactions of the ASABE, Lyons, David, Heinemann, Paul Heinz, Schupp, James Rawlinson, Baugher, T. A., Liu, Jude, 2015

Thinning tall spindle apple based on estimations made with a hand-thinning gauge
HortTechnology, Kon, Thomas M., Schupp, James Rawlinson, 2013

Influence of mechanical string thinning treatments on vegetative and reproductive tissues, fruit set, yield, and fruit quality of 'Gala' apple
HortScience, Kon, Thomas M., Schupp, James R., Edwin Winzeler, H., Marini, Richard P., 2013

1-aminocyclopropane carboxylic acid shows promise as a chemical thinner for apple
HortScience, Schupp, James R., Kon, Thomas M., Edwin Winzeler, H., 2012

Peach blossom string thinner performance improved with selective pruning
HortScience, Schupp, James Rawlinson, Baugher, T. Auxt, 2011

Image analysis of blush coverage extent and measures of categorical blush intensity in 'honeycrisp' apples
HortScience, Winzeler, H. E., Schupp, James Rawlinson, 2011

Effect of abscisic acid and benzyladenine on fruit set and fruit quality of apples
HortScience, Greene, Duane W., Schupp, James R., Edwin Winzeler, H., 2011

Performance of mechanical thinners for bloom or green fruit thinning in peaches
HortScience, Miller, Stephen S., Schupp, James R., Baugher, Tara A., Wolford, Scott D., 2011

Mechanical string thinner reduces crop load at variable stages of bloom development of peach and nectarine trees
HortScience, Auxt Baugher, T., Ellis, K., Remcheck, J., Lesser, K., Schupp, J., Winzeler, E., Reichard, K., 2010

Late-life decline in well-being across adulthood in germany, the united kingdom, and the united states
Psychology and aging, Gerstorf, Denis, Ram, Nilam, Mayraz, Guy, Hidajat, Mira, Lindenberger, Ulman, Wagner, Gert G., Schupp, Jürgen, 2010

String blossom thinner designed for variable tree forms increases crop load management efficiency in trials in four united states peach-growing regions
HortTechnology, Auxt Baugher, T., Schupp, J., Ellis, K., Remcheck, J., Winzeler, E., Duncan, R., Johnson, S., Lewis, K., Reighard, G., Henderson, G., Norton, M., Dhaddey, A., Heinemann, P., 2010