Autio, Wesley (autio@umass.edu) – University of Massachusetts; Black, Brent (brent.black@usu.edu) – Utah State University; Bradshaw, Terence (tbradsha@uvm.edu) – University of Vermont; Casamali, Bruno (bcasamali@gmail.com) - University of Georgia; Jon (jon.clements@umass.edu) – University of Massachusetts; Cline, John (jcline@uoguelph.ca) - University of Guelph, Ontario; Cochran, Diana (dianac@iastate.edu) – Iowa State University; Cowgill, Win (wincowgill@mac.com) - Rutgers University, retired; Crassweller, Rob (rmc7@psu.edu) – Pennsylvania State University; Fallahi, Esmaeil (efallahi@uidaho.edu) – University of Idaho; Fazio, Gennaro (gf35@cornell.edu) – Cornell University; Heyduck, Robert (rheyduck@nmsu.edu) - New Mexico State University; Hoover, Emily (hoover@umn.edu) – University of Minnesota; Kalcsits, Lee (lee.kalcsits@wsu.edu) – Washington State University; Kon, Tom ( tom_kon@ncsu.edu - North Carolina State University; Kushad, Mosbah (kushad@illinois.edu) – University of Illinois; Lang, Gregory (langg@msu.edu) – Michigan State University; Marini, Richard (rpm12@psu.edu) – Pennsylvania State University; Minas, Ioannis (ioannis.mias@colostate.edu) – Colorado State University; Moran, Renae (rmoran@maine.edu) – University of Maine; Muehlbauer, Megan (muehlbauer@njaes.rutgers) - Rutgers University; Musacchi, Stefano, (stefano.musacchi@wsu.edu) –Washington State University; Pieper, Jeff (jeff.pieper@colostate.edu - Colorado State University; Reighard, Gregory (grghrd@clemson.edu) – Clemson University; Robinson, Terence (tlr1@cornell.edu) - Cornell University; Sherif, Sherif (ssherif@vt.edu) – Virginia Tech; Stasiak, Matt (mstasiak@wisc.edu) – University of Wisconsin; Warmund, Michele (warmundm@missouri.edu) - University of Missouri; Wolfe, Dwight (dwolfe@uky.edu) – University of Kentucky; Xu, Hao (hao.xu@uky.edu) – Agriculture and Agri-Food Canada; Yoder, Keith (ksyoder@vt.edu) Virginia Tech;
Eight multi-location trials are in progress to evaluate new rootstocks of apple, peach, cherry and pear and to evaluate new orchard systems for pear and sweet cherry. Two peach and one tart cherry trials were competed during 2018 and in 2019 data will summarized and manuscripts will be submitted to peer-reviewed journals. Trees have been propagated for an apple rootstock trial to be planted in 2019. Rootstock trials are being planned and nurseries are propagating trees for 3 future multi-state trials for sweet cherry (2021), pear (2021) and apricot (2020 or 2021).
Short-term Outcomes:
• Results from NC140 trials in Wisconsin have demonstrated the high productivity of dwarfing rootstocks and their applicability in high density systems (WI). Progressive Wisconsin apple growers continue to plant tall spindle systems.
• Based on research results, irrigation recommendations for peach have been modified for Georgia to include irrigation during and after planting.
• B.9, a commonly planted dwarfing rootstock in many states, has inadequate vigor for Honeycrisp to fill the space in a tall spindle production system. A larger dwarf rootstock such as G.935 is now recommended in several states for Honeycrisp in tall spindle system.
Output:
• In B.C., highest yields for Honeycrisp apple were on the rootstocks CG.3001, CG.4004 and G.202N, and for sweet cherry the combination of Gisela 6 x Tall Spindle Axe was superior.
• Prunus hybrid rootstocks were most productive on high pH soils in CO and could have a significant impact on Colorado orchard profitability as well as other western states.
• Several Geneva apple rootstocks, including Geneva 935, Geneva 4004, and Geneva 41 seem to be suitable for climate and soil conditions of southwest Idaho.
• The Modi apple cultivar represents an opportunity for organic and commercial growers to reduce the number of fungicide applications while maintaining taste.
• Typical very warm (20 C) night temperatures in September again prevented Aztec Fuji from coloring (<25% red blush) and thus it is not recommended for elevations below 300 m in the South Carolina Piedmont. These results can be extended throughout the south.
Activities:
• Trials on grower’s farms yielded information on rootstock adaptability that was not known from experiment station trials, such as cold hardiness evaluation. Performance of high density sweet cherry orchards using several dwarfing rootstocks has stimulated growers to expand sweet cherry acreage in NY State.
• The NC-140 Cooperative Rootstock Trials provide Midwestern fruit producers with relevant information regarding the performance of rootstocks under erratic environmental conditions and the opportunity to observe growth and fruiting of apple and peach trees grown on multiple rootstocks (MO).
Milestones:
• The NC-140 comparative plantings have hastened the testing and commercialization of the disease resistant Geneva apple rootstocks.
• The 2010 apple rootstock trial demonstrated that several Geneva rootstocks were less susceptible to fire blight than M.9 clones currently used by Kentucky growers for high-density orchards. The most productive rootstocks included CG.4004, G.222, G.935N, and G.814. using this information several Kentucky growers decided to adopt high density systems using Geneva rootstocks.
• High-density pear training systems coupled with improved rootstocks is generating new interest among NY growers to plant pears.
• Sweet cherry is being considered by growers with U-Picks as part of their farm with the whole-tree-renewal treatment showing promise (Nova Scotia, CA).