SAES-422 Multistate Research Activity Accomplishments Report

Status: Approved

Basic Information


Autio, Wesley ( – University of Massachusetts; Atucha, Amaya ( – University of Wisconsin-Madison; Black, Brent ( – Utah State University; Blanco, Victor ( – Washington State University; Blatt, Suzanne - Agriculture and Agri-Food Canada; Bolivar-Medina, Jenny ( - Washington State University; Bradshaw, Terence ( – University of Vermont; Cameron, Todd ( – Cameron Nursery, LLC; Carter, Kathryn ( - Ontario Ministry of Food, and Agriculture; Casagrande Biasuz, Erica ( - Washington State University; Chang, Yongjian ( - North American Plants, Inc.; Chavez, Dario ( - University of Georgia; Clements, Jon ( – University of Massachusetts; Cline, John ( - University of Guelph, Ontario; Coneva, Elina ( – Auburn University; Cowgill, Win ( – Rutgers University; Crassweller, Rob ( – Pennsylvania State University; Einhorn, Todd ( – Michigan State University; Elkins, Rachel ( – University of California; Fallahi, Esmaeil ( – University of Idaho; Faruch, Macarena ( - University of Maryland; Fazio, Gennaro ( – USDA-ARS, Geneva, NY; Filion, Vicky ( – Recupom (Quebec, Canada); Fleck, Chuck ( – Sierra Gold Nurseries; Galimba, Kelsey ( – Oregon State University; Gonzalez, Luis ( – Cornell University; Hoover, Emily ( - University of Minnesota Irish-Brown, Amy ( - Michigan State University Extension; Kalcsits, Lee ( – Washington State University; Krupa, Jim ( - University of Massachusetts; Lang, Gregory ( – Michigan State University; Mahdavi, Shahla "Sara" ( – University of Idaho; Marini, Richard ( - Pennsylvania State University; Miller, Diane ( – Ohio State University; Minas, Ioannis ( – Colorado State University; Miranda Sazo, Mario ( – Cornell University; Muehlbauer, Megan (muehlbauer@njaes.rutgers) – Rutgers, The State University; Musacchi, Stefano ( –Washington State University; Parker, Mike ( - North Carolina State University; Peck, Gregory ( – Cornell University; Reighard, Gregory ( – Clemson University; Robinson, Terence ( - Cornell University; Russell, Cassandra ( - Ontario Ministry of Agriculture and Food; Serra, Sara ( - Washington State University; Shaffer, Carolyn ( – University of California; Shane, Bill ( – Michigan State University; Sherif, Sherif ( – Virginia Tech; Smith, Brent ( – TRECO Nursery; Stonaker, Frank ( – Colorado State University; Teh, Soon Li ( – Washington State University; Tetreault Garneau, Laurence ( - Recupom (Quebec, Canada); Valverdi, Nadia A. ( – Washington State University; Waite, Jessica ( - USDA-ARS Wenatchee; Warmund, Michele ( - University of Missouri; Wiepz, Rebecca ( - University of Wisconsin, Madison; Wolfe, Dwight ( – University of Kentucky; Xu, Hao ( - Agriculture and Agri-Food Canada (Summerland, BC; Yao, Shengrui ( - University of New Mexico; Yoder, Keith ( - Virginia Tech


Accomplishments: Apple, peach, and cherry rootstocks obtained from breeding programs in  the US, Canada, UK, France, Germany, Poland, Russia, New Zealand and Japan have been evaluated in the multi-state trials. NC-140 members and rootstock breeders have partnered with a commercial plant tissue culture company and traditional fruit tree nurseries to rapidly propagate rootstocks for evaluation in multistate trials. This collaborative effort has reduced the time to produce rootstocks for trial by more than 5 years.

Short-term Outcomes: After 5 years the Organic Apple Rootstock Trial has revealed some of the difficulties associated with organic apple production. Issues include inability to maintain soil nitrogen levels for adequate tree growth, difficulty controlling weeds and some insect pests, and lack of fruit thinning techniques. Vigorous rootstocks will likely be required for organic orchards. 

At sites with outbreaks of fire blight, apple trees on Geneva rootstocks and B.9 survived better than trees on commonly used Malling rootstocks.

In the southeastern states, peach trees on RootPack had poor survival and Guardian rootstock is being recommended for sites with a history of peach tree short life.

B.9 apple rootstock is widely planted because it is resistant to fire blight, but it lacks adequate vigor for some new weak-growing cultivars, such as ‘Honeycrisp’ and ‘Evercrisp’.

Outputs: Results from NC-140 trials are the primary source of information used to develop recommendations for rootstocks, orchard systems, and tree training/pruning for North American deciduous tree fruits. Most recommendations in state tree fruit production guides, as well as information provided by tree fruit nurseries, are based on results from NC-140 trials. Commercial tree fruit nurseries also rely on NC-140 results while making rootstock decisions.

In 2020, NC-140 members disseminated results related to the project by publishing 2 books, 33 refereed papers, 3 extension fact sheets, 21 popular articles, and made 14 presentations to scientific organizations, and 49 outreach presentations.

NC-140 members leveraged more than $12.7 million dollars to fund research related to the project. 


  • The early yields and labor efficiencies of novel high-density, precision-oriented, “fruiting wall” training systems, utilizing vigor-controlling rootstocks that contributed to increased apple and sweet cherry production across North America (as well as worldwide) is also promising for stone fruits like peaches and nectarines, particularly considering increasing problems with labor availability and/or expense.
  • Two 10-year multi-location apple rootstock trials were completed, and results were published. In general, trees on B.10, G.11, G.41 were similar in size to, but more productive than trees on the most widely planted dwarfing rootstock, M.9 NAKBT333. The rootstock CG.4214 was very productive and slightly more vigorous than M.9 NAKBT333. Rootstocks from the Geneva (G) and Budagovski (B) breeding programs will likely replace the Malling rootstocks within a decade.
  • A 9-year multi-location peach rootstock trial was completed, and results were published. Data suggest that rootstock vigor and productivity can be assessed after 5 years, but tree survival requires 4 or 5 additional years. In general, interspecific Prunus hybrid rootstocks did not perform better than peach ( persica) rootstocks. However, peach rootstocks did not perform well on high pH soils.
  • Data from 8 multi-location rootstock trials were used to show that site is an important factor influencing rootsucker development. Three different fruit tree species consistently produced more rootsuckers in UT, PA, KY, and SC than in BC and ONT.
  • Rootstock x site interaction was evaluated with 8 different stability analyses using data from 2 apple rootstock trials. Results varied depending on method used and variable being studied. In general, M.26, G.16, G.41, and G.935 were less stable and responded to the site conditions more than M.9 NAKBT337 and B.9.
  • After 8 years results from the Pear Orchard Systems trial indicate that the combination of tree training/spacing/rootstock is critical to achieve high productivity and fruit quality and it is necessary to continue pear trials for at least 10 years.
  • Results from several states indicate that rootstock influences fruit maturity date and the severity of bitter pit after storage.
  • For the first time, a complete range of vigor-controlling peach rootstocks are being evaluated in coordinated multi-state trials.
  • Controlled freezing experiments in MO and CO indicate that rootstock can influence the freezing tolerance of peach flower buds. Buds on trees on Lovel were more cold-tolerant than on the semi-dwarf rootstocks RootPac 40 and Controller 6.



  1. The reports, presentations, and videos associated with NC-140 cherry, apple, and stone fruit rootstock research and extension ( have become a widespread informational resource for fruit growers throughout the United States as well as the world.
  2. While establishing new orchards, growers in most states are relying on recommendations based on results from NC-140 trials. In NJ, most of the 511 acres of apples planted in the past 8 years used rootstocks and training systems recommended by NC-140 members. Nova Scotia growers have adopted G.935 and G.202 apple rootstocks to replace the Malling rootstocks. Several Kentucky apple growers have adopted high density planting systems using the new Geneva rootstocks. In 2019 Massachusetts growers planted 150 acres of trees on dwarfing rootstocks based on NC-140 results. Grower responding to surveys reported that in newer plantings pruning and harvest labor declined by 50%, fruit quality and size increased by 20%, profit increased by 50%, and due to smaller canopies, pesticide use declined by 70%. In the southeast Guardian peach rootstock, is being planted on sites with a history of peach tree short life. Ohio apple growers are using B.9 rootstock because it is resistant to fire blight.
  3. In Colorado, the peach rootstock Krymsk®86 performed well on high pH soils and is being recommended to the industry.
  4. In NY, the high-density trials with dwarfing rootstocks have stimulated growers to expand acreages of sweet cherry and pears.
  5. The eXtension apples community of practice was developed by NC-140 members to archive information about apple rootstocks and cultivars for the general public. In 2020 the website was transitioned to a new platform and NC-140 members will maintain and update the content


Log Out ?

Are you sure you want to log out?

Press No if you want to continue work. Press Yes to logout current user.

Report a Bug
Report a Bug

Describe your bug clearly, including the steps you used to create it.