Submitted to: Journal of American Pomological Society
Publication Type: Review Article
Publication Acceptance Date: 5/8/2012
Publication Date: 8/1/2012
Citation: Elkins, R., Bell, R.L., Einhorn, T. 2012. Needs assessment for future US pear rootstock directions based on the current state of pear production and rootstock research. Journal of American Pomological Society. 66:153-163. Interpretive Summary:
Technical Abstract: Pear acreage in the United States (U.S.) is declining due to lack of precocity and high cost of production. The U.S. pear industry currently lacks “modern” orchard systems characterized by compact trees that produce early, high yields of large, high quality fruit. Tall, shaded canopies are not economically sustainable and are at a competitive disadvantage for attracting and sustaining a labor supply. There is broad and deep consensus in the pear industry that developing size-controlling rootstocks is imperative to remain competitive nationally and globally. Currently, employed rootstocks in the U.S. are P. communis seedlings and clones, none of which achieve more than about a one-third size reduction, and P. betulifolia seedlings. Quince (C. oblonga), used with interstems in Europe and South America, is suitable only for ‘Comice’ in the U.S. Current evaluation trials rely on older U.S. and imported selections, and include the NC-140 Regional Rootstock Project and several individual programs in California, New York, Oregon and Washington states. A fundamental deficiency is the lack of a mature pear rootstock breeding program, despite access to the USDA-ARS National Crop Germplasm Repository (NCGR), which holds a major worldwide collection of Pyrus and related genera. International breeding programs focus on increasing yield efficiency, but also graft compatibility, fruit quality and size, high soil pH tolerance, winter hardiness, warm climate/low chilling adaptation, drought and salt tolerance, and resistance to fire blight, pear decline, and pear scab. An intensive planning and implementation effort is needed to develop the necessary contacts, collaborations, explorations, and importation logistics to acquire the most promising selections for propagation and testing. Basic research needs include effects of dwarfing rootstock on tree architecture and fruiting, underlying mechanisms of dwarfing unique to pear, inheritance of key traits, and selection of breeding criteria. Propagation and orchard systems have also been identified as major research needs. This assessment is a result of discussions with stakeholders at Root2Fruit SCRI Research Proposal workshops.