2013 ASHS Annual Conference

Organic agricultural production systems differ significantly from conventional systems in their management of soil nutrients, weeds, pests, and diseases. Concomitant with these differences in management systems, cultivars developed for organic systems can include traits that differ from cultivars bred for conventional systems. For example, genetic differences in root architecture and capacity for symbiotic relationships have been found to differ in crop breeding stocks developed for organic production systems, relative to breeding stocks targeted for conventional nutrient management. Accelerated seedling vigor, rapid plant growth, and greater leaf area are traits that promote early stand establishment and canopy closure, and consequently improved weed control for organic systems. The same pests and diseases diminish crop productivity in organic and conventional systems, but without pesticides, the urgency for the incorporation of effective genetic resistance is heightened for crops grown in organic production systems. Intra-varietal genetic diversity is being explored for variation in these traits that contribute to yield stability under the greater diversity of cropping systems that are found on organic farms. Marketers and consumers of organically grown vegetables and fruits often place a greater premium on flavor, nutritional value, and novelty, and this broad range of market demands has stimulated the incorporation of numerous traits into cultivars for organic production that are otherwise unfamiliar to most consumers. To meet these diverse production challenges and consumer expectations, plant breeders developing cultivars for organic systems have begun to draw upon the breadth of genetic diversity of the crops they breed. Continued success in breeding will rely upon screening diverse germplasm and incorporating novel traits that will then be selected under low input, organic management practices.  Funding Source: USDA–NIFA Award no. 2011-51300-30903 of the OREI (Organic Agric. Res. & Ext. Initiative)