Wheat Cultivar Performance on Certified Organic Fields in Minnesota and North Dakota

Abstract

Synthetic agrichemicals are used to minimize nutrient deficiencies and pests when developing and selecting modern small-grain cultivars. Some farmers believe that modern cultivars are not adapted to environments without these inputs, and old cultivars should be grown. Our objective was to determine the adaptability of spring wheat (Triticum aestivum L.) cultivars for production in certified organic environments. A single seed lot for 15 cultivars and two seed lots each for two others were used to establish 19 treatments evaluated for grain yield, protein content, kernel and volume weight, along with phenotypical growth traits on four certified organic fields in Minnesota and North Dakota in 2003 and 2004. The cultivars represented different development eras, but 11 were released since 1995. Interactions between environments and cultivars existed for the four grain parameters (P , 0.05), but some modern cultivars ranked high consistently for yield, protein content, and volume weight. For example, the modern cultivar Walworth produced an average of 500 kg ha 21 more grain than the highest yielding cultivar developed before 1970. Seedling vigor and other phenotypical growth traits did not explain consistent yield differences between cultivars. These results suggest that modern spring wheat cultivars are adapted to certified organic environments. The phenotypical growth traits considered in this study are not suited as primary selection criterion for cultivars in certified organic environments. P.M. Carr, North Dakota State Univ., Dickinson Res. Ext. Ctr., 1133 State Ave., Dickinson, ND 58601-3267; H.J. Kandel, Univ. Minnesota, Crookston Res. Ext. Ctr.,

Weed Community Dynamics and Suppression in Tilled and No-Tillage Transitional Organic Winter Rye–Soybean Systems

“…While his work shows that conventionally-bred lines can perform well under organic management, it does not indicate that conventionally-selected lines are the best for organic systems. Carr concludes that "modern cultivars of hard red spring wheat that were developed and selected using synthetic agrichemicals are adapted to environments under certified organic management" (Carr et al 2006). Stephen Jones, in his organic wheat breeding program at Washington State University, uses older varieties to identify and supply high-quality baking and milling traits that can then be used to improve disease-resistant modern varieties for organic production systems.…”

Developments in breeding cereals for organic agriculture

“…For highly heritable traits where selection can be imposed in the early stages on a single plant or small plot basis, indirect selection, i.e. selection in an environment different from the target environment, can even lead to higher selection efficiency than direct selection (Hill et al 1998 The selection strategies for low-input conditions imposed by Hänsel and Fleck (1990) and Spanakakis and Röbbelen (1990) have led to varieties adapted to OA in several European countries together with new conventional varieties that perform best in OA in the US (Carr et al 2006).…”

“…New genetic material from other farming systems has to be introduced continuously into OA in order not to lose genetic variability (Carr et al 2006). The highest possible variability of varieties for OA can be assured by extending the choice to varieties developed within all three breeding strategies, BFCA, BFOA and OPB.…”

Realized gains from selection for spring wheat grain yield are different in conventional and organically managed systems

“…Several studies report differences in the performance of wheat cultivars in organic and conventional management systems, with some cultivars better suited to organic management in northern North America (Carr et al 2006;Mason et al 2007c;Nass et al 2003). Przystalski et al (2008) found specific cultivars exhibiting cross-over interactions between management systems despite high genetic correlations between systems.…”