Comparative assessment of early season soybean cultivars in organic and conventional production system for morphological and agronomic traits

Abstract

AbstractOrganic production systems differ from the conventional system, especially because of the insect pest, weed, disease, and nutrient management. Therefore, there has been a focus on increasing performance stability in soybean [Glycine max (L.) Merr.] cultivars specifically adapted for organic farms. The objective of this study was to conduct a comparative assessment of Maturity Group 0 soybean genotypes grown in both organic and conventional conditions for several traits important in the organic soybean production system, such as early season canopy development, root morphology, nodule production, and nutrient use efficiency. A soybean panel consisting of 33 cultivars was grown in four environments (two locations × two years) on an organic farm and conventional production system farm in Southern Ontario, Canada. Significant differences among genotypes were observed for root morphology and canopy development in the organic environment only. Early season canopy development, root length, nodule mass, and nutrient use efficiency were related to yield in both environments. In addition, yield rank correlations between genotypes in two locations were significant in 2014 (r = .57) and 2015 (r = .31), and some large crossover effects were observed in both tested years. The principal components analysis for these and other agronomic traits showed that resource acquisition traits such as canopy development, root length, and nodule mass were more closely related to yield in the organic system than nutrient use efficiency. Overall, the results of this study may be useful for soybean breeders interested in developing cultivars adapted to the organic production system.