Host plant specificity in soybean varieties

Abstract

In two field experiments including 25 soybean varieties inoculated with a mixed peat inoculant, the capacity for a efficient symbiosis with Rhizobium was evaluated by the nodule weight. There were found highly significant differences between varieties and interaction between locations and varieties. The varieties with poor nodulation (L-571, Hardee, Jackson and L-2006) had equally few nodules at the two locations while several other varieties, specially these with intermediate nodule weight varied with the locations. Differences in nodule weights where principally due to differences in nodule numbers. It was concluded that, in order to obtain highly productive soybean varieties which at the same time are efficient in nitrogen fixation, it is necessary to select them for this character as well.