An equivalence of estimations on the plots of a soybean breeding nurse to estimations of yields in competitive variety trials of soybean

The relations between seed yields of soybean cultivars in the competitive variety trials (CVT) and traits of the parental lines in a breeding nurse (BN) were presented. The estimations of soybean cultivar yields in CVT (plural-row plots with replications) were compared with the estimations of yields of their parental lines in BN (one-row or double-row plots without replications). The results showed a lack of the relationship. The meanings of the correlation rates (from -0.494 to 0.117) were insignificant that point out inefficiency of a selection of the highly productive biotypes in small plots by a direct trait - seeds weight per a plot or yield. Quite the contrary, an essential positive connection between a harvesting index of the parental lines in BN and cultivar yields in CVT was revealed. The harvesting index is concluded to be important and possible for usage as a criterion for selection at soybean breeding for yield at a stage of small plots without protection rows and replications.