The Impact of Maturity and Genotype on Blend Performance in Group V and Group VII Soybean Cultivars

It has been hypothesized that the divergent maturity of blend components is a major factor leading to the positive blend responses sometimes noted in soybean [ Glycine max (L.) Merr.]. The objective of this study was to examine the association between cultivar maturity and blend performance in determinate soybean. Eight purelines (four from maturity group [MG] V and VII), and the 28 two‐way blend combinations of these purelines were evaluated for seed yield in eight North Carolina environments. Blend responses (expressed as a deviation of the blend yield from pure‐stand component average) were 0.1, 1.9, and 3.3% for MG V, intermaturity (MG V/ MG VII), and MG VII blends, respectively. The intermediate average response of the intermaturity (MG V/MG VII) blends is an indication that divergent maturity of the blend components has little effect on blend performance. This notion is further substantiated in that individual positive blend responses occurred more frequently in the MG VII blends than in the MG V/MG VII blends. Only the MG VII blend group showed a significant overall blend response (84 kg ha −1 ). The highest yielding MG V/MG VII blend, that of ‘Coker 237’ (MG VII) with ‘N77‐114’ (MG V), was composed of component cultivars that blended well even when no maturity factors were evident. We conclude that maturity differences may be incidental to better blend performance in determinate soybean. The range of individual blend responses was −9.7 to 9.1%, expressed as deviations from pureline component averages.