Yield of Cool‐Season Soybean Lines Differing in Pubescence Color and Density

Abstract

AbstractSoybean [Glycine max (L.) Merr.] pubescence color may affect yield in cool‐season soybean growing areas. The objective of this research was to examine the interaction of tawny (T) and gray (G) pubescence color with dense (D) and normal (N) pubescence density on seed yield. Lines differing in pubescence color and density were created from crosses with eight soybean cultivars adapted to Maturity Group 00 and 0 conditions. Within each cross, quadruplets were selected that had the four pubescence types: TD, TN, GD, and GN. These lines were evaluated for yield across 4 yr at Ottawa, Canada. Lines with gray pubescence had from 7.6 to 27.7% higher yields than those with tawny pubescence in years receiving >2664 crop heat units (CHU) during the growing season. In a year receiving <2664 CHU, soybean lines with tawny pubescence had 9.3% higher seed yields than those with gray pubescence. The interaction between pubescence color and seasonal temperature was similar among lines of diverse genetic background. Tawny lines with dense pubescence had from 3.1 to 10.6% higher yields than tawny lines with normal pubescence when the seasonal precipitation was <360 mm. In gray lines, changing pubescence density did not consistently affect seed yields. Soybean pubescence color did affect seed yield and should be considered when breeding for cool‐season regions.