Temporal Importance of Greater Light Interception to Increased Yield in Narrow-Row Soybean

Increased light interception is considered the main factor explaining greater yield in narrow- compared to wide-row spacing in soybean [Glycine max (L.) Merr.]. Controversy exists, as to when during the growth cycle the greater ligh interception of the narrow rows has an enhancing effect on yield. The objectives of this study were to analyze crop grown rate and yield components to determine the importance of greater light interception during vegetative (E-R1), early reproductive (R1-R5), and late reproductive (R5-R7) periods to increased yield in narrow-row culture. Field studies were conducted during 1989 and 1990 at a late (July) planting date with Centennial' soybean (determinate, Maturity Group VI) at row spacings of 100, 75, 50 and 25 cm (...)