Tuesday, November 6, 2007
142-7

Yield Response of Double-Cropped Soybean to Deficit Stands.

David Holshouser, Tidewater AREC, Virginia Tech, 6321 Holland Road, Suffolk, VA 23437

Soybean producers need to be aware of the potential yield loss from deficit stands and the cost of replanting. Gaps within rows and less-than-optimal plant populations contribute to yield loss. Information is lacking in double-cropped soybean. Therefore, the objective of this research was to determine the yield response of double-cropped soybean to deficit stands. Soybean was planted in 46-cm rows following wheat harvest to obtain target plant populations of 240, 340, 440, and 540 thousand plants per hectare. At two weeks after planting, 1-m long, equally-spaced gaps were established over 0, 20, 40 or 60% of the plot area. Yield dependencies on plant population within each gap treatment were tested with standard orthogonal polynomial coefficients to determine linear or quadratic trends and with non-linear techniques. From these data, the yield response of double-cropped soybean to deficit stands was determined.