Wednesday, November 15, 2006
235-3

Yield Response of Double-Cropped Soybean to Deficit Stands.

David Holshouser, Virginia Tech -Tidewater AREC, 6321 Holland Rd., Suffolk, VA 23437, United States of America

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 following wheat harvest to obtain target plant populations of 100, 140, 180, and 220 thousand plants per acre.  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.