Agronomy and Crop Sciences Commons^™

Soybean Row Spacing And Weed Emergence Time Influence Weed Competitiveness And Competitive Indices, Shawn M. Hock, Stevan Z. Knezevic, Alex Martin, John L. Lindquist

John L. Lindquist

Weed competitiveness can be quantified with the concept of competitive index (CI), a relative scale of weed competitiveness. Field studies were conducted in 2002 and 2003 in northeastern and southeastern Nebraska to evaluate the influence of soybean row spacing and relative weed emergence time on the competitiveness of major weed species in soybean. Ten weed species were seeded in soybean spaced 19 and 76 cm apart at the planting, emergence, and first trifoliate leaf stages of soybean. Total weed dry matter (TDM), weed plant volume, and percent soybean yield loss were arbitrarily selected as a base for determining the CI …