The Economics of Common Cocklebur Control in Soybean Production

The effects of common cocklebur (Xanthium pensylvanicum Wallr.) on soybean [Glycine max (L.) Merr.] yields, grades, and net returns were determined by regression analysis of data from 450 research plots from 1971 through 1973. Common cocklebur control from 0 to 100% was achieved by various combinations of preemergence and postemergence practices. Foreign matter in soybean seed samples was 0.7% with total common cocklebur control and 5.1% with no control. At least 70% control of common cocklebur was required to avoid deductions from gross harvested weights due to seed moisture levels exceeding 13%. Small discounts for damaged kernels occurred when common cocklebur control was less than 40%. With 100% common cocklebur control, the estimated US soybean grade was 1.3. Failure to control common cocklebur resulted in a predicted grade of 3.9. When adjusted for various weight discounts, soybean yields were 1170 kg/ha without control of common cocklebur and 1890 kg/ha for 100% control. Soybean yields were increased about 6% for each 10% increase in common cocklebur control. Net returns to land, management, and general farm overhead were $63/ha when common cocklebur was not controlled, and $119/ha with 95% control.