Common cocklebur is a very competitive and difficult to control weed species in soybean production. Field research was conducted at Rosemount, MN, from 1989 to 1991 to evaluate reduced rates of bentazon applied broadcast or banded over the crop row in combination with interrow cultivation for common cocklebur control in soybean. Bentazon at 0.6 kg ai ha−1 applied in a 38-cm-wide band over the soybean row followed by two cultivations controlled almost 90% of the common cocklebur when environmental conditions were favorable, and the majority of the common cocklebur emerged prior to bentazon application. However, when precipitation was below normal prior to bentazon application and a high proportion of the common cocklebur emerged after the initial bentazon application, sequential bentazon treatments controlled more common cocklebur and resulted in greater soybean yields than combinations of bentazon plus cultivation. Differences in soybean yield were attributed to differences in common cocklebur control rather than injury from cultivation or bentazon.
