To determine the effects of reduced herbicide application rates on grassy and broad-leaved weeds, diamondback moth, root maggot, and sclerotinia stem rot infestations. To determine the effects of reduced herbicide application on populations of natural enemies (predators and parasites) of root maggots and diamondback moth. To determine the level of weedy background that is most effective for reducing infestations of root maggots, diamondback moth, and sclerotinia stem rot, and for providing greatest economic returns for producers.