asclepias on the field with young soybeans. lambsquarters soy sprouts on an unencidesed without herbicidefield. weed

asclepias field young soybeans lambsquarters soy sprouts unencidesed herbicidefield weed cover present agricultural death crop control soybean single nonresidual time farmers should intensify management critical period without fields organic farms transmit diseases pests cause problems harvesting dealing troublesome weeds where herbicides from affected prevent herbicideresistant spreading grass