Weed control in crucifer crops with nitrogen fertilizers

Only one or two herbicides are available for selective weed control in crucifer crops (broccoli, cabbage, cauliflower, brussels sprouts). With the cancellation of nitrofen, a postemergence herbicide, growers have resorted to hand-weeding of several herbicide-resistant weeds, such as little mallow (Malva parviflora), shepherds-purse (Capsella bursa-pastoris), and hairy nightshade (Solanurn sarrachoides).