Sweet potatoes are a long-season crop. Weed control during production can be difficult. Early-season competition from weeds is extremely critical. A major emphasis on control should be made during this period. Growers must plan a total weed control program that integrates mechanical and cultural methods with the use of herbicides.

At the present time, there are only four herbicides that provide preemergence control of weeds in sweet potato. Cultivation is also an effective way to manage weeds early in the season. Rolling cultivators either by themselves or behind hilling blades can uproot many annual weeds that have escaped the herbicide or have emerged since the last cultivation. Cultivation and hilling, while useful, disrupt the efficacy of soil-applied herbicides. Fusilade® may be applied at any time until 55 days of harvest, and Poast® or Select® may be applied up to 30 days of harvest to control emerged grass weeds. These herbicides do not provide preemergence control.

Herbicide performance depends on weather, irrigation, soil type, proper selection for weed species to be controlled, and accurate application and timing (Tables 1 and 2).

Tables