WEED INTERFERENCE AND WEED PROBLEMS IN LOUISIANA SWEETPOTATOES—A REVIEW

Abstract

High annual rainfall and frequent torrential deluges have always made weed control a tenuous affair in Louisiana. Herbicide leaching and soil erosion often take preemergence herbicides to the nether regions. Before the time of postemergent grass herbicides, frequent cultivation was the only method to try to salvage the sweetpotato crop when preemergence weed control was lost. For many years, the most serious weed problems were prickly sida, cocklebur, and purple nutsedge with occasional hotspots of morning-glory. However, due to the change in herbicides used, the species of problem weeds have shifted to rice flatsedge, yellow and purple nutsedge, carpetweed, and various pigweeds. Before the registration of Command herbicide for use in sweetpotatoes, many sweetpotato growers used herbicides that effectively controlled or suppressed the current problem weeds. With the widespread use of Command, prior problem weed species are effectively controlled, but these other problem weeds are released.