Weed Management in Southeastern Peanut with Diclosulam and Flumioxazin1

Field studies were conducted near Marianna, FL during 1999 and 2000 to evaluate weed control and peanut response to PPI treatments of diclosulam alone, PRE treatments of flumioxazin alone, and in systems with POST commercial standard herbicides. Diclosulam and flumioxazin alone did not control sicklepod. Paraquat plus bentazon plus 2,4-DB applied early POST fb chlorimuron plus 2,4-DB or imazapic controlled sicklepod and pitted morningglory at least 83%. These treatments were equal to or greater than diclosulam or flumioxazin with or without paraquat plus bentazon plus 2,4-DB, or the same system fb 2,4-DB mid POST. Peanut yield was similar when treated with diclosulam or flumioxazin fb the standard early POST (EPOST) system, flumioxazin alone, or imazapic alone. Peanut treated with diclosulam alone or paraquat plus bentazon plus 2,4-DB fb 2,4-DB yielded lower than other treatments because of late-emerging Florida beggarweed. Peanut treated with chlorimuron, regardless of which soil-applied herbicide was used, yielded less due to a longer period of interference from Florida beggarweed, sicklepod, and pitted morningglory because of the timing of chlorimuron application (60 d after planting). Nomenclature: Bentazon; chlorimuron; diclosulam; flumioxazin; imazapic; paraquat; 2,4-DB; Florida beggarweed, Desmodium tortuosum S. DC #3 DEDTO; pitted morningglory, Ipomoea lacunosa L. # IPOLA; sicklepod, Senna obtusifolia (L.) Irwin and Barneby # CASOB; peanut, Arachis hypogaea L. ‘Georgia Green’. Additional index words: Bentazon, chlorimuron, imazapic, paraquat, 2,4-DB, peanut, Arachis hypogaea L. ‘Georgia Green’. Abbreviations: ALS, acetolactase synthase; EPOST, early postermergence; fb, followed by; WAP, weeks after planting.