Field studies were conducted at four locations in North Carolina in 1998 and 1999 to evaluate a computer program, Herbicide Application Decision Support System (HADSS™), for weed management in peanut (Arachis hypogaea). Weed management systems included metolachlor or ethalfluralin preplant-incorporated (PPI) used alone or in combination with diclosulam preemergence (PRE) or flumioxazin PRE. These herbicide combinations were used alone, followed by (fb) postemergence (POST) herbicides recommended by HADSS™ or fb a standard POST program of paraquat plus bentazon early postemergence (EPOST) fb acifluorfen plus bentazon POST. The standard POST herbicide system and HADSS™ POST recommendations were also used without soil-applied herbicides. Ethalfluralin PPI alone controlled large crabgrass (Digitaria sanguinalis) better than metolachlor PPI. Combinations of metolachlor or ethalfluralin PPI with either diclosulam or flumioxazin PRE provided equivalent control of all weeds evaluated except yellow nutsedge (Cyperus esculentus). The addition of diclosulam or flumioxazin PRE to systems containing metolachlor or ethalfluralin PPI always improved control of ivyleaf morningglory (Ipomoea hederacea) and yellow nutsedge and improved yield and net returns in 15 of 16 comparisons where no POST herbicides were used. For systems that used diclosulam or flumioxazin PRE, the HADSS™ POST and standard POST herbicide systems improved yield in 4 of 12 and 2 of 12 comparisons, respectively, compared with similar systems that did not use diclosulam or flumioxazin. However, in systems using either HADSS™ POST or the standard POST system, yield was always improved when compared with metolachlor or ethalfluralin PPI alone. HADSS™ POST provided equal or higher weed control, peanut yield, and net returns when compared with the standard POST herbicide system.
Nomenclature: Acifluorfen; bentazon; ethalfluralin; metolachlor; paraquat; ivyleaf morningglory, Ipomoea hederacea (L.) Jacq. IPOHE; large crabgrass, Digitaria sanguinalis (L.) Scop. DIGSA; yellow nutsedge, Cyperus esculentus L. CYPES; peanut, Arachis hypogaea L. ‘NC 7’ and ‘NC 10C’.