Weed Management in Peanut (Arachis hypogaea) with Pyridate and SAN 582 Systems1

Abstract

Field studies were conducted near Archer, FL, and Vienna, GA, in 1995 and 1996 to investigate pyridate and SAN 582 for weed management in peanut. At Archer, pyridate plus 2,4-DB applied 3 wk after emergence resulted in 75, 72, 59, and 85% early-season control of yellow nutsedge, Florida beggarweed, hairy indigo, and sicklepod, respectively. In Vienna, pyridate plus 2,4-DB resulted in 87 and 55% early-season control of yellow nutsedge and Florida beggarweed, respectively. At both Archer and Vienna, SAN 582 applied preplant incorporated prior to pyridate postemergence (POST) increased control of yellow nutsedge, Florida beggarweed, and hairy indigo; however, peanut yield was not improved. In greenhouse studies, pyridate plus 2,4-DB controlled prickly sida, common cocklebur, and ivyleaf morningglory. Reduced weed control was observed in greenhouse studies when SAN 582 was added to the pyridate plus 2,4-DB POST tank mix.Nomenclature: Pyridate; SAN 582 (proposed common name dimethenamid), 2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N-(2,4-dimethyl-thien-3-yl)-acetamide; 2,4-DB; common cocklebur, Xanthium strumarium L. #3 XANST; Florida beggarweed, Desmodium tortuosum (Sw.) DC. # DEDTO; hairy indigo, Indigofera hirsuta Harvey # INDHI; ivyleaf morningglory, Ipomoea hederaceae (L.) Jacq. # IPOHE; prickly sida, Sida spinosa L. # SIDSP; sicklepod, Senna obtusifolia (L.) Irwin et Barneby # CASOB; yellow nutsedge, Cyperus esculentus L. # CYPES; peanut, Arachis hypogaea L. ‘GK-7’, ‘Marc III’, ‘Sunoleic 95R’, ‘Sunrunner’.Additional index words: Application timing.Abbreviations: NIS, nonionic surfactant; PPI, preplant incorporated; PRE, preemergence; POST, postemergence; WAE, weeks after emergence; WAT, weeks after treatment.