Abstract: Glyphosate was compared with other commonly used corn herbicides at three locations in Kentucky in 1998 and 1999. Sequential glyphosate treatments provided greater than 87% control of common cocklebur, ivyleaf morningglory, common lambsquarters, and giant ragweed. Control of these species with glyphosate treatments was similar to the control with atrazine plus other postemergence (POST) herbicides. Generally, treatments containing s-triazines and chloracetamides applied to the soil surface were not as effective as sequential glyphosate or atrazine plus POST herbicides. Corn yield was not significantly different at any location or for any year, whereas differences in net return occurred at one location in 1998.
Nomenclature: Atrazine; chloracetamides; glyphosate; s-triazines; common cocklebur, Xanthium strumarium L. #3 XANST; common lambsquarters, Chenopodium album L. # CHEAL; giant ragweed, Ambrosia trifida L. # AMBTR; ivyleaf morningglory, Ipomoea hederacea L. Jacq. # IPOHE; corn, Zea mays L. ‘DeKalb 626RR’.
Additional index words: Acetochlor, dicamba, Digitaria sanguinalis L. Scop. DIGSA, dimethenamid, giant foxtail, large crabgrass, 1-(4-methoxy-6-methyl-triazin-2-yl)-3-[2-(3,3,3-trifluoropropyl)-phenylsulfonyl]-urea, metolachlor, net return, primisulfuron, prosulfuron, Roundup Ready® corn, Setaria faberi Herrm. SETFA, simazine.
Abbreviations: ASN, as needed; MP, mid-postemergence; POST, postemergence; PRE, preemergence; REG, regrowth.