Efficacy and crop response to glufosinate-based weed management in PAT-transformed sweet corn (Zea mays)

Field studies were conducted at Arlington, WI, in 1996 and 1997 and at Geor getown, DE, and LeSueur, MN, in 1997 to determine weed control efficacy, cr op injury, and yield response of PAT-transformed sweet corn to glufosinate- based weed management. Sequential applications of glufosinate 10 to 18 d ap art at 0.4 and 0.3 kg ai/ha controlled common lambsquarters, common ragweed , velvetleaf, wild-prose millet, and fall panicum 90% or better at all loca tions. Weed control varied little among 0.3, 0.3, or 0.3 and 0.3 (sequentia l) kg/ha glufosinate rates. Glufosinate applied alone, with, or following a trazine controlled velvetleaf 90% or greater but was less consistent on com mon ragweed and common lambsquarters (73 to 100%). Atrazine plus metolachlo r applied preemergence (PRE) and glufosinate applied alone postemergence (P OST) provided inconsistent wild-prose millet and fall panicum control (43 t o 99%). Metolachlor followed by glufosinate improved consistency of grass c ontrol (>76%). Glufosinate followed by cultivation provided 80% or greater control of velvetleaf and wild-prose millet. Glufosinate did not injure or delay maturity of PAT-transformed sweet corn. Sweet corn treated with,glufo sinate resulted in yields greater than or equal to the sweet corn that was hand-weeded or received a standard herbicide treatment.