Differential response of corn (Zea mays L.) to postemergence application of CGA-136872 at different growth stages

Abstract

CGA-136872 injured corn more when applied at the 5-leaf stage than when applied at the 7- and 9-leaf stage of corn. Symptoms of herbicide phytotoxicity were primarily stunting and chlorosis. Most injury occurred with high rates (400 g ai/ha) and appeared during the first two weeks following treatment. At five weeks after treatment, corn recovery from injury was complete and no yield reduction was recorded. Yield loss occurred in the weedy check, due to competition with johnson grass (Sorghum halepense (L.) Pers.), giant foxtail (Setaria faberi Herrn.), common lambsquarters (Chenopodium album L.) and redroot pigweed (Amaranthus retroflexus L).

Keywords

• Sulfonylurea herbicide
• Application timing
• Phytotoxicity