Factors Influencing Corn (<i>Zea mays</i>) Tolerance to Trifluralin

Abstract

Corn ( Zea mays L.) can be injured by carry-over of trifluralin [2,6-dinitro- N,N -dipropyl-4-(trifluoromethyl) benzenamine] in the soil from one crop year to the next. Factors influencing corn tolerance to carry-over concentrations of trifluralin in the soil were studied in controlled-environment chambers and greenhouse experiments. For several hybrids, greater injury occurred at low than at high temperatures. This injury was especially evident for ‘Pioneer 3320’ and ‘Pioneer 3572’ when the soil moisture was at 100% field capacity. Addition of phosphorus fertilizer appeared to have no influence upon trifluralin injury but did interact with alachlor [2-chloro- N -(2,6-diethylphenyl)- N -(methoxymethyl)acetamide]. Alachlor plus trifluralin injured corn in an apparently additive manner. Significant differences were found in genetic tolerance of corn to trifluralin within a group of hybrids. Tolerance of specific hybrids to trifluralin was altered by environmental conditions.