Field Corn Response to Diclosulam

Abstract

Crop rotation restrictions often limit the use of diclosulam in peanut (Arachis hypogaea L.). Research was conducted in 2013 and 2014 in Georgia to determine the response of field corn (Zea mays L.) to preemergence (PRE) applications of diclosulam with the intent of simulating carryover from applications made to a previous peanut crop. Diclosulam was applied at 0, 0.0008, 0.0015, 0.003, 0.006, 0.012, 0.024, and 0.047 lb a.i./acre. The normal use rate of diclosulam is 0.024 lb a.i./acre. Corn injury, stand loss, and yield loss increased with diclosulam rate. Diclosulam at 0.0008 lb a.i./acre caused <10% corn injury and <2% plant stand or yield loss. These results suggest that field corn could be safely planted after a field dissipation rate of five half‐lives. The reported half‐life of diclosulam is 13 to 43 days. Thus, it is likely that the field corn rotation restriction could be reduced in the Southeast where corn is grown in warm climates on coarse‐textured soils using supplemental irrigation, which help contribute to optimum microbial degradation of herbicides.