The use of reduced tillage-high residue crop rotation systems for the sandyland areas of the Texas Southern High Plains offers potential for solving some of the problems associated with conventional tillage continuous cotton production. These reduced tillage systems can increase yields, decrease production costs, and reduce soil erosion. New weed control programs must be developed for use in place of traditional preplant incorporated herbicides and tillage operations.

Studies were established near Brownfield, Texas in 1986 to evaluate cotton injury and weed control from preemergence herbicide applications made to cotton planted in sorghum stubble. Treatments included methazole, dipropetryn, prometryne, EL 107, metolachlor, diuron, and metolachlor combinations. All treatments were followed by sprinkler irrigation. Effective pigweed control was achieved with methazole, dipropetryn, EL 107, and metolachlor combinations with dipropetryn, prometryn, and EL 107. Effective volunteer sorghum control was achieved only with the highest rates of methazole and dipropetryn. Significant cotton injury was observed from metalachlor (alone or in combinations) and the highest rate of methazole. Excellent cotton yields resulted from applications of dipropetryn at 4.4 kg/ha where excellent season-long control of pigweed and volunteer sorghum was achieved with no crop injury.