Bell Pepper and Weed Response to Dimethyl Disulfide plus Chloropicrin and Herbicide Systems

Abstract

Bell pepper producers are faced with the challenge of controlling weeds following the phase-out of methyl bromide (MBr). Numerous attempts have been made to find a single fumigant or herbicide to control a broad spectrum of weeds. Adequate weed control in bell pepper will likely require weed management systems utilizing both fumigant and herbicide options. A weed management system including the fumigant dimethyl disulfide (DMDS) plus chloropicrin (Pic) plus the herbicide napropamide prior to transplant followed byS-metolachlor POST may be necessary to replace MBr. Field experiments were conducted during 2010 and 2011 near Ty Ty, Georgia to determine bell pepper and weed response to DMDS plus Pic or in systems with napropamide and/orS-metolachlor. Bell pepper were not significantly injured by DMDS plus Pic or napropamide. Injury caused byS-metolachlor was transient and plants fully recovered by 4 weeks after treatment (WAT). Yellow nutsedge control 6 WAT using DMDS plus Pic applied at 468 or 560 L ha−1controlled yellow nutsedge 91 to 95%. Large crabgrass control 6 WAT was 92 to 100% when DMDS plus Pic was applied at 468 or 560 L ha−1with or without a(n) herbicide (S-metolachlor or napropamide). Palmer Amaranth control prior to harvest was 21, 64, and 85% using DMDS plus Pic at 374, 468, or 560 L ha−1, respectively. DMDS plus Pic applied at 468 or 560 L ha-1with napropamide followed byS-metolachlor POST gave 95 to 99% control of Palmer amaranth 6 WAT. Consistent weed control and optimum yields were obtained when DMDS plus Pic was used at 468 L ha−1plus napropamide beneath plastic mulch followed byS-metolachlor POST.