Weed Control and Peanut (Arachis hypogaea L.) Response to AcetochlorAlone and in Combination with Various Herbicides

摘要

Acetochlor, a chloroacetamide herbicide, isnow registered for preplant (PPI), preemergence(PRE), and postemergence (POST) application inpeanut. Field research was conducted during 2011and 2012 in Georgia and North Carolina todetermine peanut response and weed control byacetochlor compared with S-metolachlor aloneand in programs with other herbicides. In weedfreeexperiments, peanut tolerance to acetochlor(1.26 and 2.52 kg ai/ha) and S-metolachlor (1.42kg ai/ha) were evaluated when applied PPI, PRE,early postemergence (EPOST), or POST. Peanuttolerance to acetochlor was similar to S-metolachlorwith no negative impact of either herbicideon peanut yield compared with non-treatedpeanut in absence of weed interference. Whenapplied PRE, acetochlor controlled Palmer amaranth,pitted morningglory, sicklepod, and Texasmillet similarly to S-metolachlor while control ofbroadleaf signalgrass was greater with S-metolachlor.Weed control programs containing EPOSTand/or POST applications of herbicides followingPRE herbicides provided the best overall weedcontrol but did not affect yellow nutsedge controlregardless of whether acetochlor or S-metolachlorwere applied. Herbicide programs including PRE,EPOST, and POST herbicides most often resultedin the greatest yields. There was no difference inpeanut yield regardless of the presence of acetochloror S-metolachlor in a comprehensiveherbicide program.