Herbicide Systems for Control of Horse Purslane (Trianthema portulacastrum L.), Smellmelon (Cucumis melo L.), and Palmer Amaranth (Amaranthus palmeri S. Wats) in Peanut

Abstract

Abstract Field studies were conducted during the 2003 through 2005 growing seasons to evaluate soil-applied herbicides alone or in combination with postemergence (POST) herbicides for horse purslane, smellmelon, and Palmer amaranth control in peanut. Pendimethalin alone applied preplant incorporated (PPI) failed to control any of the three weeds (< 70% control). Pendimethalin in combination with diclosulam, followed by imazethapyr applied preemergence (PRE), or followed by either acifluorfen or imazapic applied postemergence (POST) controlled all three weed species at least 80%. The soil-applied herbicides flumioxazin, imazethapyr, S-metolachlor, or dimethenamid applied alone failed to control horse purslane and smellmelon (< 75%). Pendimethalin controlled Palmer amaranth less than 42% while flumioxazin at 0.07 kg/ha or dimethenamid at 1.12 kg/ha controlled Palmer amaranth less than 75%. Imazethapyr alone or pendimethalin applied PPI followed by imazethapyr applied PRE or imazapic applied POST controlled Palmer amaranth at least 99%. Pendimethalin applied PPI was present in all herbicide systems that yielded greater than the untreated check. In addition, 80% or greater control of at least 2 of 3 weed species resulted in the highest yields, with the exception of pendimethalin followed by acifluorfen.