Irrigated and Non-Irrigated Peanut (Arachis hypogaea L.) Cultivar Response to Postemergence Paraquat Tank-Mixtures

Paraquat postemergence (POST) applied is often used to control broadleaf and grass weed species in peanut in the Southeast US. The objective of this study was to determine the effects of POST herbicide tank-mixtures including paraquat on vegetation, yield, and grade for runner-type peanut cultivars under irrigated and non-irrigated conditions. Two separate experiments (irrigated and non-irrigated) were conducted in 2016 and 2017 in Ty Ty and Plains Georgia. Georgia-06G, Georgia-14N, TUFRunner™ ‘511’, and FloRun™ ‘157’ cultivars were evaluated. Herbicide tank-mixtures included paraquat, paraquat plus acifluorfen plus bentazon, paraquat plus acifluorfen plus bentazon plus S-metolachlor, and paraquat plus acifluorfen plus bentazon plus acetochlor. Leaf burn, stunting injury, yield, and grade were evaluated. There were no interactions between herbicide and cultivar for all variables. Paraquat alone resulted in significantly greater foliar injury (3 DAT) than the other herbicide treatments for the irrigated (34 to 16%) and non-irrigated (28 to 15%) studies. Stunting for paraquat alone was noted at 15 and 35% for irrigated and non-irrigated, respectively. Similarly, in both studies, Georgia-06G and TUFRunner™ ‘511’ yielded 10 to 12% greater than Georgia-14N and FloRun™ ‘157’. Overall, the herbicide tank-mixtures did not have a negative effect on yield. With no interactions observed, these herbicide treatments can be used in conjunction with the given runner-type peanut cultivars in either irrigated or non-irrigated conditions without concern for excessive injury or decline in yield or grade.