Effect of Paraquat on Yield and Market Grade of Peanut (Arachis hypogaea) Genotypes

Abstract

Experiments were conducted for two years at one location and one year at a second location to determine the effects of paraquat on a range of peanut genotypes. Paraquat caused yield reductions of most Valencia-, Spanish-, and runner-market types as compared with hand-weeded checks. Virginia-market types were less affected by paraquat treatment. Most grade characteristics were adversely affected by paraquat. Because the paraquat treatments increased the proportion of other kernels, the herbicide may be affecting yield and grade by delaying maturity.

Response of Eight Peanut (Arachis hypogaea L.) Cultivars to the Herbicide AC 263,222

“…1, and sound split kernels make up TSMK, but these reductions were not evident in these other grade components (medium, No.1, or sound splits). Previous research has shown that paraquat reduced ELK of NC 7 and Florigiant, both virginia market types (12). TSMK was influenced only bycultivar ( Table 2).…”

“…Because herbicide-induced yield differences were not observed, given additional time for maturity, AC 263,222-treated peanut may grade similar to nontreated peanut. Knauft et al (12) noted similar results from paraquat application and attributed grade differences to method of maturity sampling from nontreated border peanut. Other herbicides have been shown to effect peanut yield and pod development (11).…”

“…However, research by Wehtje et al (16) reported that cultivars Florunner, NC 7, Southern Runner, and Sunrunner did not exhibit differential sensitivity to a single paraquat application at 0.14 kg ai ha-l . Later research by Knauft et al (12) reported that two paraquat applications at 0.14 kg ha' reduced yields of Florunner, Southern Runner, and Sunrunner. Differential response of peanut cultivars also has been reported with chlorimuron [2-[[[[(4-chloro-6- (10) reported no differential yield responses ofFlorunner, NC 7, or Southern Runner to multiple herbicide applications, but canopy widths were affected.…”

“…Since the 1970s, Florunner has been the predominant cultivar. However, recent hectarage increases in other runner cultivars, and production of virginia-type cultivars in regions previously dominated by runners has occurred (7,12). Therefore, the objective of this research was to evaluate the response of five runner and three virginia peanut cultivars to AC 263,222.…”

Peanut Response to Postemergence Application of Pyroxasulfone

“…Following application of paraquat, peanut foliage becomes stunted and necrotic. Peanut tolerance to paraquat or in mixture with bentazon and/or acifluorfen has been thoroughly studied (Carley et al 2009;Grichar and Dotray 2012;Johnson et al 1993;Knauft et al 1990;Tubbs et al 2010;Wehtje et al 1991;Wilcut et al 1994). Bentazon tank-mixed with paraquat has been documented to reduce paraquat injury in peanut (Wehtje et al 1992).…”