Peanut Tolerance to Pyroxasulfone

Abstract

Due to limited hectares and production in comparison to field corn, soybean, and wheat, commercial research and development efforts by major manufacturers for potential new peanut herbicides are minimal. Therefore, new herbicides developed for large hectare crops should be evaluated for potential use in peanut. Field trials were conducted in Ty Ty and Plains Georgia in 2007 and 2008 to evaluate the tolerance of peanut to PRE and POST applications of pyroxasulfone at five rates (0, 120, 240, 360, and 480 g ai/ha). Pyroxasulfone did not cause significant peanut injury at the Ty Ty location. In Plains, PRE applications of pyroxasulfone caused significant crop stunting, particularly at the 360 and 480 g/ha rates. In Ty Ty, PRE applications of pyroxasulfone also resulted in greater expression of tomato spotted wilt virus than POST applications. Peanut yields were not reduced by any rate or timing of pyroxasulfone. These results suggest that pyroxasulfone may have some potential to be utilized in peanut.Key Words: crop injury, tomato spotted wilt virus, yield.In 2010, peanut was planted on 522,000 ha in the U.S. (Anonymous 2011). In contrast, field corn, soybean, and wheat were planted on 36,000,000, 31,000,000, and 22,000,000 ha, respectively (Anonymous 2011). Consequently, commercial research and development efforts for new herbicides are focused in these crops and not in peanut Pyroxasulfone is an inhibitor of very-longchain-fatty acids and should be categorized within the K3 group of herbicides (Tanetani et al. 2009). Other common K3 herbicides include acetochlor, alachlor, butachlor, dimethenamid-p, flufenacet, Smetolachlor, and propachlor (Senseman 2007). Smetolachlor is frequently used in peanut for the control of various weeds including yellow nutsedge (Cyperus esculentus L.) and Benghal dayflower (Commelina benghalensis L.) (Grichar et al. 2001;Grichar et al. 2008;Prostko et al. 2005).Little information about the tolerance of legume crops to pyroxasulfone has been published in the literature. Although pyroxasulfone was initially targeted for PRE weed control in corn, soybean has shown good tolerance The soil type at the Ponder Research Station was a Tifton sand with 96% sand, 2% silt, 2% clay, 1.2% organic matter, and pH 6.0. The soil type at the Southwest Experiment Station was a Greenville sandy loam with 71% sand, 13% silt, 16% clay, 1% organic matter, and pH 6.0. Cultivars, planting dates, inverting, and harvest dates are presented in Table 1. Common production practices and Cooperative Extension recommendations were used at all times. Supplemental irrigation was applied as needed.Herbicide treatments were arranged in a factorial design that included two application timings (PRE or POST) and five pyroxasulfone rates (0, 120, 240, 360, and 480 g ai/ha). All treatments were replicated four times. PRE treatments were activated with irrigation within 48 hours of application. POST treatments of pyroxasulfone were applied between 44 and 51 days after peanut planting and included a non-ionic surfactant...

Peanut Response to Postemergence Application of Pyroxasulfone

“…Peanut yield was not influenced by pyroxasulfone rate or application timing (Tables 2 and 3). These results are similar to Prostko et al (2011), who reported excellent peanut tolerance to pyroxasulfone applied 44 to 51 days after emergence. These data provide evidence that pyroxasulfone may be applied throughout the peanut growing season with little concern of negative yield effects.…”

“…Similarly, pyroxasulfone, a preemergence (PRE) herbicide currently labeled for use in corn and soybean is being developed for use in wheat (Triticum aestivum L.) and sunflower (Helianthus annus L.). While research concerning peanut tolerance to pyroxasulfone is limited, Prostko et al (2011) reported excellent tolerance when it was applied POST at 44 to 51 days after emergence. Pyroxasulfone may potentially have utility in peanut but manufacturers may never explore this use without third party research efforts.…”

Peanut Cultivar Response to Preemergence Applications of Pyroxasulfone

“…Pyroxasulfone applied at 240 g ai/ha reduced yield to 6,640 kg/ha (7%) as compared to the non-treated control. Previously, Prostko et al (2011) did not observe yield loss following PRE application of pyroxasulfone in peanut. Peanut cultivar did influence peanut yield.…”

“…During 2013, pyroxasulfone applied at 240 g ai/ha resulted in greater stunting in 'Tifguard' than in 'Georgia-06G'. Prostko et al (2011) documented transient peanut stunting at one of two locations following pyroxasulfone applied PRE. Additionally, differential peanut cultivar response to herbicides has been observed in Virginia-and runner-type peanut cultivars (Jordan et al 1998;McLean et al 1994).…”

“…Previous research has determined that peanut is adequately tolerant to pyroxasulfone applied 44 to 51 days after emergence (Prostko et al 2011). Pyroxasulfone applied PRE to peanut has been documented to cause minimal early season stunting but no yield loss (Prostko et al 2011).…”