Peanut Cultivar Response to Preemergence Applications of Pyroxasulfone

Abstract

Pyroxasulfone is a residual herbicide developed for use in several agronomic crops such as corn (Zea mays L.), soybean (Glycine max L.), wheat (Triticum aestivum L.), and sunflower (Helianthus annuus L.). Pyroxasulfone provides effective preemergence (PRE) control of annual grasses and broadleaf weeds, but little is known about peanut cultivar tolerance. Therefore, field trials were conducted in Georgia during 2012 and 2013 to evaluate peanut cultivars 'Georgia-06G', 'Georgia Greener', and 'Tifguard' response to pyroxasulfone applied PRE at 0, 120, or 240 g ai/ ha. Greater stunting occurred during 2012 than 2013. Peanut stunting 10 days after planting (DAP) during 2012 and 2013 ranged from 38 to 55% and 3 to 11%, respectively. At 10 DAP, greater injury was observed in 'Tifguard' as compared to 'Georgia-06G' with pyroxasulfone at 120 g ai/ha. 'Georgia Greener' was injured more than 'Tifguard' following the 240 g ai/ha rate of pyroxasulfone. By 120 DAP, peanut had recovered substantially from stunting caused by PRE applications of pyroxasulfone with no cultivar interactions. Peanut yield was influenced by pyroxasulfone rate when applied PRE. Peanut yield was 7,140 kg/ha in treatments that did not include pyroxasulfone. Treatments that included pyroxasulfone at 120 g ai/ha yielded similar to treatments without pyroxasulfone. Peanut yield was reduced to 6,750 kg/ha (7%) following pyroxasulfone applied at 240 g ai/ha. When combined over pyroxasulfone rate, 'Georgia-06G' produced greater yields than the other cultivars.

Evaluating herbicide programs for peanut response and weed control

“…Eure et al. (2015) also observed greater peanut stunting as a result of pyroxasulfone in a year with greater rainfall. Although the initial injury with flumioxazin was greater in 2020, peanut recovered from injury and produced similar canopy to other herbicide treatments at 4 WA‐EPOST.…”

“…In addition, higher rainfall during the 2020 peanut season than in 2019 could have influenced the differences in peanut canopy growth. Eure et al (2015) also observed greater peanut stunting as a result of pyroxasulfone in a year with greater rainfall. Although the initial injury with flumioxazin was greater in 2020, peanut recovered from injury and produced similar canopy to other herbicide treatments at 4 WA-EPOST.…”

“…However, this study reported peanut injury and stunting with pyroxasulfone applied alone or in combination with flumioxazin. Eure et al (2015) reported a variable peanut response, where stunting ranged from 38 to 53% in one study year and from 3 to 11% in another year at 10 d after PRE pyroxasulfone. However, peanuts had recovered from injury by 120 d after treatment and did not exhibit substantial stunting.…”

A systematic review of chemical weed management in peanut (Arachis hypogaea) in the United States: challenges and opportunities

“…Pyroxasulfone is another chloroacetamide herbicide used to control grasses and small-seeded broadleaf weeds in peanut (Dotray et al 2018; Eure et al 2015) and is similar in activity to acetochlor, dimethenamid- P , and S -metolachlor. Pyroxasulfone has a similar weed control spectrum but has a higher specific activity, allowing for a much lower application rate compared with dimethenamid- P (Grichar et al 2019).…”

“…Pyroxasulfone has a similar weed control spectrum but has a higher specific activity, allowing for a much lower application rate compared with dimethenamid- P (Grichar et al 2019). Peanut generally has good tolerance to pyroxasulfone; however, preemergence applications caused 8% to 18% early-season peanut stunting (Eure et al 2015; Grichar et al 2019; Prostko et al 2011). Several factors, including rates, soil type, environmental conditions, and cultivars, may influence early-season stunting or injury, with greater stunting following preemergence applications in heavy soils under wet conditions (Prostko et al 2011).…”