Control of Acetolactate Synthase–Resistant Shattercane (Sorghum Bicolor) in Field Corn with Kih-485

Abstract

Experiments were conducted in 2004 and 2005 in Virginia to evaluate KIH-485 for shattercane control. KIH-485 was applied to glyphosate-resistant corn at three rates (166, 209, and 250 g ai/ha) and two timings (preemergence [PRE] and postemergence [POST]) and compared to standard rates of S-metolachlor, acetochlor, and pendimethalin. PRE treatments were applied alone, while POST treatments were combined with 1,121 g ai/ha of glyphosate. A single POST application of glyphosate, a nontreated weedy control (WC), and a weed-free control (WFC) were also evaluated. In 2004, at 1 mo after planting (MAP), shattercane was controlled 73, 86, and 93% with the three PRE treatments of KIH-485 compared to only 50, 49, and 48% control with S-metolachlor, acetochlor, and pendimethalin, respectively. Similar levels of shattercane control were also observed with these treatments at 1 MAP in 2005. In both years at 4 MAP, KIH-485 combined with glyphosate applied POST controlled shattercane 96% or greater. However, when glyphosate was combined with S-metolachlor, acetochlor, or pendimethalin, shattercane control was less than 88% in either year. Corn yields with POST applications of KIH-485 plus glyphosate were equivalent to yield from the WFC and greater than yield from any PRE treatment. Early-season shattercane control was promising with KIH-485; however, season-long control only occurred when KIH-485 was applied POST in combination with glyphosate.

Peanut Tolerance to Pyroxasulfone

“…Pyroxasulfone provides no POST weed control activity. However, in other crops, the inclusion of pyroxasulfone in combination with POST herbicides is a strategy to enhance the residual control of susceptible weeds (King et al 2007;King and Garcia 2008). In peanut, this POST use pattern could be an effective means for controlling weeds with season-long emergence patterns, especially species that are difficult to control with other management tools such as Benghal dayflower and ALS-resistant Palmer amaranth.…”

“…Pyroxasulfone, formerly KIH-485, is a new broad-spectrum herbicide being developed for preemergence (PRE) (King and Garcia 2008;King et al 2007;Geier et al 2006;Knezevic et al 2009;and Steele et al 2005). From this list, Palmer amaranth and Texas millet are of particular interest since these are two of the most common and troublesome weeds of peanut (Webster 2009).…”

Studies on the inhibition of plant very-long-chain fatty acid elongase by a novel herbicide, pyroxasulfone

“…In this study, the reaction mixture contained 20 ml microsomal suspension, 5 ml of 20 mM NADH, 5 ml of 20 mM NADPH, 10 ml of 200 mM [2-14 C]-malonyl-CoA, 3 ml pyroxasulfone in acetone solution, 5 ml of 2 mM C24 : 0-CoA and H 2 O to 60 ml volume. The reaction mixture except for [2-14 C]-malonyl-CoA was pre-incubated for various time intervals at 30°C, and then the reaction was started by the addition of [2][3][4][5][6][7][8][9][10][11][12][13][14] C] malonyl-CoA. In the reaction without pre-incubation, microsomal suspension was added to the reaction mixture except for the microsomal fraction and then the reaction was started.…”

“…1,[8][9][10][11] This herbicide provides good efficacy on both grass and broadleaf weeds. In comparison with other currently available pre-emergence herbicides for use in wheat, pyroxasulfone at the field application rate of 100 g a.i./ha provides efficient control of both herbicide-resistant and susceptible annual ryegrass populations.…”

Role of metabolism in the selectivity of a herbicide, pyroxasulfone, between wheat and rigid ryegrass seedlings

“…1,[8][9][10][11] This herbicide is effective on both grass and broadleaf weeds. In comparison with other currently available pre-emergence herbicides for wheat, application of pyroxasulfone at a rate of 100 g ai/ha provides an efficient control of both herbicide-resistant and susceptible annual ryegrass populations.…”