%0 Journal Article
%T Late-Season Grass Weed Management with In-Crop and Post-Harvest Herbicides in Twin-Row Glyphosate-Resistant  Soybean
%A Krishna N. Reddy
%A Charles T. Bryson
%A Vijay K. Nandula
%J American Journal of Plant Sciences
%P 213-218
%@ 2158-2750
%D 2015
%I Scientific Research Publishing
%R 10.4236/ajps.2015.61024
%X Emergence of grasses late in the season has become a problem in glyphosate-resistant (GR) soybean production in the southern US. A 3-yr field study was conducted from 2011 to 2013 at Stoneville, MS to determine efficacy of post-harvest and pyroxasulfone-based in-crop herbicides on late-season grasses and yield in twin-row glyphosate-resistant soybean. Experiments were conducted in a split-plot arrangement of treatments in a randomized complete block design with fall herbicides (with and without pendimethalin at 1.12 kg ai ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> and paraquatat 0.84 kg ai ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span>) as main plots and in-crop herbicides as subplots with four replications. The six in-crop herbicide programs were: glyphosate applied early postemergence (EPOST) at 0.84 kg<span style=\"white-space:nowrap;\">，</span>aeha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> followed by (fb) glyphosate late postemergence (LPOST) at 0.84 kg<span style=\"white-space:nowrap;\">，</span>ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> with and without pyroxasulfone preemergence (PRE) applied at 0.18 kg ai ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span>, pyroxasulfone PRE fb glyphosate at 0.84 kg<span style=\"white-space:nowrap;\">，</span>ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> LPOST or glyphosate at 0.84 kg<span style=\"white-space:nowrap;\">，</span>ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> + S-metolachlor at 1.68 kg ai ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> EPOST, pyroxasulfone PRE fb S-meto- lachlor at 1.12 kg<span style=\"white-space:nowrap;\">，</span>ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> + fomesafen at 0.27 kg ai ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> EPOST fb clethodim at 0.14 kg ai ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span>, and a no-herbicide control. Browntop millet, Digitaria spp., and junglerice densities at 2 weeks after LPOST, grass weed dry biomass at harvest, and soybean yield were similar regardless of post- harvest herbicides in all three years. At 2 weeks after LPOST, browntop millet, Digitaria spp. and junglerice densities were greatly reduced in all five in-crop herbicide treatments compared with no herbicide plot in all three years. Grass weed dry biomass in no-herbicide plots was 3346, 6136, and 6916 kg<span style=\"white-space:nowrap;\">，</span>ha<span style=\"white-space:nowrap;\"><sup>-1</sup></span> in 2011, 2012, and 2013, respectively and
%K Browntop Millet
%K Digitaria spp.
%K Junglerice
%K S-Metolachlor
%K Pyroxasulfone
%K Soybean
%K Twin-Row
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53457