Palmer Amaranth (Amaranthus palmeri) and Velvetleaf (Abutilon theophrasti) Control in No-Tillage Conventional (Non–genetically engineered) Soybean Using Overlapping Residual Herbicide Programs. (9th October 2018)

• Record Type: Journal Article
• Authors: Sarangi, Debalin; Jhala, Amit J.
• Is Part Of: Weed technology. Volume 33:Number 1(2019)
• Page Start: 95
• Page End: 105
• Publication Date: 2018-10-09
• Subjects: Aaron Hager, University of Illinois; Chlorimuron-ethyl, -- flumioxazin, -- fluthiacet-methyl, -- fomesafen, -- pyroxasulfone, -- S-metolachlor, -- Palmer amaranth, Amaranthus palmeri S. Watson, -- velvetleaf, Abutilon theophrasti Medik, -- corn, Zea mays L., -- soybean, Glycine max (L.) Merr; Benefit–cost ratio, -- best management practices, -- economics, -- multiple sites of action, -- PRE followed by POST; Weeds -- Periodicals; Weeds -- Control -- Periodicals; 632.5
• DOI: 10.1017/wet.2018.78
• Languages: English
• ISSNs: 0890-037X

Abstract

Abstract: Due to depressed corn and soybean prices over the last few years in the United States, growers in Nebraska are showing interest in no-tillage (hereafter referred to as no-till) conventional (non–genetically engineered [non-GE]) soybean production. Due to the increasing number of herbicide-resistant weeds in the United States, weed control in no-till non-GE soybean using POST herbicides is a challenge. The objectives of this study were to compare PRE-only, PRE followed by (fb) POST, and PRE fb POST with residual (POST-WR) herbicide programs for Palmer amaranth and velvetleaf control and soybean injury and yield, as well as to estimate the gross profit margins and benefit–cost ratio of herbicide programs. A field experiment was conducted in 2016 and 2017 at Clay Center, NE. The PRE herbicides tested in this study resulted in ≥95% Palmer amaranth and velvetleaf control at 28 d after PRE (DAPRE). Averaged across the programs, the PRE-only program controlled Palmer amaranth 66%, whereas 86% and 97% control was obtained with the PRE fb POST and PRE fb POST-WR programs, respectively, at 28 d after POST (DAPOST). At 28 DAPOST, the PRE fb POST herbicide programs controlled velvetleaf 94%, whereas the PRE-only program resulted in 85% control. Mixing soil-residual herbicides with foliar-active POST programs did not improve velvetleaf control. Averaged across herbicide programs, PRE fb POST programs increased soybean yield by 10% and 41% in 2016 and 2017, respectively, over the PRE-only programs. Moreover, PRE fb POST-WR programs produced 7% and 40% higher soybean yield in 2016 and 2017, respectively, compared with the PRE fb POST programs. The gross profit margin (US$1, 184.3 ha −1 ) was highest under flumioxazin/pyroxasulfone (PRE) fb fluthiacet-methyl plus S -metolachlor/fomesafen (POST-WR) treatment; however, the benefit–cost ratio was highest (6.1) with the PRE-only program of flumioxazin/chlorimuron-ethyl.