Dicamba-Tolerant Soybean Combined Cover Crop to Control Palmer amaranth

• Published in: Weed technology Vol. 32; no. 2; pp. 109 - 115
• Main Authors: Montgomery, Garret B, McClure, Angela T, Hayes, Robert M, Walker, Forbes R, Senseman, Scott A, Steckel, Lawrence E
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 01.04.2018; Weed Science Society of America
• Subjects: Agricultural practices; Agricultural production; Amaranth; Amaranthus palmeri; Biomass; cover crop termination; Cover crops; crop yield; Crops; cultural weed control; Delay; dicamba; fomesafen; Glycine max; Glyphosate; Herbicides; Intervals; Legumes; mechanism of action; Mode of action; Planting; resistance management; Secale cereale; Soybeans; Triticum aestivum; Vicia villosa; Weed control; WEED MANAGEMENT-MAJOR CROPS; Weeds; Wheat; Winter; United States > US; Tennessee
• ISSN: 0890-037X; 1550-2740; 1550-2740
• DOI: 10.1017/wet.2017.96

A study was conducted to evaluate the response of glyphosate- and dicamba-tolerant (GDT) soybean and weed control from cover crop different termination intervals before and after soybean planting. Cover crop biomass was highest when terminated at planting, decreased with the 7- and 14-d preplant (DPP) and day-after-planting (DAP) timings, and again at the 14 DPP and DAP timings. Glyphosate + dicamba provided total control of cover crops by 21 DAP. Cover crop termination timing did not influence soybean population or yield. Palmer amaranth control at the 21 and 28 d after termination (DAT) was 97% to 99%. Differences in Palmer amaranth control were not detected among herbicide programs or termination intervals at the end of season rating, and all treatments provided ≥97% control. Although differences in Palmer amaranth control were not apparent at the end of the season, the delay in cover crop affected the number of days until 10-cm Palmer amaranth was present. When utilizing a wheat + hairy vetch cover crop in DGT soybeans, producers should delay cover crop termination until 11 to 14 DPP and make at least one POST application of glyphosate + dicamba + an additional herbicide mode of action (MOA) to maximize Palmer amaranth control and soybean yields. Nomenclature: Glyphosate; dicamba; fomesafen; Palmer amaranth, Amaranthus palmeri (S.) Wats.; hairy vetch, Vicia villosa Roth.; wheat, Triticum aestivum L.; soybean, Glycine max (L.) Merr.