Cover crop termination timings and methods effect on cotton (Gossypium hirsutum L.) development and yield

Abstract

Cover crops have been promoted for use in agricultural systems due to both environmental and economic opportunities. Cotton (Gossypium hirsutum L.) growers in West Tennessee faced challenges in 2015 and 2016 with cover crop termination management which resulted in failed cotton stands. The objective of this experiment was to determine effects of cover crop termination timing and method on cotton emergence, development, and yield. Field experiments were conducted from 2018 to 2020 in both small plot and on‐farm scenarios across West Tennessee. Cover crop termination timings consisted of an at‐planting termination, 3 weeks prior to planting, and both a broadcast and furrow‐strip termination 6 weeks prior to planting. The cover crop termination methods consisted of chemical termination, mechanical termination, and chemical + mechanical termination. At‐planting termination reduced emergence by 25% and delayed maturity of 65% of the stand relative to a 6‐week broadcast termination. Mechanical termination reduced emergence by 26% and delayed maturity of 26% of the stand relative to the chemical and chemical plus mechanical termination treatments. Thrips injury ratings were greater in cotton following a chemical + mechanical termination of the cover crop. Damage from three‐cornered alfalfa hoppers (Sissistilus festinus) was less prevalent in cotton following cover crops terminated 6 weeks prior to planting in a broadcast method compared to other timings. While early season effects were observed, end‐of‐season yield differences were not noted. Still, producers in short season environments should be aware of the higher level of risk associated with at‐planting terminations or terminations.

The Potential of Cover Crops for Weed Management: A Sole Tool or Component of an Integrated Weed Management System?

“…For example, in an annual crop system in central Italy, a study compared the termination of cover crops at different times with a roller-crimper and glyphosate applications and observed that the sunflower ( Helianthus annuus ) yield was similar between the two systems when the cover crop was rolled late but not when it was rolled at an earlier stage of the cover crop and hence, the authors suggested that early termination of cover crops with a roller-crimper may have to be combined with glyphosate applications [ 41 ]. A study compared the chemical, mechanical, and chemical + mechanical termination methods of cover crop termination and their effect on cotton ( Gossypium hirsutum ) emergence and yield, and reported some differences in the crop emergence but no effect on yield [ 42 ]. Another study compared two different mechanical methods of cover crop termination on mulch, weed cover and nitrogen but not on crop yield [ 43 ].…”

Herbicide programs, cropping sequences, and tillage-types: a systems approach for managing Amaranthus palmeri in dicamba-resistant cotton

“…A. palmeri has the ability to evolve resistance to a full dose of dicamba in three generations when exposed to sub-lethal doses (Tehranchian et al, 2017), and, agreeing with that, reduced control of A. palmeri was observed in East Texas in a grower field with dicamba-only use history from the past 3 years (S. Nolte, personal communication, January 11, 2023). On the other hand, nonchemical strategies like cover crops (Wiggins et al, 2017;Palhano et al, 2018;Denton et al, 2023), crop rotations (Ball, 1992;Liebman and Dyck, 1993;Martin and Felton, 1993), and tillage practices (Refsell and Hartzler, 2009;Farmer et al, 2017) can influence A. palmeri germination and its composition in the weed communities. When combined with herbicide programs, they can be effective in managing GR A. palmeri (Aulakh et al, 2012;Aulakh et al, 2013).…”