How to translate text using browser tools
14 February 2025 Effect of Fall- and Spring-Planted Cover Crops and Residual Herbicide on Emergence Dynamics of Glyphosate-Resistant Kochia (Bassia scoparia)
Sachin Dhanda, Vipan Kumar
Author Affiliations +
Abstract

Two separate field experiments were conducted during the 2021 to 2022 and 2022 to 2023 growing seasons at Kansas State University Agricultural Research Center near Hays, KS, to understand the emergence dynamics of glyphosate-resistant (GR) kochia [Bassia scoparia (L.) A. J. Scott] as influenced by fall- and spring-planted cover crops (CC) and residual herbicide. Study sites were under winter wheat (Triticum aestivum L.)–sorghum [Sorghum bicolor (L.) Moench]–fallow rotation with a natural seedbank of GR B. scoparia. In Experiment 1, fall-planted CC mixture (triticale/winter peas/radish/canola) was planted after wheat harvest and terminated at triticale [×Triticosecale Wittm. ex A. Camus [Secale × Triticum] heading stage (next spring before sorghum planting). In Experiment 2, spring-planted CC mixture (oats/barley/spring peas) was planted in sorghum stubbles and terminated at oats (Avena sativa L.) heading stage. Four treatments were established in each experiment: (1) nontreated control (no CC and no herbicide), (2) chemical fallow (no CC but glyphosate acetochlor/atrazine or flumioxazin/pyroxasulfone dicamba were used to control weeds), (3) CC terminated with glyphosate, and (4) CC terminated with glyphosate plus residual herbicide (acetochlor/atrazine for fall-planted CC and flumioxazin/pyroxasulfone for spring-planted CC). Results indicated that fall-planted CC delayed GR B. scoparia emergence by 3 to 5 wk, whereas spring-planted CC delayed emergence by 0 to 2 wk compared with nontreated control. Fall-planted CC terminated with glyphosate plus acetochlor/atrazine reduced the cumulative emergence of GR B. scoparia by 90% to 95% compared with nontreated control across both years. Similarly, spring-planted CC terminated with glyphosate plus flumioxazin/pyroxasulfone reduced the cumulative emergence of GR B. scoparia by 83% to 90% compared with nontreated control. These results suggest that fall- or spring-planted CC in combination with residual herbicide at termination can be utilized for GR B. scoparia suppression. Results from this study will help in developing prediction models for GR B. scoparia emergence under different CC strategies.

Sachin Dhanda and Vipan Kumar "Effect of Fall- and Spring-Planted Cover Crops and Residual Herbicide on Emergence Dynamics of Glyphosate-Resistant Kochia (Bassia scoparia)," Weed Science 73(1), 1-9, (14 February 2025). https://doi.org/10.1017/wsc.2024.71
Received: 14 August 2024; Accepted: 16 September 2024; Published: 14 February 2025
KEYWORDS
central Great Plains
cover crops
Cumulative emergence
emergence periodicity
weed seedbank
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top