Effect of various biomass of cereal rye residue and soil-applied herbicide on the germination of troublesome southeastern weeds

Authors: KUMARI, ANNU - Auburn University; Price, Andrew; GAMBLE, AUDREY - Auburn University; LI, STEVE - Auburn University; JACOBSON, ALANA - Auburn University

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/21/2023
Publication Date: 1/22/2024
Citation: Kumari, A., Price, A.J., Gamble, A., Li, S., Jacobson, A. 2024. Effect of various biomass of cereal rye residue and soil-applied herbicide on the germination of troublesome southeastern weeds [ABSTRACT]. Weed Science Society of America, San Antonio, TX Jan 22-25.

Interpretive Summary:

Technical Abstract: Weed control strategies should be focused on susceptible stages like seed germination. Cover crops are increasingly adopted to suppress weed growth, reducing reliance on chemical herbicides. A greenhouse experiment was conducted to evaluate the germination and growth response of several key Southeast weeds to various cereal rye residue levels. Seeds of Palmer amaranth, sicklepod, morning glory, and crabgrass were mixed with organic garden soil and placed over the top of the tray. The soil flats were covered uniformly by four different biomass of rye straw. The field experiment was conducted at two locations in Alabama in a split-plot design, with the main plot factor being the different seeding rates of cover crops to obtain various cover biomass. In the split-plot factor, the preemergence herbicide Valor was applied. Data collection included weed counting, visual control rating, recording of dry weight, and cover crop biomass. The results illustrated that Palmer amaranth, sicklepod, and crabgrass showed significant germination patterns and dry weight differences under various biomass of cereal rye in the greenhouse study. Meanwhile, the weed count and dry weight of morning glory were insignificant. In both greenhouse and field conditions, morning glory was least responsive to increasing cover crop biomass residue, and Palmer amaranth was the most responsive due to small seed sizes. Cover crop biomass and weed counts were strongly negatively correlated with Pearson correlation coefficients of (0.83) in the case of Palmer amaranth, while weakly negatively correlated in the case of morning glory, with a Pearson correlation coefficient of 0.49. Furthermore, Valor herbicide exhibited 95% control of Palmer amaranth, whereas the non-treated check was 38%, compared to the control (winter fallow without herbicide). For morning glory, Valor resulted in 92% weed control, while the non-treated control exhibited 30%, compared to the control.