Location: Soil Dynamics ResearchTitle: Cover crop response to residual herbicides in peanut-cotton rotation
|PRICE, KATLYN - Auburn University|
|LI, STEVE - Auburn University|
Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/26/2018
Publication Date: 7/10/2018
Citation: Price, K., Li, S., Price, A.J. 2018. Cover crop response to residual herbicides in peanut-cotton rotation [abstract]. American Peanut Research and Education Society Abstracts.
Technical Abstract: Cover crops can provide many benefits to peanut and cotton rotation in terms of suppressing weeds, conserving soil moisture for planting, increasing soil organic matter, and reducing soil erosion. However, in fields where residual herbicides were used during the growing season, establishment of cover crops can be negatively affected by the herbicide residues. The objective of this study was to investigate the responses of six cover crops (daikon radish, cereal rye, cocker oats, crimson clover, winter wheat, and common vetch) to twelve common soil herbicides used in peanut and cotton. A multi-year (2016-2018), multi-location study was conducted in Macon and Henry County in Alabama. Herbicide treatments were applied at 10% of full labelled rate at planting. At 50 and 150 days after planting (DAP), plant heights and stand counts were evaluated as well as wet biomass at 150 DAP. Treatments included S-metolachlor, acetochlor, pyroxasulfone, diclosulam, imazapic, chlorimuron ethyl, bentazon plus acifluorfen, pyrithiobac sodium, trifloxysulfuron sodium, diuron, prometryn, flumioxazin, and a non-treated check (NTC). At 145-149 DAP, all affected cover crops had recovered from herbicide damage and did not show any significant treatment differences in any of the growth parameters evaluated in 2016. In 2017, wheat had a significant stand reduction of 24% for flumioxazin at 42-45 DAP over both locations. At 147-149 DAP, clover had a significantly reduced stands of 29-41% for diclosulam and trifloxysulfuron sodium respectively, over both locations. Radish also had a significantly reduce stand of 66% for diclosulam. Oats, rye and vetch did not have any significant stand reductions at either timing in 2017/2018. Oats showed the most tolerance with no treatments significantly reducing stands or plant heights for either year. Overall, the type of cover crop planted should be based on the residual herbicides applied to row crops the previous season as well as the biomass goal and nutrient needs of the field. Although initial injury and stunting may occur, biomass of those cover crops may not be affected by herbicide residues evaluated in this study.