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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Publications at this Location » Publication #362625
Research Project: Understanding and Responding to Multiple-Herbicide Resistance in Weeds

Location: Global Change and Photosynthesis Research

Title: Cover crops are not affected by tobacco soil residual herbicides but also do not provide consistent weed management benefits

Author
item HARAMOTO, ERIN - UNIVERSITY OF KENTUCKY
item LOWRY, CAROLYN
item PEARCE, BOB - UNIVERSITY OF KENTUCKY

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2019
Publication Date: 11/22/2019
Citation: Haramoto, E., Lowry, C.J., Pearce, B. 2019. Cover crops are not affected by tobacco soil residual herbicides but also do not provide consistent weed management benefits. Weed Technology. 34:383–393. https://doi.org/10.1017/wet.2019.123.
DOI: https://doi.org/10.1017/wet.2019.123

Interpretive Summary: This work shows that herbicides commonly used in Kentucky tobacco production have no effect on the establishment and growth of cereal rye, wheat, and crimson clover cover crops. The impact of this work is that we provide evidence that tobacco growers can incorporate cover crops into their crop rotations, thus improving weed management and soil health within tobacco production.

Technical Abstract: Cover crops (CC) provide benefits to Kentucky’s reduced-tillage tobacco producers, but soil residual herbicides may interfere with their establishment and growth. We examined residual herbicide effects on CCs, as well as the potential for CC-based weed suppression, within strip tilled tobacco production. We evaluated two winter CC mixtures: wheat (Triticum aestivum L.) plus crimson clover (Trifolium incarnatum L.) and cereal rye (Secale cereale L.) plus crimson clover, along with a no cover crop control. Herbicides included two rates of PRE sulfentrazone (177 or 354 g ai ha-1) plus carfentrazone-ethyl (20 or 40 g ai ha-1); the higher rate was also combined with POST clomazone (840 g ai ha-1) or PRE pendimethalin (1400 g ai ha-1). Two herbicide-free controls (weedy and weed-free) were included. The experiment was conducted from summer 2016 to fall 2018, and the same CC and weed management treatments were applied to each plot for two consecutive years to examine cumulative effects. CC density and biomass were not affected by herbicides. CCs did not affect weed density during tobacco growth, but cereal rye plus crimson clover reduced weed biomass in one year. Overall, weed density and biomass were lower when the higher rate of sulfentrazone plus carfentrazone-ethyl was combined with another herbicide. Weed community composition differed if herbicides were used, but not between CCs. Tobacco yield was unaffected by CCs in 2017, but in 2018 CCs reduced yield in some weed management treatments. In this study, tobacco herbicides did not interfere with wheat, cereal rye, or crimson clover establishment but additional research should determine if these results apply to other environments and soil types. CCs did not interfere with herbicide efficacy, but also did not consistently contribute to weed control; our results also suggest that CCs may reduce strip-till tobacco yield.