Evaluation of cover crop cpecies termination timing prior to cotton production in Mississippi

Authors: DENTON, S.D. - University Of Tennessee; DODDS, D.M. - Mississippi State University; KRUTZ, L.J. - Mississippi State University; VARCO, J.J - Mississippi State University; GORE, J. - Mississippi State University; RAPER, T.B. - University Of Tennessee

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/5/2020
Publication Date: 9/10/2020
Citation: Denton, S., Dodds, D., Krutz, L., Varco, J., Gore, J., Raper, T. 2020. Evaluation of cover crop cpecies termination timing prior to cotton production in Mississippi. Journal of Cotton Science. 24:97-103. https://doi.org/www.cotton.org/journal/2020-24/3/upload/JCS24-097.pdf.

Interpretive Summary: Cover crops are defined as any living ground cover grown in between the harvest and planting of a cash crop. . Recently, there has been renewed interest in the implementation of cover crops in agricultural systems. Timing of termination of cover crops is an important factor for optimal benefits. This research was conducted to determine whether the timing of cover crop termination alters cotton growth and development. The effects of different cover crops or combinations of cover crops and termination timing on cotton emergence, plant height, nodes above white flower and yield was evaluated near Starkville, MS in 2017 and 2018. Timing of cover crop termination had a transient effect on cotton emergence. Relative to terminating cover crops in March or April, terminating in February or May decreased cotton emergence at 7 days after planting (DAP) by up to 26%. However, by 14 DAP, cotton stand averaged 74,190 plants/ha and there was no effect of cover crop termination timing on emergence. There were modest interaction effects of cover crop and termination timing on cotton development including plant height, number of nodes, and nodes above white flower. Cotton lint yield did not differ due to cover crop species but increased up to 8% when cover crop termination was delayed from February until May. This research indicates that April and May are the optimal times to terminate a cover crop in a Mississippi cotton production system, provided there is a suitable environment for healthy cotton growth.

Technical Abstract: The termination timing of cover crops varies by farm. This research was conducted to determine whether the timing of cover crop termination alters cotton growth and development. The effects of cover crop (crimson clover, cereal rye, oat, and a blend of cereal rye + crimson clover) and termination timing (targeted dates 01 February, 01 March, 01 April, and 01 May) on cotton emergence, plant height, nodes above white flower and yield was evaluated near Starkville, MS on a Leeper silty clay loam (fine, smectitic, nonacid, thermic Vertic Epiaquepts) in 2017 and 2018 and near Tribbett, MS on a Dundee silty clay loam (Fine-silty, mixed, active, thermic type Typic Endoqualfs) in 2017. Timing of cover crop termination had a transient effect on cotton emergence. Relative to terminating cover crops in March or April, terminating in February or May decreased cotton emergence at 7 days after planting (DAP) by up to 26%. However, by 14 DAP, cotton stand averaged 74,190 plants/ha and there was no effect of cover crop termination timing on emergence. There were modest interaction effects of cover crop and termination timing on cotton development including plant height, number of nodes, and nodes above white flower. Cotton lint yield did not differ due to cover crop species but increased up to 8% when cover crop termination was delayed from February until May. This research indicates that April and May are the optimal times to terminate a cover crop in a Mississippi cotton production system, provided there is a suitable environment for healthy cotton growth.