Skip to main content
ARS Home » Midwest Area » Columbia, Missouri » Cropping Systems and Water Quality Research » Research » Publications at this Location » Publication #191141
Title: DETERMINING THE OPTIMUM TIMING FOR THE FINAL IRRIGATION ON MID-SOUTH COTTON

Author
item Vories, Earl
item TEAGUE, TINA - UNIVERSITY OF ARKANSAS
item GREENE, JEREMY - UNIVERSITY OF ARKANSAS
item STEWART, JASON - ARKANSAS STATE UNIV
item CLAWSON, ERNIE - LOUISANA STATE UNIV
item PRINGLE, LYLE - MISSISSIPPI STATE UNIV
item PHIPPS, BOBBY - UNIVERSITY OF MISSOURI

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/2/2006
Publication Date: 6/1/2006
Citation: Vories, E.D., Teague, T., Greene, J., Stewart, J., Clawson, E., Pringle, L., Phipps, B. 2006. Determining the optimum timing for the final irrigation on mid-south cotton. In. Proceedings National Cotton Council Beltwide Cotton Conference, January 3-6, 2006, San Antonio, Texas. 516-521, 2006 CDROM.

Interpretive Summary: US Cotton growers are adopting COTMAN, a COTton MANagement system used to monitor crop development and aid in making end-of-season decisions. Currently, research-based decision guides have been developed to aid in determining safe dates for termination of insect control and the application of defoliants. Another area that may benefit from COTMAN information is the decision when to stop irrigating the crop, so data from six years of cotton irrigation studies were analyzed to develop a recommendation for irrigation termination in COTMAN. This research can eliminate end-of-season irrigations that don't result in extra yield, lowering production costs and saving water.

Technical Abstract: US Cotton growers are adopting COTMAN, a COTton MANagement system used to monitor crop development and aid in making end-of-season decisions. Currently, research-based decision guides have been developed to aid in identifying the last effective boll population and determining the optimal dates for safe termination of insect control and application of defoliants based on the occurrence of a first-position white flower five nodes below the terminal (NAWF=5). Another area of cotton production that may benefit from COTMAN is the decision of when to stop irrigating the crop. The objective of this research was to investigate a crop-based recommendation for timing the final irrigation on cotton. Data sets from 26 Mid-South cotton irrigation termination studies during the 2000 through 2005 growing seasons, a total of 432 data points, were fit to a quadratic equation. However, the residual yield values were correlated due to the fact that different studies had quite different yields. To avoid the serial correlation, data from each study were normalized such that the average lint yield for the study was adjusted to 1,000 lb/acre and again fit to a quadratic equation. The resulting equation had a maximum yield of 1021 lb lint/acre at 692 DD60 after NAWF=5. At NAWF=5, generally associated with physiological cutout, the yield was 963 lb lint/acre, 58 lb lint/acre below the maximum. Additional work will be necessary before a recommendation for irrigation termination can be added to COTMAN, including investigating: functions other than the quadratic; the possibility of differences in the northern and southern portions of the Mid-South; and any possible effects on fiber quality, particularly micronaire.