Weed Control in Reduced Tillage Cotton Production Systems

C.T. Bryson


 
ABSTRACT

Long-term field experiments were conducted from 1985 through 1991 at Stoneville, Mississippi on a Dundee very fine sandy loam (Aerie ochraqualf) soil to evaluate the effect of four cotton (Gossypium hirsutum L.) tillage production systems on weed control and crop stand, growth, and yield. Cotton tillage production systems included: (a) no-tillage; (b) conventional tillage consisting of fall subsoil, spring chisel plowing, double-disk incorporated of preplant herbicides, bedding, knocking down beds, and three cultivations; (c) reduced-tillage which lacked double disking only (level 1); and (d) reduced-tillage which lacked double disking and chisel plowing (level 2). Two herbicide levels were evaluated for each tillage system. Overall control of grass, broadleaf, and nutsedge was higher at both herbicide input levels for conventional and both reduced-tillage systems when compared to no-tillage treatments in 6 or 7 years. Weed control was greatest in 1991 regardless of tillage or herbicide input level. Cotton growth and yields were not significantly different with conventional tillage and reduced-tillage systems (levels 1 and 2) at both herbicide input levels; however, cotton growth and yields were significantly reduced in no-tillage treatments regardless of the herbicide input level in 6 of 7 years (except 1991). Herbicide inputs alone were ineffective in controlling all weed species in no-tillage treatments, but were more effective in 1991. Over the 7-year period, the most cost effective tillage production systems were as follows: Reduced-tillage, level 2 > reduced tillage, level 1 > conventional tillage > no-tillage. In the no-tillage system, higher costs were due to added herbicide input costs and reductions in cotton yields in 6 of 7 years. Higher input costs with conventional tillage were due to the added tillage operations, but cotton yields were equivalent to those in the reduced-tillage systems within each year. Based on these data, it seems that herbicides were both most expensive and failed to control weeds adequately in the no-tillage system, but reduced-tillage systems for cotton production appear to offer fewer input requirements without appreciable losses in weed control or cotton yields.



Reprinted from 1992 Proceedings Beltwide Cotton Conferences pg. 1318
©National Cotton Council, Memphis TN

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Document last modified Sunday, Dec 6 1998