Submitted to: Agricultural Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 10, 1998
Publication Date: N/A
Interpretive Summary: Pix is a plant growth regulator that is used throughout the Cotton Belt to control excessive plant growth and to enhance early crop maturity in cotton production. Previous work has shown that the best timings and rates for Pix application vary by location, management practice, field situation, and weather. However, previous studies evaluated alternative Pix application strategies based on physiological results alone (e.g. increased lint yields and/or increased earliness)and did not consider the economic returns obtained from each strategy. This study uses both economic returns and physiological results to identify profitable and effective Pix application strategies for dryland cotton production in the Mississippi Delta. A computer model called GOSSYM/COMAX is used to simulate dryland cotton production under different Pix application strategies, weather conditions and soil types. The authors found that Pix application strategies resulting in the largest lint yields and the largest plant height reductions did not always provide the largest economic returns. Thus, economic returns need to be reported with physiological results when prescribing effective Pix application strategies. The authors also found evidence that economic gains from Pix use tend to be greater on heavy textured soils with low yield productivity than on light textured soils with high yield productivity. The most profitable Pix application strategies were found to vary by soil type and weather condition. Thus, no single Pix application strategy could be recommended for all situations.
Technical Abstract: The plant growth regulator Pix (mepiquat chloride) is used extensively throughout the Cotton Belt to control excessive plant growth and to enhance early crop maturity in cotton production. Economic returns from Pix use can vary greatly across different production environments. This study evaluates the economic returns to dryland cotton obtained from twelve different Pix application strategies under two different soil types (Bosket sandy loam and Dundee silty clay loam) and three different weather conditions (normal, cold-wet, and hot-dry) in the Mississippi Delta using simulated output from the GOSSYM/COMAX cotton management system. The results indicate that economic gains from Pix use are generally greater on fine textured soils with low yield productivity than on coarse textured soils with high yield productivity. The results also demonstrate that Pix application strategies with the largest lint yields do not always result in the largest economic returns.