On-Farm Evaluation of Mepiquat Formulations in Southeastern Arizona

Abstract

A single field trial was conducted during the 2004 season to evaluate three different mepiquat formulations used to control vegetative plant growth. This project involved the evaluation of mepiquat formulations of Mepex Ginout (DuPont), Pix Ultra and Pentia (BASF). These three treatments, along with a control, were arranged in a randomized complete block design with four replications. Plots were 20, 36” wide rows and extended for a full one half mile irrigation run. Applications of all treatments were made on 22 July 2004 at a rate of 16 oz/acre for each formulation. Lint yields were determined at the end of the season by harvesting the center eight rows of each plot. The harvested seed cotton was weighed using a weigh wagon equipped with load cells. Sub samples were collected from each plot for fiber quality and lint percent determinations. No significant differences were observed among treatments with respect to any of the fiber quality parameters measured. The Mepex Ginout treatment produced the highest lint yield and also the highest percent lint. The control was not significantly different from the other two formulation treatments. Lint percent values had a major impact on lint yield. The control had the lowest seed cotton yield but because of the higher percent lint values, lint yield for the control was ultimately higher than both the Pentia and Pix Ultra treatments. This study demonstrates the positive effect of the PGR applications and also the effect that percent lint can have on final lint yield.