Seventy-nine strains of stripper harvested cotton were evaluated in a ginning study to determine the effects of selected genetic characters on seed cotton cleaning efficiency, ginning rate, lint cleaner performance, and dust content of ginned lint. Twenty-one plant, fiber,and seed characters were examined by regression analysis to identify those factors associated with finning performance and lint cleanliness.

The performance of the gin's seed cotton cleaning system was related to a number of genetic factors. Positive correlations were found between cleaning efficiency and micronaire, peduncle length and strength, and plant height. Fiber length and strength, lock tenacity, leaf hairs, seed-to-lint ratio , and plant maturity rating were associated negatively with seed cotton cleaning efficiency. These ten factors accounted for 40 to 60 percent of the variation in bur-, stick-, and fine trash-removal efficiency.

Lint cleaner efficiency was not closely associated with any of the genetic factors evaluated in this study; however, foreign matter content of ginned lint was related to several plant and fiber characters. Positive correlations were obtained for plant maturity rating, leaf hairs, boll angle, seed-to-lint ratio, and fiber length. Micronaire, plant height, and lock tenacity were negatively correlated with lint foreign matter. These eight factors explained about 65 to 75 percent of the variation in lint foreign matter before and after lint cleaning. With the exception of fiber length, these same factors were also associated with dust content of lint. In addition, positive correlations were found between dust content and bract teeth and seed count. Nine genetic factors explained about 70 percent of the variation if dust content.

Ginning rate was closely related to those factors which characterize the seed and the relative proportions of seed and lint. See-to-lint ratio, linters and lint index were negatively correlated with ginning rate. Positive correlations were found between ginning rate and fiber color. These factors along with moisture content explained about 50 percent of the variation in ginning rate.