Effects of Leaf and Bract Trichomes On Trash Content and Quality of Ginned Lint

Spinning mills desire cotton fiber with low trash content. The origin of lint trash content is primarily other parts of the cotton plant such as leaf, bract, stem, and seed which machine harvesters tend to extract along with seed cotton. Seed cotton and lint cleaners in gins are utilized to remove these materials. Proper defoliation and harvester maintenance before harvesting reduces trash content, but leaves of the cotton plant tend to cling to cotton bolls due to the presence of leaf trichomes. Defoliation has no effect on bracts of cotton bolls. Trichomes of the leaf and bract tend to cling to cotton fiber affecting cleaning efficiency in the gin and trash content of ginned lint. Cotton varieties differ in leaf and bract trichome density, so a two year study was initiated to determine the effects of leaf and bract trichome density on cleaning efficiency, trash content, and quality of ginned lint. Ten varieties were grown at six locations in 2010 and 2011. Leaf and bract data were collected from four locations in 2010 and three locations in 2011, and all locations were machine harvested and ginned with typical gin machinery including drying, seed cotton cleaning, and lint cleaning. Preliminary results from 2010 show that varieties with reduced leaf and bract trichome density produced ginned lint with lower trash content.