Excerpts from the report Preface: This study of cotton ginning and harvesting practices is part of a broad program of research by the Agricultural Marketing Service to improve product quality and increase efficiency in marketing agricultural products. It is related to a series of investigations on the effects of various cotton ginning and harvesting practices on the grade and staple length, fiber quality, processing performance, and quality of products manufactured from raw cotton. This research, aimed at preserving the inherent quality of cotton along with the use of efficient and economical practices, is conducted by the Market Quality Research Division of the Agricultural Marketing Service in cooperation with the Economic Research Service and the Agricultural Research Service, various State Experiment Stations, and private industry groups. This report deals with the fiber properties and spinning performance of a widely grown variety of Mississippi Delta cotton as affected by certain practices in drying, cleaning, and conditioning seed-cotton and lint at the gin for mechanically-harvested and hand-picked lots. It analyzes effects of these practices on lint quality, as it relates to cotton bale market values and mill processing costs.