Three picker harvested modules and one stripper harvested module were built in 1981 and again in 1982 and stored for eight weeks. Samples from each module were ginned weekly to determine the quality of the lint and seed. Preharvest conditioning of the plants was varied to provide seed cotton with varying amounts of trash and trash moisture, and to determine their effect during storage on lint and seed quality. The stripper module built in 1981 heated up to 140 degrees F and was ginned after three days storage. These high temperatures resulted in some light spotted grades. Results from the picker harvested modules indicated a reduction in lint and seed grades after eight weeks of storage. The high percentage of moisture in the green plant material stored with the seed cotton could be a source for heat buildup in the module.