Defoliation and desiccation to prepare the crop for mechanical harvest has become an important practice an high yielding cotton that still contains considerable green succulent foliage by the time bolls reach maturity. It becomes a necessary aid not only to machine harvest, but continues to gain even more importance due to increased storage of seed cotton in modules for extended periods. Under these conditions, dry seed cotton is essential to maintain grade and seed quality. There are many variables that affect the results obtained from harvest-aid chemicals. In this discussion, "Harvest-aid Chemicals" is used as a collective term referring to both defoliants and desiccants. Otherwise, the specific word will be used, such as desiccant used to prepare the crop for stripper harvest.