The quality of hybrid cotton seed on the Texas High Plains as influenced by degree days accumulated resulting from pollination

In the production of hybrid cotton seed, honey bees are utilized from the onset of bloom to approximately 20 August, on the Texas High Plains. In an "average" year, blooms set after this date will not develop into a mature boll due to the length of maturity. Climatic conditions during the postmaturation preharvest period have a great influence on the quality of seed harvested.

Degree days were accumulated from the onset of bloom to 20 August, and divided into four equal periods to determine the quantity and quality of hybrid cotton seed produced during these time periods. The results indicate that 40-80% of the seeds are produced during the first two degree day periods, depending on both the number of degree days accumulated preharvest and the amount of pollen transfer. Seeds produced during this time period have a higher germination rate and a higher seed weight than seeds produced during the second half of the bloom period.