MATURATION OF POPCORN SEEDS

The objective of this study was to analyze the maturation process of the popcorn seeds DFT 2 (selection cycle 2). At approximately 30 days after full blooming, when about 50% of the plants exhibited receptive silks, the first harvest of the seeds was accomplished. The other harvests were accomplished at 7-day intervals until seeds reached approximately 12% moisture content (wet basis), which occurred upon the 10th harvesting. Just after each harvest, the seeds were manually husked, to determine their moisture content and the weight of the dry matter. Also the development of the black layer was visually evaluated. After the last harvesting, the seeds were evaluated for retention on sieves, germination and vigor (modified cold, accelerated aging and electric conductivity tests). The popcorn seeds reach the maximum dry matter weight (mass maturity) 68 days after flowering, and the physiological maturity of the seeds (maximum germination and vigor) achieves it from 62 to 68 days after blooming. The seeds show humidity in the grade from 17 to 20%, for occasion of the physiological maturity and mass maturity. The black layer is an efficient visual characteristic to identify the physiological maturity of the seeds