Seed Development and Determination of Physiological Maturity of Sorghum Seeds (Sorghum bicolor L. Moench) varietas Samurai

Seed development and physiological maturity is an important factor in determining harvest time. The dose of fertilizer will affect the development and viability of the seeds. The purpose of the research is to study the development of sorghum seeds and the effect of fertilizer dosage on seed viability at seed maturity stages. The experiment was arranged using a Split Plot Design with a Completely Randomized Design. The main plot is the dose of NPK fertilizer, and the subplot is the stages of seed maturity. The fertilizer doses used were P1 (67.5 kg N/ha, 36 kg P2O5/ha, and 50 kg K2O/ha), P2 (101.5 kg N/ha, 63 kg P2O5/ha, and 87.5 kg K2O/ha). The seed maturity stages were 25, 30, 35, and 40 days after anthesis (DAA). The treatment was repeated three times. Planting was carried out at the Leuwikopo Dramaga Experimental Field, at an altitude of 183 m above sea level, an average rainfall of 878 mm/month, an average temperature of 26˚C, and an average relative humidity of 82%. Seed moisture content decreased along with seed development, from 46.4% at 25 DAA to 19.9% at 40 DAA. The weight of 1000 grains and seed vigor (speed of germination and seedling growth rate) reached a maximum at 35 DAA and did not differ from the maturity stage of 40 DAA. Sorghum seed achived physiological maturity at 35 DAA. Both fertilizer doses produced the same seed quality.