Mwangi PG, Gachuiri CK, Mbugua PN. 2017. Effect of growth stage on fodder yield and quality of dual purpose sorghum. Trop Drylands 1: 100-104. Improved Dual Purpose Sorghum (IDPS) (Sorghum bicolor-Var Ikinyaruka) were yielded at six physiological growth stages to evaluate the impact of growth stage on crop and feed quality. Six treatments based on sorghum growth’s physiological stage were randomly administered to the plot in a block and replicated three times. The treatments were IDPS yielded at bloom stage (PS1), soft dough stage (PS2), hard dough stage (PS3), physiological maturity stage (stalks with grains), (PS4), physiological maturity stage (stalks without grains) (PS5), and 1 month post grain reap (PS6). The parameters monitored were Dry Matter (DM) crop, Crude Protein (CP), Neutral Detergent fiber (NDF), Acid Detergent Fiber (ADF), Acid Detergent Lignin (ADL), In vitro Dry Matter Digestibility (IVDMD) and shoot count. The highest DM crop (18.0 ton/ha) was achieved at PS4 secernated with 8.69, 12.75, 16.27 17.04 and 13.04 ton/ha for PS1, PS2, PS3, PS5 and PS6, respectively. CP reduced with maturity from 8.6 at PS1 to 7.98, 7.96, 7.61, and 6.77 to 6.72 at PS2, PS3, PS4, PS5 and PS6 respectively. NDF and ADF at PS1, PS2, PS3, PS4, PS5 and PS6 were 54.4, 60.8, 65.71, 65.93, 66.73 70.3 and 27.93, 35.96, 41.98, 41.97, 42.04, 46.05 respectively. ADL was 3.44, 5.03, 7.38, 7.39, 7.42, and 8.3 for PS1, PS2, PS3, PS4, PS5 and PS6 respectively. Highest fodder IVDMD of 60.72 was at PS1 secernated with 60.12, 54.73, 53.82, 53.56 and 45.75 achieved at PS2, PS3, PS4, PS5 and PS6 respectively. The PS3 growth stage yielded in fodder material with highest nutritive value while highest fodder yields were achieved at PS4. Reaping at PS5 supplied both fodder and grains for livestock and human consumption respectively. It was proven that crop and quality of IDPS were affected by age at reaping time.