Abstract: There are problems in direct-seeding sorghum in Southwest China, including variable sowing date, unstable seedling situation, low yield, and low efficiency. A new sorghum variety ‘Chuannuoliang No. 1’ was used as the test material to study the variations of growth process, dry matter accumulation, yield and its composition of sorghum under different sowing dates through field trials from 2015 to 2016. The results showed that, with the delay of sowing date, the growth period of sorghum gradually shortened, while dry matter accumulation, yield and its composition (number of kernels per ear, 1000-kernel weight, and kernel weight per ear) of sorghum increased first and then decreased. The dry matter accumulation, yield and its composition under sowing date D3 (April 20) were higher than that under other sowing dates. The growth duration was significantly negatively correlated with average daily temperature, while the dry matter accumulation and yield were significantly positively correlated with the accumulated temperature. Temperature was the key meteorological factor driving the yield differences of sorghumamongsowing dates. Temperature affected the growth process and dry matter accumulation, then regulated the kernel number per ear and kernel weight per ear, and ultimately affected grain yield of sorghum. April 20 is the suitable sowing date for ‘Chuannuoliang No. 1’ in Southwest China.

Key words: sorghum, sowing date, direct seeding, dry matter, yield.