Effects of Sowing Time and Growing Density on Agronomic Traits, Grain Yield, and Grain Quality of Waxy Sorghum Cultivar Hongliangfeng 1

The aim of this study was to determine the effects of sowing time and growing density on the yield and quality of grain in waxy sorghum (Sorghum bicolor L. Moench). The main plots were two sowing time: early sowing (5 April) and late sowing (20 April), and the subplots were three growing densities: 0.8 × 105, 1.1 × 105, and 1.4 × 105 plants/ha. Results showed that sowing time and growing density had significant effects on grain yield and grain quality of waxy sorghum cultivar Hongliangfeng 1. Grain yield, plant height, spike length, culm diameter, grain number per spike, grain weight per plant, 1000-grain weight, protein content, starch content, and amylopectin content were reduced by a delay of sowing time, while the tannin content and amylose content were increased by a delay of sowing time. Grain yield, plant height, spike length, culm diameter, grain number per spike, grain weight per plant, 1000-grain weight, protein content, starch content, and amylopectin content increased and then decreased with the increase of growing density, while the tannin content and amylose content decreased and then increased with the increase of growing density. These results hinted that appropriate sowing time and growing density are key cultivation measures to ensure high yield and good quality in waxy sorghum production.