Planting date, row configuration and plant population effects on growth and yield of dryland sorghum in subtropical South Texas

Abstract

Grain sorghum is well adapted to semi-arid environments, but production practices must be optimized. A four-year study was conducted to determine the effects of planting date, row configuration and plant population on dryland sorghum growth and yield in subtropical South Texas. The earliest possible planting in order to take advantage of favorable growing conditions without being exposed to adverse environmental conditions was found to produce the best yields. While row configurations which provide the most equidistance spacing for plants produced the highest leaf area index, narrower 76 cm rows planted either single or double row produced the best plant growth and grain yield most years. Studies have suggested that when soil moisture is limited, configurations which limit biomass production would conserve moisture for grain production resulting in improved grain yields. However, in this study configurations that caused the greatest plant dry weight resulted in the best grain yields. Rainfall before or during grainfill may have compensated for any reductions in water availability. Different plant populations within the range of 173–272 × 1000 ha−1 had no effect on sorghum yields, confirming the ability of this crop to compensate for changes in available space.