Plant density and nitrogen fertilizer effect on grain yield, yield components and some plant characters of sorghum

Grain sorghum is the fifth most important grain in the world in terms of human and animal nutrition, after rice, barley, wheat and corn. Originating from North Africa, the plant is widely cultivated in tropical and subtropical regions. This study was carried out to investigate the effects of plant density and nitrogen fertilizer on grain yield per unit area and some other agronomic characters and to determine the highest grain yield per unit area in Öğretmenoglu 77 grain sorghum cultivar grown in Samsun-Atakum clayey and Samsun-Bafra sandy soil. This study was carried out in 2021 to determine the most appropriate plant density and nitrogen fertilizer levels. Four nitrogen doses (0, 10, 20, 30 kg/da) and four plant density (30, 60, 90, 120 plants/m2) were applied with three replications in the experiment, which was organized in the split plots experimental design in random blocks. The grain yield per unit area and the data of 14 different plants, cluster and grain characteristics were analyzed by combining the two locations. The effect of nitrogen dose applications on the grain yield in the plot was significant and the maximum grain yield in the plot was obtained from the application of 30 kg nitrogen dose per decare. The effect of plant density on the seed yield in the plot was significant and the maximum seed yield in the plot was obtained from 90 plants per square meter. Plant density affected grain yield per unit area negatively at low nitrogen doses and positively at medium and high nitrogen doses. The interaction of nitrogen × plant density was significant and the maximum grain yield was obtained from the combination of 20 kg nitrogen dose per decare and 90 plant density per square meter.