Impact of Varying Nitrogen Doses on Forage Yield and Yield Components in Sweet Sorghum [Sorghum Bicolor Var. Saccharatum (L.)] Genotypes

The study aimed to determine the forage production potentials of different sweet sorghum genotypes under Mediterranean-type climate conditions as a second crop. The field experiments were conducted in Bursa Uludag University, Faculty of Agriculture, in 2020-2021. The experimental design was a factorial randomized complete block with three replications. Three different sweet sorghum genotypes (Erdurmuş, Uzun, and M81-E) and four nitrogen doses (0, 75, 125, 175 kg ha-1) were used in this research. Forage yield, dry matter yield, plant height, stem diameter, leaf number, leaf ratio, and stem ratio of sweet sorghum were investigated in the experiment. Among the three sweet sorghum genotypes studied, a varied range was observed regarding plant height (262 to 288 cm), stem diameter (19.2 to 24.8 mm), leaf ratio (11.5% to 14.4%), stem ratio (85.6 to 88.5 mm), forage yield (28.6 to 56.2 t ha-1) dry matter yield (7.8 to 15.7 t ha-1). According to the research results obtained in the second crop conditions, it can be recommended to grow the M81-E genotype using a nitrogen dose of 175 kg ha-1 in terms of high forage and dry matter yields.