Abstract
This study aimed to determine the effects of biologically active substances and nitrogenphosphorus fertilizers on the yield of sugar sorghum (Sorghum bicolor L.) grown in southern Kazakhstan.A three-year field experiment was conducted using a factorial design with the sorghum variety 'Kazakhstanskoe 20'.Three fertilizer treatments (control, N30P30, N60P60, N90P90 kg/ha) were combined with three seed treatments (Celeste Top, Gumi 20, Potassium Humate).Sorghum was harvested at the wax ripeness stage.Analysis of variance was used to analyze the data.Fertilizer dose, seed treatments, and their interaction significantly increased sorghum green mass yield compared to the control.The highest yields (18.0-19.3t/ha) resulted from combining N90P90 fertilization with seed treatments.Celeste Top and Gumi 20 increased yields by 1.6-4.1 t/ha across fertilizer doses, while Potassium Humate had the greatest effect (increase of 2.7-5.4 t/ha).The integrated use of biologically active seed treatments and moderate to high doses of nitrogen-phosphorus fertilizers can substantially increase the productivity of sugar sorghum grown in southern Kazakhstan.These findings provide agronomic strategies to improve sorghum yields under arid conditions.