ROLE OF BIO-AZOTOBACTER AND NITROGEN FERTILIZERS ON GROWTH AND YIELD TRAITS OF SORGHUM (SORGHUM BICOLOR L.)

A field experiment on sorghum (Sorghum bicolor L.) with diverse levels of fertilization, carried out in the spring of 2022 in a randomized complete block design (RCBD) with factorial arrangement, had three replications and two factors at the field of Ibn-Al-Bitar Vocational Preparatory School, District AlHussainiya, Kerbala, Iraq. The first factor comprised three sorghum cultivars (V1 = Al-Khair, V2 = Rabeh, and V3 = Bohuth-70), while the second was combinations of nitrogen and bio-fertilizers (F0 = recommended dose of N 320 kg ha-1 , F1 = 3/4 of the recommended amount of N with Azotobacter, F2 = 1/2 of the recommended dosage of N + Aotobacter, F3 = 1/4 of the recommended dose of N + Azotobacter, and F4 = Azotobacter + No nitrogen fertilizer). The results showed that the sorghum cultivar Bohuth-70 was significantly superior for enhanced plant height (204.63 cm), number of leaves plant-1 (9.807), 1000-grain weight (35.27 g), and the grain yield (6.192 Mg.ha-1 ). However, cultivar Al-Khair produced the highest mean leaf area (4,929 cm2 ) and grains per head (4,428 grains.head-1 ). Cultivar Rabeh excelled in performance, with the highest mean value for stem diameter (24.67 mm) and head length (31.29 cm). The F0 treatment recommended dose of N 320 kg ha-1 was considerably superior in the number of leaves (9.867 leaves plant-1 ), stem diameter (24.8 mm), and grain yield (6.145 Mg.ha-1 ). The F1 treatment of 3/4 of the recommended dose of N with Aotobacter excelled in plant height (166.57 cm), leaf area (4,936 cm2 ), and number of grains (3,916 grain head-1 ). However, the F2 treatment 1/2 of the recommended dose of N + Aotobacter was notably superior in head length (30.18 cm) and 1000-grain weight (29.93 grains). As for the interaction, the sorghum cultivar Bohuth70 with F0 treatment excelled in the number of leaves plant-1 (10.33 leaves) and the grain yield (7.157 Mg.ha-1 ), while the cultivar Al-Khair with F1 treatment excelled in stem diameter (26.70 mm) and leaf area (5,164 cm2 ). A field experiment on sorghum (Sorghum bicolor L.) with diverse levels of fertilization, carried out in the spring of 2022 in a randomized complete block design (RCBD) with factorial arrangement, had three replications and two factors at the field of Ibn-Al-Bitar Vocational Preparatory School, District AlHussainiya, Kerbala, Iraq. The first factor comprised three sorghum cultivars (V1 = Al-Khair, V2 = Rabeh, and V3 = Bohuth-70), while the second was combinations of nitrogen and bio-fertilizers (F0 = recommended dose of N 320 kg ha-1 , F1 = 3/4 of the recommended amount of N with Azotobacter, F2 = 1/2 of the recommended dosage of N + Aotobacter, F3 = 1/4 of the recommended dose of N + Azotobacter, and F4 = Azotobacter + No nitrogen fertilizer). The results showed that the sorghum cultivar Bohuth-70 was significantly superior for enhanced plant height (204.63 cm), number of leaves plant-1 (9.807), 1000-grain weight (35.27 g), and the grain yield (6.192 Mg.ha-1 ). However, cultivar Al-Khair produced the highest mean leaf area (4,929 cm2 ) and grains per head (4,428 grains.head-1 ). Cultivar Rabeh excelled in performance, with the highest mean value for stem diameter (24.67 mm) and head length (31.29 cm). The F0 treatment recommended dose of N 320 kg ha-1 was considerably superior in the number of leaves (9.867 leaves plant-1 ), stem diameter (24.8 mm), and grain yield (6.145 Mg.ha-1 ). The F1 treatment of 3/4 of the recommended dose of N with Aotobacter excelled in plant height (166.57 cm), leaf area (4,936 cm2 ), and number of grains (3,916 grain head-1 ). However, the F2 treatment 1/2 of the recommended dose of N + Aotobacter was notably superior in head length (30.18 cm) and 1000-grain weight (29.93 grains). As for the interaction, the sorghum cultivar Bohuth70 with F0 treatment excelled in the number of leaves plant-1 (10.33 leaves) and the grain yield (7.157 Mg.ha-1 ), while the cultivar Al-Khair with F1 treatment excelled in stem diameter (26.70 mm) and leaf area (5,164 cm2 ).