Produtividade e desenvolvimento do sorgo granífero sob diferentes manejos hídricos, adubação nitrogenada e inoculação com Bacillus aryabhattai

Abstract

Grain sorghum exhibits high adaptation to water stress conditions, making it a viable crop for semi-arid regions. The objective of two studies was to evaluate the development and yield of grain sorghum (cv. LAS 3004 G) under different water management strategies associated with nitrogen fertilization and inoculation with Bacillus aryabhattai. Growth and yield variables, such as stem diameter, plant height, panicle mass, and panicle length, were analyzed. The experiments were conducted in a greenhouse at the Federal University of Ceará, Fortaleza, Brazil. Two experiments were carried out in a randomized block design: Experiment I followed a 5x2 factorial scheme (five irrigation depths: 40, 60, 80, 100, and 120% of crop evapotranspiration (ETc); and two nitrogen application methods: conventional and fertigation, totaling 40 experimental units); and Experiment II followed a 5x2 factorial scheme (five irrigation frequencies: 1, 2, 3, 4, and 5 days based on daily ETc; with and without inoculation, totaling 40 experimental units). In Experiment I, results indicated that the 80% ETc irrigation depth was the most efficient, promoting growth similar to higher depths with lower overall water consumption. In general, higher irrigation depths reduced the crop cycle, anticipating flowering and harvest. There was no significant difference between nitrogen application methods for yield variables. In Experiment II, inoculation with B. aryabhattai shortened the crop cycle and mitigated the effects of water deficit, increasing panicle mass by 60.76% under the highest water restriction (5-day irrigation frequency) compared to the non-inoculated treatment. Higher irrigation frequencies (F1 and F2) significantly influenced the development and yield of the sorghum crop. The crop cycle was extended under conditions of lower water supply. Inoculation with Bacillus aryabhattai promoted increases in yield variables, especially under higher water stress conditions, indicating a mitigating effect