Sorghum Cultivars Adapted to Rising AIr Temperature

The impact of climate on sorghum cultivation, generated mainly by scenarios of increased temperature, can affect plant development and cause losses in crop yield. Thus, the objective of this work was to select sorghum cultivars tolerant to high temperatures, through the evaluation of biometric, enzymatic, and productive parameters. The experiment was carried out in growth chambers, with seven sorghum cultivars (AGRI-002E, BRS 506, BRS 716, SF 15, IAC Santa Elisa, BRS Ponta Negra, and Volumax) and four temperature regimes (20.0-26, 0-33.0°C; 24.8-30.8-37.8°C; 26.3-32.3-39.3°C and 27.8-33.8-40.8°C), in a completely randomized design, with four replications. The biometric and productive parameters and activity of the enzymes superoxide dismutase, catalase, and ascorbate peroxidase were evaluated. The cultivars AGRI-002E, BRS 506, BRS Ponta Negra, and Volumax showed better defense of the antioxidant system with increasing air temperature, with less accumulation of reactive oxygen species and greater biomass production. These cultivars can be classified as tolerant to an increase of up to 6.3 °C in air temperature, with emphasis on cultivar BRS 506, which showed higher production of stem dry mass.