Germination of Sorghum Under the Influences of Water Restriction and Temperature

The study had the aim to evaluate the germination responses provoked by water restriction and by the effect of temperature on seeds of S. bicolor cultivar BR-700. The experimental design was to carried out in 3×8 factorial scheme, with 3 temperature levels (26, 30 and 34°C), combined with 8 osmotic potential levels that simulate water restriction (Qs = 0.0, -0.1, -0.2, -0.3, -0.4, -0.5, -0.6 and -0.7 MPa). The analyzed variables were the germination percentage (%G) and the mean germination time (MGT). It was showed progressive fall in %G due to the decreased Qs of the environment, independent of the temperature, caused by the low water conductivity and slow water absorption by the seed. MGT reduced occasioned by temperature increased, in the interval between 26-34oC, provoked by an acceleration of biochemical reactions involved in germination. Moreover, the water restriction, as well as the Qs reduced, proportioned a maximization of MGT.