Vigor tests to predict the emergence of sorghum seedlings

Abstract

The objective of this research was to ascertain the efficiency of three vigor tests as predictors of rate of seedlings emergence under field conditions, as well as to determine the best time and temperature levels to carry out the accelerated aging test on sorghum (Sorghum bicolor (L.) Moench) seeds. Six grain sorghum and five sweet sorghum cultivars were submitted to germination, TZ vigor (tetrazolium), immersion in NH₄Cl, and accelerated aging tests. In the latter the temperatures of 42°C and 45°C, relative humidity of 100%, and exposure periods of 48, 72, 96 and 120 hours were tested. As check, a test of seedling emergence was carried out in the greenhouse. The results indicated that the accelerated aging test was the most efficient to estimate seedling emergence under field conditions; the temperatures of 45°C and 100% relative humidity during 48 hours was the most efficient set of conditions to use on grain sorghum cultivars seeds, and 45°C during 72 hours to use on sweet sorghum cultivar seeds.