EVALUATION OF FIVE SORGHUM GENOTYPES (Sorghum bicolor (L.) Moench) UNDER WATER STRESS IN NORTH KORDOFON STATE

Abstract

The study was conducted during two successive seasons (2014/015–2015/016) with four experiments (two field experiments which were carried out at the Crop Sciences Experimental Farm, Faculty of Natural Resources and Environmental Studies, University of Kordofan and two other laboratory experiments which were carried out at the Regional Seed Center Laboratory, Agricultural Research Corporation (ARC), Elobied. The aim of these experiments was to evaluate five sorghum genotypes under water stress and to examine the effect of water limitation on seed quality during seed filling period. In the field experiments, two factors were studied, namely; genotypes and water regime. The five sorghum genotypes were: Taggat 9, Taggat 10, Taggat 14, Taggat 19 and Gadambalea and the three water regimes were: well watering every seven days as control (IR0), withholding irrigation at three-leaf stage for 21 days as stress one (IR1) and withholding irrigation at eight-leaf stage for 21 days as stress two (IR2). The field experiment was laid out in a Randomized Complete Block Design (RCBD) with four replications within split-plot experimental arrangement. The main plots were specified to water stressed treatments, while genotypes were placed as subplots. The laboratory treatments were conducted as factorial experiments in a Randomized Complete Block Design with four replications. The parameters that measured from the field experiment were plant height, number of leaves/plant, days to 50% flowering, days to 95% physiological maturity, number of heads/plot, number of grains/panicle, panicle length and weight, 100-grain weight, grain yield/plant, grain yield/m2, grain yield (ton/ha), harvest, drought tolerance and seed indices, soil moisture content and consumed moisture in the soil. At laboratory experiment, parameters were: germination%, seedling vigor traits. Statistical analysis revealed significant effects of each of water regimes, genotypes, and their interactions for most of the studied traits in both seasons. In this respect, withholding irrigation at eight-leaf stage consistently resulted in reducing growth, IV yield, and yield components and seed quality compared with well-watering and withholding irrigation at three-leaf stage. Results also showed that stressed plants at three-leaf stage exhibited the highest estimates in plant height (between 141 and 144 cm), number of grains per head (between 1385 and 1577) and seedling relative moisture content (between 1.95 and 1.97). The results revealed that Taggat10 and Taggat 14 were the late matured genotypes and showed the best perform once for yield (4.2 and 4.5 ton/ha, respectively) and in seed vigor, whereas, the early matured genotypes (Gadambalea and Taggat 9) performed best in drought tolerance index (0.8 and 0.9, respectively).