Leaf water retention of excised leaves as a measure of drought resistance in grain sorghum (Sorghum bicolor L. Moench) genotypes

The objective of these experiments was to evaluate the usefulness of the excised leaf water retention capability (ELWRC) technique for screening grain sorghum genotypes for drought resistance. Seven genotypes were planted in a randomized block consisting of four replications. The plants were kept under severe moisture stress. In addition to their ELWRC, the canopy temperature, diffusive resistance, transpiration and yield potential was measured. Significant differences between genotypic means were obtained for ELWRC and yield potential only. These were significantly correlated (r = 0,89). Correlations between the other characteristics are discussed. Only additive genetic variation was detected for ELWRC in a partial diallei of three female and nine male inbred lines. It was concluded that ELWRC was a satisfactory screening technique for drought resistance of the sorghum genotypes included in these experiments.