Physiological basis for increasing and stablising yield under drought in sorghum

Although drought causes more yield losses than combined effect of all biotic stress factors, the progress in increasing yield under water-limited conditions is small. Major reasons for slow progress are listed and the relationships between crop productivity and drought resistance are examined. Adapations to drought in sorghum are discussed in order of their utility in the immediate future: phenological, morphological, physiological and biochemical. Results of interdisciplinary research in understanding drought resistance are discussed with respect to available screening methods, genetic variability and breeding methods. Breeding and managment strategies should be aimed at increasing transpirational water use throughout the season and decreasing injury caused by drought.