Response of sorghum to moisture stress using line source sprinkler irrigation I. Plant-water relations

The response of sorghum (Sorghum bicolor L.) to moisture stress during the post-rainy season was studied at ICRISAT research center on a medium deep Alfisol using a line source sprinkler irrigation system. Changes in soil moisture content, stomatal conductance, leaf-water potential and leaf temperature of sorghum as a function of distance away from the line source sprinkler system were monitored throughout the season. Use of the line source technique facilitated the imposition of a range of moisture stress levels as indicated by increased water use by sorghum closer to the line source compared with the crop farther away from the line source. Canopy response measured in terms of stomatal conductance, leaf-water potential, and leaf temperature clearly reflected the gradient in moisture stress perpendicular to the line source.