Sensing of moisture stress effects by infra-red thermometry in sorghum, maize and pearl millet

Abstract

Field experiment was carried out on sandy loam soil with sorghum (cv. S-136), maize (cv. Ageti-76) and pearl millet (cv. PHB-14) during the summer season (may–July) of 1980 at Haryana Agricultural University Farm, Hisar. After one uniform irrigation at crop establishment, the crops were subjected to four irrigation treatments, viz. irrigation at ID/CPE (ID=irrigation depth of 7cm; CPE=cumulative pan evaporation) of 1.0, 0.6, 0.3 & 0.15. Changes in soil water potential (ψ soil), leaf water potential (ψ L), stomatal conductance (KL), canopy temperature (Tc), transpirational cooling (Canopy temperature minus air temperature, Tc-Ta), evapotranspiration (ET) and dry matter yields were recorded in different treatments. An increase in moisture stress resulted in a decrease in ψ soil, ψ L, KL, transpirational cooling, ET but increase in Tc. Tc-Ta showed significant curvilinear association with ψ soil and linear relationship with ψ L, KL, Tc, ET and dry matter yield of summer cereals. It is suggested that the mid day values of Tc-Ta as observed with an infra-red thermometer could effectively be used to sense the moisture stress effects in summer cereals.