Determination of plant water stress index in sorghum using infrared thermometer technique and programming irrigations

This study was carried out in the Research and Application area of Çukurova University, Faculty of Agriculture, Department of Agricultural Structures and Irrigation in 2018 in a randomized block design with 3 replications. In the experiment, the effects of different irrigation levels on the plant water stress index (CWSI) and some plant growth parameters in the first crop sweet sorghum plant were investigated. In the research, 4 different irrigation water levels were formed during the plant development periods: 100% irrigation (I1), 75% irrigation (I2), 50% irrigation (I3) and 25% irrigation (I4) and no water (I0). At the end of the study; 414.2 mm (I1), 323.5 mm (I2), 232.9 mm (I3) and 142.2 mm (I4) irrigation waters were applied to the trial subjects, respectively. The dry matter yield obtained according to the subjects in the study varied between 6020 kg/da and 3380 kg/da, and the highest dry matter yield was obtained in the fully irrigated subject. In the study, leaf area index values of sorghum plant varied between 8.41 and 6.07 and the highest leaf area index value was obtained from full irrigation. As a result of the research, the CWSI values obtained from the trial subjects were determined as 0.02 for the I1 subject, 0.34 for the I2 subject, 0.46 for the I3 subject, 0.59 for the I4 subject, and 1 for the I0 subject, respectively. When the changes in CWSI values were examined in line with these results, it was determined that the CWSI value (CWSI=0.02) obtained from I1 treatment, where the highest plant yield was obtained, could be used in irrigation programming of sorghum plant in Çukurova conditions.