Evaluation of growth, yield, and water use efficiency and evaporation transpiration of some watermelon accessions at drought stress conditions under different irrigation regimes

This experiment was conducted in order to evaluate resistance to drought stress of watermelon accessions, Isfahan, Sharif-Abad, Crimson sweat and Colocynth as index plant. Experiment performed in Randomized Completely Block Design as split plot with four irrigation regimes (100% as control, 75%, 50% and 25% of available water). Results showed that the longest shoot and high number of female flower was at 100% and 75% AW while the lowest level was observed at 25%AW.The highest water use efficiency obtained from Crimson sweat with 34/16 Kg/m3 at 75%AW. The maximum fruit yield (ton/hectare) was for Sharif-Abad in control treatment and minimum amount for crimson sweat at 25%AW without any fruit. Sharif-Abad and crimson sweat had highest contents of total phenolic compound with increasing stress level in comparison with other samples. As a whole, based on results, Sharif-Abad accession was more tolerant accession in stress conditions. In respect to Evaporation Transpiration and KC, crimson sweat allocated maximum and colocynth minimum amount. The use of local and tolerant watermelon in breeding program and irrigation management could help in overcoming water shortage.