Effect of different irrigation levels on yield and water use efficiency of greenhouse cucumber

Because of the water crisis in the country, the use of greenhouse cultivation for optimal use of water resources is expanding. The main purpose of this research project was to determine the appropriate amount of irrigation water for growing cucumber (Negin cultivar) greenhouse. For this purpose, an experiment was performed in a randomized complete block design with three replications. Irrigation treatment included treatment of 100% of water requirement based on reaching the suction of tensiometer to 40 bars. The other two water treatments were 20% less and more than the 100% of water requirement. The results showed that the effect of irrigation treatments on yield, number of fruits per plant, number of deformed fruits, the average weight of a cucumber, and water use efficiency were not significantly different, although yield, the number of fruits per plant and the average weight of a cucumber increased. The volume of irrigation water increased, and the number of deformed fruits and water use efficiency decreased. The combined analysis showed that yield, water use efficiency, and the number of fruits per plant in summer cultivation were significantly higher than winter cultivation. So that the highest yield and water use efficiency were obtained in the treatment of 120 and 80% in the summer of 21.14 kg / m2 and 0.49 kg / m3, respectively. The average weight of fruit was higher in winter cultivation. Although the number of deformed fruits in both crops was not statistically different, the percentage of deformed fruits to the total number of fruits in winter and summer cultivation was 33.2% and 17.6%, respectively. The volume of water used in the treatment of 80, 100, and 120% of water requirement in winter cultivation was 0.271, 0.335, and 0.408, respectively, and in summer cultivation was 0.360, 0.439, and 0.524 m3 / m2. Based on the results of experiments in winter and summer cultivation, the effect of irrigation level on greenhouse cucumber yield was not significant. Therefore, instead of full irrigation, 80% of the water requirement can be used.