Yield, fruit quality and physiological responses of melon cv. Khatooni under deficit irrigation

Abstract

To evaluate the effect of water deficit stress on growth, yield, fruit quality and physiological traits of melon cv. Khatooni, field experiments were conducted in split plot randomized complete block design with three replications. In 2014, irrigation treatments consisted of two deficit irrigation regimes, 33% and 66% of ETc (crop evapotranspiration), and 100% ETc as the control (DI33, DI66 and I100). In 2015, irrigation treatments applied were: 40, 70 and 100% ETc (DI40, DI70 and I100). The results showed that plant height and leaf area decreased from treatment I100 to DI40 and DI33. The highest average fruit weigh and yield were obtained from irrigation 100% ETc for both years. The water use efficiency (WUE) significantly increased in response to increase water deficit stress. Deficit irrigation treatments significantly decreased leaf relative water content, vitamin C and fruit firmness, whereas antioxidant enzymes activity, proline and total soluble solid contents increased. These results suggest that the crop is sensitive to water deficits, that moderate water stress (DI70 and DI66) reduced yield by about 28.5-38.2% and severe water stress (DI40 and DI33) had a much more marked effect, reducing yield by 48.1-61.4%.