Investigation Effect Deficit Irrigation and Shading on Growth and Quality Fruit in High Density Apple Orchard

The lack of water and food supply makes deficit irrigation will be an unavoidable and widespread action in all aspects of agriculture, especially in high density orchard which aims to increase the quantity and quality of the product, it increases the consumption of water and other inputs. Water productivity is an indicator that shows the product produced per irrigation water consumption. Apple is considered as one of the most important garden and agricultural export products of the country. Recently, apple gardeners are increasingly using shade nets to deal with weather hazards, so this study was conducted to investigate the effect of deficit irrigation and shade nets on water productivity and the quantity and quality of apple fruit.The present research was conducted in the high density apple orchard (cv. Golden Delicious) of Astan Quds Razavi sample farm during during 2021, which was set up as a split plot experiment based on a randomized complete block design (the main plot of irrigation treatments: Full Irrigation treatment (FI),Regular Deficit Irrigation treatment(RDI) and Sustained Deficit Irrigation (SDI) and sub plot: presence (S) and absence(N) of shade net) with four replications.According to the results obtained from this research, (RDI) reduced water consumption by 15% ,7% yield and 3% fruit growth. While the water productivity, firmness, maturity index, total sugar, antioxidant and total phenol increased compared to the control treatment and did not change the fruit juice, also the presence(S) of shade net reduced water consumption by 14% and It has increased yield by 9%. Despite reducing irrigation water consumption by 40%, having the highest amount of water productivity and improving some physicochemical characteristics, sustained deficit irrigation (SDI) severely reduced fruit weight, fruit growth and yield.