The Effect of Surface and Subsurface Drip Irrigation System on Qualitative and Quantitative Characteristics of Dates of Kabkab Cultivar

Increased production per unit volume of consumed water requires more precise planning in selecting the appropriate irrigation method for the optimal use of available water resources in the agricultural sector. The province of Khuzestan has been ranked third with 13.8 percent of the total date production of the country. Therefore, using pressurized irrigation methods with the goal of optimal utilization of water resources is inevitable. This research was carried out with the aim of investigating the possibility of utilizing subsurface drip irrigation systems in date orchards and determining the most suitable irrigation treatments in terms of yield and water use efficiency for Kabkab cultivar. Mohebbi and Alihoori (2013), in a study conducted with four irrigation treatments including surface irrigation and drip irrigation with 75% and 100% cumulative evaporation of class A evaporation pan in Hormozgan province, showed that despite different amounts of water in treatment irrigations, there was no significant difference in fruit yield, vegetative traits, and shading surface. The highest and lowest water use efficiency was obtained from drip irrigation treatment with 75% water and surface irrigation treatment with water content equal to 100% cumulative evaporation from class A evaporation pan. Therefore, irrigation with drip irrigation method and 75% cumulative evaporation from class A pans were recommended for irrigation of palm groves. The results of Mohebi’s (2005) study on comparing the effects of two equivalent amounts of water, 75% and 100% evaporation of class A pan in two methods of drip irrigation and surface irrigation on the growth and development of the palm cultivar Peeyaram showed that, among different treatments, there were significant differences in vegetative growth indices such as the number of leaflets, the trunk diameter, and the shading surface. However, in terms of leaf number, yield and quality characteristics of fruit including pH, moisture, soluble solids and total sugar content, the differences among treatments were not significant. The irrigation interval was two days in a drip method and seven days in a surface treatment. The results also showed that although different treatments provided different levels of water for trees, there was no significant difference between treatments in terms of yield and quality traits. The effect of treatments on vegetative traits and yield was not significant. Water consumption in 75% evaporation treatment in drip irrigation method was as much as about 40% of water use in surface irrigation. Therefore, treatment of 75% evaporation from the pan was introduced in the drip irrigation treatment method.