Efficiency of drip irrigation method in tomato fields under salinity conditions of water resources

In recent decades, the use of saline water in agricultural production has increased dramatically due to the reduction of fresh water resources. But, safe use of saline water requires proper irrigation management. This experiment was carried out to study the effects of water salinity on yield, water use efficiency and fruit quality of drip irrigated tomatoes in southern Iran (Bushehr) with arid and semi-arid weather during one cropping season (2010-2011). The experiment was designed as split plot in a randomized complete block design (RCBD) with four levels of water salinity (1.1, 3.7, 5.5 and 7.5 dS.m-1) and three levels of irrigation intervals (2, 4 and 7 days) with three replications. According to the results, with increasing irrigation interval from 2 to 7 days, the mean values of crop yield (Y), irrigation water use efficiency (IWUE) and fruit weight (FW) decreased by 20, 19 and 26% respectively. Also, with increasing salinity of irrigation water from 1.1 dS.m-1 to 7.5 dS.m-1, these values decreased by 33, 39 and 32% respectively. In general, under climatic conditions and soil characteristics of the experiment site, yield loss due to water salinity was far lower than that reported in FAO No. 29 paper (Ayers and Westcott, 1985). Also, with increasing irrigation interval and salinity of water, fruit quality increased in terms of the amount of soluble solids (TSS).