Effects of Irrigation with Saline Water under Proper Management on Vegetative Growth in Date Palm Seedlings

Salinity of irrigation water is a major limiting factor for the development of irrigated agriculture in arid and semi-arid regions. Moreover, application of saline water might increase soil salinity and mitigate its fertility in the absence of scientific principles and proper management. The present experiment was carried out using a complete block design with five irrigation treatments at the Date Palm and Tropical Fruits Research Center during the period 2017‒2018. The treatments included one irrigation with water abstracted from the Karun River; one with saline water of 5 dS/m; one with saline water of 8 dS/m; two with the Karun River water and one with saline water of 5 dS/m; and finally two with the Karun River water and one with saline water of 8 dS/m, all conducted in triplicates. The results showed that salinity of irrigation water led to significantly reduced leaf number, leaf length, leaf width, leaflet number, leaflet length, and trunk perimeter at the 5% probability level. Maximun and minimun values of plant vegetative properties were obtained under irrigation with water from the Karun River and that with saline water of 8 dS/m, respectively, such that the mean number of leaves and leaflets decreased by 73.0 and 69.2%, respectively. Compared to the irrigation treatment with the water from the Karun River, the one with two irrigations with the Karun River water and once with saline water of 5 dS/m did not lead to any significant reductions in such vegetative characteristics as numbers of leaves and leaflets of the date palm seedlings at the 5% probablity level. It may be concluded that date palm seedlings may be safely irrigated with saline water of up to 5 dS/m if irrigation management is properly implemneted.