Adapting date palm offshoots to long-term irrigation using groundwater in sandy soil

The date palm can grow in desert areas using high salinity groundwater by increasing the number of irrigation cycles. A field experiment was carried out on date palm cv. Sayer offshoots grown in sandy saline soil during the 2017 and 2018 growing seasons. The outcomes demonstrated that the application of saline (10 dS m^–1) groundwater every four days increased plant height, number of new leaves, total chlorophyll, and relative water content. In turn, the hydrogen peroxide, malondialdehyde, and electrolyte leakage were reduced. Also, the effect of this treatment improved the growth of the plants, thus reduced the absorption of sodium, chloride, and increased potassium, then decreased the Na/K ratio. Cluster analysis showed two distinct cluster groups. In the first group, the dissimilarity between the treatments is illustrated by the influence of freshwater. While the second group showed the similarity between the treatments of four days and every week in the subgroup. Whereas treatment of two weeks duration shows the most detrimental effect on growth indices and chemical properties of offshoots. The utilization of saline groundwater in the water system of the date palm is the best option among the solutions possible in the current conditions of drought and thermal retention.