Effect of seaweed and boron-molybdenum applications on leaf nutrients in pistachio under drought stress

This study aims to determine the effects of seaweed and boron-molybdenum applications on the leaf plant nutrient content of pistachio trees under drought stress. The research was conducted in a farmer's orchard in the Nizip district of Gaziantep province during 2023 and 2024. The experimental material consisted of 25-year-old 'Siirt' pistachio variety grafted on buttum (Pistacia khinjuk) rootstock, planted at 7x7 meter intervals. To determine the effects of the treatments under drought, the experiment was carried out on a total of 30 trees (10 trees per group), consisting of an irrigated treatment group, a non-irrigated (drought) treatment group, and a control group that received neither irrigation nor any fertilizer/seaweed applications. Commercial forms of seaweed and boron-molybdenum fertilizers were used for the applications. According to the statistical analysis of leaf samples taken in August and September, irrigation, year, and sampling period interactions had a significant effect (p<0.05) on potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn) contents. The results indicate that irrigated conditions enhanced plant nutrient uptake, while the negative impacts induced by drought stress were mitigated by the fertilizer and seaweed applications. In conclusion, the findings demonstrate that seaweed and mineral-supported fertilization strategies improve the nutritional status of pistachios under drought stress and contribute to sustainable agricultural practices.