Optimizing pistachio yield and efficiency: Evaluating artificial mulch and shade nets for enhanced drought and salinity resilience

This study investigates the impact of synthetic ground cover (mulch) and shade netting on pistachio trees (Pistacia vera L. cv. ‘Ahmad-Aghai’) under drought and salinity stress during critical reproductive stages. Conducted over four years (2020–2023) in a semi-arid region, the experiment evaluated treatments on nutrient status, physiological traits, growth, thermal regulation, water use efficiency, and yield. The treatments included synthetic mulch, shade netting, their combination, and a control. Results showed that the combined treatment of mulch and shade netting significantly improved leaf nutrient concentrations (e.g., nitrogen 113.4 %, phosphorus 57.1 %, potassium 111.7 %) compared to the control. It also enhanced leaf area, relative water content, and photosynthetic water use efficiency by 17.1 %, 28.3 %, and 91.7 %, respectively, while reducing sodium (Na) concentrations and improving K/Na and Ca/Na ratios. This treatment increased nut yield (101.9 %) and reduced fruit abscission (37.6 %) and blank nuts (58.7 %). Canopy and soil temperatures decreased by up to 21.4 % and 30.9 %, respectively. Additionally, it reduced alternate bearing intensity (27.6 %) and other fruit complications, including endocarp lesions (53.4 %) and deformed nuts (69.1 %). Water application decreased by 39.4 %. Principal Component Analysis (PCA) indicated that the combination of mulch and shade netting improved water use efficiency and tree health. Economic analysis confirmed the cost-effectiveness of the combined treatment, yielding significant returns on investment. This study recommends adopting synthetic mulch and shade nets as sustainable practices for enhancing resilience and productivity in pistachio orchards, particularly in saline, hot, and water-stressed regions.