Enhancing Sweet Cherry Yield and Quality Under Drought Stress Through Melatonin Foliar Spraying

The study investigates the efficacy of foliar spraying with melatonin at various concentrations (100, 200, and 300 µM) on the quantitative and qualitative attributes of Takdaneh Mashhad cherry subjected to different irrigation levels (100%, 75%, 50%, and 25% of soil field capacity (FC)) in Safadasht, Tehran over two years. Results reveal that drought stress significantly reduced cherry tree yield, with severe stress (25% FC) causing notable decreases in fruit weight (17%), kernel weight (9%), juice pH (11%), juice volume (15%), leaf nitrogen (28%), leaf phosphorus (41%), and leaf potassium (25%). However, melatonin application, particularly at 200 µM, mitigated water stress effects by enhancing both biochemical and morphological fruit characteristics. Elevated levels of leaf elements (N, P, and K) and anthocyanin were observed in melatonin-sprayed trees. Thus, the findings suggest that melatonin application, coupled with reduced water to 75% FC, offers a viable approach for optimizing sweet cherry crop production under water-limited conditions.