Growth, Nutrient Status, and Yield of Grapevines as Influenced by Foliar Melatonin

Grapevine fruit is a prevalent fruit grown in many countries around the world. Melatonin is a chemical that is naturally present and acts in various physiological processes in plants. The exogenous application of melatonin was studied to improve vine grape's growth and nutrient status to increase its yield. In the present study, 2-year field experiments were conducted to test the effects of melatonin on table grape yield. Foliar application of melatonin was made at three concentrations (0, 3, and 6 mg/L) in three stages: at flowering, pre-veraison, and veraison phase. The results revealed that melatonin applications at 3 and 6 mg/L led to a significant increase in leaf content of total carbohydrates by 24.13 and 26.13%, cluster length by 22.80 and 24.16%, cluster diameter by 17.22 and 19.25%, cluster weight by 35.91 and 40.37%, and total yield by 40.24 and 53.71%, respectively. Among all the treatments, melatonin at 6 mg/L was the best regarding the growth and yields of grape cv. Halawani.. KEYWORDS :Grapevines, Melatonin, Foliar application, Nutrition, Yield