Application of Melatonin and Sodium Nitroprusside to Enhance the Physiological and Morphological Characteristics of Pepper

Heat stress arises when temperatures exceed a critical threshold for a specific duration during various stages of plant development. Consequently, it is crucial to devise effective strategies to overcome this obstacle in crop production. This research investigates the impact of melatonin and sodium nitroprusside on enhancing the heat resistance of Capsicum annuum. The Wonder cultivar of Capsicum annuum underwent various temperature treatments (25, 35 and 40°C) for a duration of 24h subsequent to being sprayed with melatonin and sodium nitroprusside at concentrations of 50 μM and 100 μM. The findings indicated that the application of melatonin during a temperature treatment resulted in an enhanced efficiency of leaf water consumption (16 percent). Additionally, pepper plants exposed to the same temperature treatment and treated with 100 µM melatonin exhibited a significant 13.5 % increase in fruit dry weight compared to the control group. The application of melatonin and sodium nitroprusside resulted in enhanced fruit characteristics and fruit marketability characteristics decreased. When exposed to a temperature of 40°C, there was a reduction of 18.50 % in the fruit's total soluble solids (TSS) compared to the control temperature of 25°C.