Bio-fabrication of ZnO nanoparticles in Trachyspermum ammi L. Sprague seeds Extract and its Application to control Rot Disease of Okra Pods

Abstract

Quality of okra pods is affected by different biotic stresses during growth, harvesting and storage. Due to fungal attack, huge losses of its quality and quantity are observed. The present research was designed for the diagnoses and management of postharvest rot disease of okra pods. Infected okra pods were collected, and the disease causing agent was identified as Fusarium oxysporium. To control this disease Trachyspermum ammi L. Sprague seeds extract mediated nanoparticles were used. Here in metabolites filtrate of T. ammi was used to reduce zinc acetate into zinc oxide nanoparticles (ZnO NPs). The physiochemical and morphological characters of NPs were determined. Before their application to control Fusarium rotting of okra pods, fabricated ZnO NPs were characterized. X-ray diffraction depicted Nano-size T. ammi seeds extract mediated ZnO NPs (26.7). UV vis spectroscopy displayed absorption peak of ZnO NPs on 390 nm indicating successful reduction of zinc acetate in metabolites of plants seeds extract. Fourier transform infrared (FTIR) spectroscopy showed the presence of reducing and stabilizing chemical compounds (alcohol, carboxylic acid, amines, and alkyl halide. NPs showed variable antifungal activities at four different concentrations (0.25, 0.50, 0.75 and 1.00 mg/ml). Diseases control and postharvest changes in okra pods were analyzed for 15 days. Among all treatments, 1.00 mg/ml concentration of ZnO NPs and 0.75 mg/ml concentration of ZnO NPs Showed the strongest antifungal activity. Application of ZnO NPs reduce okra pods decay, weight and preserved firmness of disease okra pods These nanofungicides were made in powder form and they can be easily transferred and used in the field to control Fusarium rotting of okra pods. Our results conclude that T. ammi seeds extract based synthesized ZnO NPs can efficiently control fruit rot, enhance shelf life, and preserve the quality of okra pods.