Phytochemical screening of plant extracts and control of mango stem-end rot

Abstract

This study aimed to evaluate aqueous extracts of melão-de-são-caetano, garlic, and mango cv. Tommy Atkins peel in order to detect the chemical molecules classes and evaluate the antifungal effect of the extracts in mango protection, against stem-end rot caused by Lasiodiplodia theobromae. The extracts were obtained from the dry parts of each plant, ground and added with sterilized distilled water as extractant. The analyses of the molecules were made by chromatography, using different mobile phases and proper reagents for the characterization of the substances classes present in the extracts. Healthy mangoes were immersed for five minutes in each concentration (25%, 50% and 75%) of the extracts. Immediate inoculations (106 conidia mL^-1) were made 12 and 24 hours after each treatment. The control treatment consisted of inoculated mangoes only, without treatments. The
evaluations were made every 24 hours until the fourth day, for each inoculation period, by measuring the size of the lesion. The area under the disease severity progress curve (AUDSPC) was calculated, and the means were tested with the Skott Knott test at 5% probability. The phytochemical analysis revealed groups of secondary metabolites in each extract, which proved to be efficient for the control of stem-end rot in post-harvest mango.