Manejo pós-colheita de Colletotrichum gloeosporioides em manga ‘Tommy Atkins

Abstract

Anthracnose is the main disease in the culture of mango, caused by Colletotrichum gloeosporioides, Alternative forms to chemical control, routinely used, has been used to minimize costs and reduce waste. Among the alternatives, we highlight the use of inductors using plant extracts and other biological inducers. The objective was to evaluate the natural incidence of anthracnose in mango fruits treated with Momordica charantia and chitosan, the disease severity, as well as to evaluate the postharvest quality and the production of enzymes related to plant defense. The leaf of M. charantia were collected in the city of Areia-PB, Brazil, prepared in plant pathology lab on Campus II, UFPB, and forwarded to the Natural Products Chemistry Laboratory, Campus I, UFPB, for extraction ethanol. The treatments consisted of M. charantia extract at concentrations of 1000, 1500 and 2000 ppm chitosan in concentrations of 1%, 1.5% and 2%, the commercial product acibenzolar-S-methyl (ASM) (0.1 g.L-1 ), fungicide (Thiabendazole) (4 ml.L-1 ) and sterile distilled water (control), with four replications and three fruits per replication. Enzymatic assays were performed on the day of collection of fruit-eight days after treatment application, evaluating enzymes: peroxidase, polyphenol oxidase and phenylalanine ammonia lyase. The use of chitosan decreased the severity of anthracnose caused by C. gloeosporioides, compared to other treatments. On the incidence of diseases in mango fruits, both chitosan as ASM inhibited the emergence of pathogens. In enzymatic analysis, the peroxidase activity increased in all treatments compared with control. Only the treatments with chitosan, in all tested concentrations, such as M. charantia extract the highest concentration, results in an increase in PPO activity. Phenylalanine ammonia lyase activity has only been stimulated by treatment of 2% chitosan. The use of chitosan positive influence in post-harvest, and stimulated the production of all studied enzymes. The application of chitosan as an alternative treatment to conventional control is recommended.