Extratos de canola no controle da antracnose em banana

Abstract

Banana is one of the most popular and consumed fruit in Brazil and in the world, which origins is Asia. The anthracnose, caused by the fungus Colletotrichum musae, is also one of the most serious post-harvest disease that affects banana production. Aiming the use of alternatives products for diseases management, the objective of this study was to evaluate the effects of canola extract obtained from aqueous, maceration and infusion methods (12%) and the use of handmade sachet, containing canola in the doses 0, 6, 12, 18, 24 g, for anthracnose control, and evaluate the influence of canola powder in the number of fungus conidium. The in vivo experiments were conducted in the Phytopathology Laboratory at UniversidadeTecnológica Federal do Paraná. The bananas were obtained from the company known as Bananas Cobalchini. The fruits were washed and left on the stand over a paper towel until its surface dry up. Meanwhile, paper towel humidified with destilled water, was placed in trays, followed by PVC rings. In the first assay, the bananas were submerged in different types of canola powder extracts for one minute, and posteriorly the fruits were transferred to trays, where a mechanical injury was made for the inoculation of a C. Musaespore solution of 20 uL, which concentration was 1 x 106 conidia mL-1. After this procedure, the trays were closed and stored in a growing chamber for 7 days, under a temperature of 25 ºC.In the second assay, the same methodology was used. However, the fruits were not submerged in extracts. The sachet containing canola poderwas placed in the middle of the trays. The mechanical injury and inoculation were done as the same way described previously as well as the tray closing and the storage in the growing chamber. In the first assay was tested four treatments, with five repetitions and five fruit for each tray. In the second assay, was tested used five treatments, five repetitions and five fruits for each tray. After seven day, the lesion diameter of all fruits were measured using a caliper rule. For the conidia counting, the lesions of all fruits were rubbed off and washed with distilled water and transferred to Falcon tubes, adding Twenn and Lactophenol. The conidia were counted using a Neubauer chamber. The qualitative data were analyzed by analysis of variance and when they were significant, the data were compared by Tukey’s test (p< 0.05), and the quantitative data were analyzed by regression analysis. The results showed that in both assays there was not reduction of the lesion diameter of the fruits and in the number of conidia. In the second assay, the lesion diameters were bigger for doses 6, 12 and 18 g.