Indução de resistência em plantas de pimentão (Capsicum annum L.) utilizando acibenzolar-S-metil no controle da antracnose

Abstract

The bell pepper (Capsicum annum L.) crop is one of the most important vegetables grown in Brazil, and has been showing significant growth. However, this culture can be affected by a number of diseases that cause economic damage and anthracnose, still represent a serious obstacle to production, both in the field and at home-de-vegetation. Anthracnose in Capsicum annum can be caused by several species of fungi of the genus Colletotrichum, but in Brazil, the majority of reports identify Colletotrichum gloeosporioides as the main causative agent of the disease. Infections characterized in lesions aerial parts of the plants such fruits, stems and leaves. The control method of the infections is used in fungicidal applications, however currently search for more sustainable alternatives. Thus the use of resistance inducers has been outstanding and can be applied preventively, by acting on the physiological and biochemical processes of plants. Given the above, the objective of this study was to investigate the efficacy of acibenzolar-S-methyl inducer for the control of anthracnose in pepper plants as well as the activation of enzymes related to pathogenicity and they peroxidase, polifeniloxidase, catalase, ascorbate peroxidase and β-1,3-glucanase.. The study was conducted in a greenhouse in Garanhuns-PE municipality, and the treatments were arranged in subdivided portion, in which the portion consisted of collection times and the subplot of different inducer of doses, with four replications. The plants were treated with the treatments as follows: 0.15g L-1; 0.30g L-1; 0.45g L-1, 0.60g L-1 acibenzolar-S-methyl (Syngenta®) and control (distilled water only). The results were analyzed by the software program SAEG 5.0 to 5% probability. The peroxidase activity was not significant for analysis of variance at 5% probability, however the dose 0.45g L-1 promoted greater activity. For peroxidase although not significant ascorbate activity to analysis of variance, the dose 0.15g L-1 showed increased activity of this enzyme is superior to the control. The increase in catalase activity was significant when the plants were treated with the highest dose of 0.60g L-1 inducer. On the eighth day after inoculation was higher by polyphenol oxidase activity, standing out from the others collection times. The dose 0.60g L -1 promoted greater activity of β-1,3-glucanase enzyme. When the plants medium subjected to the application of acibenzolar-S-methyl there was a reduction in the severity as the doses increased, thereby showing that prior treatment with resistance inducer consists of an efficient method for control of anthracnose disease.