Extratos vegetais no controle da antracnose em pimenta-decheiro (capsicum chinense jacq.)

Abstract

The Amazon is the center of diversity for the Capsicum chinense species, with sweet pepper being the most cultivated variety in the region, and present in local cuisine dishes. The emergence of anthracnose limits the production of vegetables and can lead to 100% loss in production. Fungicides are recommended for management, with the disadvantage of selecting resistant variants, contaminating the environment and affecting human health. Plant extracts arouse interest in the management of phytopathogens, as they have antimicrobial properties and biotechnological potential for the production of new compounds antifungals. The objective of this work was to study the use of crude and fractioned plant extracts of Croton Cajucara, Piper marginatum and Curcuma longa to inhibit mycelial growth, sporulation and germination of Colletotrichum sp. in vitro and in the control of anthracnose in sweet pepper fruits and to identify the main chemical compounds present in plant extracts. Experiments were conducted, with aqueous extracts and another with fractionated extracts, using leaves (C. cajucara and P. marginatum) and rhizome (Cur. longa) to extract the compounds. To obtain the aqueous extract, water at room temperature (cold extract) and at 70 ℃ (hot extract) was used. To obtain the fractions, extractions were performed with solvents, methanol, ethyl acetate and hexane. Hexanic (FH) and ethyl acetate (FAE) fractions of Cur. long, showed better potential in inhibiting fungal development and were selected for identification of major compounds. Aqueous and fractionated extracts were evaluated for the control of anthracnose in sweet pepper fruits. The results showed that there was no significant difference between treatments using aqueous extracts for mycelial growth and conidia sporulation. There was a reduction in the incidence of anthracnose by 33.3% and 41.7% using the extracts P. marginatum and C. cajucara and 100% for the extract of C. longa. In the fractionated extracts it was observed that the FH of C. longa were the most promising, inhibiting 59.2% mycelial growth, 49.8% conidia germination and reducing the incidence of anthracnose by 33.3%, and the identified compounds were ar-turmerone (48.71%) and ar -turmerol (11.51%) as compounds of the FH of C. long. The results show the potential of the extracts to control Colletotrichum sp. and anthracnose in sweet pepper fruits