Antimicrobial activities of cascalote (Caesalpinia cacalaco) phenolics-containing extract against fungus Colletotrichum lindemuthianum

Cascalote (Caesalpinia cacalaco) is a tree located in Pacific Mexican coast, and it is an excellent source of phenolics as gallic and tannic acids used in Mexican tannery industry, and with a potent antioxidant and antimutagenic activities. Based on the phenolics properties, these compounds present potential antimicrobial activity against a myriad of microorganisms. Thus, in this study it was evaluated the antimicrobial activity of cascalote phenolics against phytopathogenic fungus Colletotrichum lindemuthianum which causes anthracnose disease in common beans (Phaseolus vulgaris). The results indicate that cascalote phenolics have in vitro fungistatic activity against C. lindemuthianum races R-0 and R-1472. Moreover, these compounds provoked on the whole, in vitro inhibition of spores germination and cellulase and polygalacturonase activities in these fungi. In vivo assays with cascalote phenolics under greenhouse conditions using susceptible cv. PI 206272 of common bean resulted in a good protection against anthracnose severity especially as a preventive treatment. Several aspects of the results and implications on the potential use of cascalote phenolics as organic antifungal are discussed.