In Brazil, the most important disease in cassava crop is bacteriosis, which is caused by Xanthomonas axonopodis pv. manihotis, The variety of substances found in plants has provided an increase in experiments using plant extracts, for in vitro control of phytopathogens. The objective of this work was to evaluate different extracts for the control of Xanthomonas axonopodis p.v. manihotis as well as to evaluate the accessions that are susceptible to this bacteriosis. The work was divided into two experiments, one in a greenhouse and the other in a laboratory, both in a completely randomized design with five replications. The extracts of propolis, oregano and star anise tested in this work were found to be a control option. The understanding of the antimicrobial effect of compounds present in plant extracts may constitute in another way of alternative control of pathogens from cultivated plants. In relation to cassava accessions, it is recommended to use the cultivar Fepagro RS14 and the accessions FV10, FV13 and SJ06 as they were proved to be resistant to bacteriosis.

Keywords: Alternative control; bacteriosis; genetic resistance.