Atividade antibacteriana de óleos essenciais e extratos vegetais sobre o desenvolvimento de Ralstonia Solanacearum em mudas de bananeira

this study aimed to evaluate the activity of different concentrations of essential oils and plant extracts to the control of ralstonia solanacearum. different concentrations of the following essential oils were evaluated: citronella, eucalyptus citriodora, clove and ginger: 1.25%, 3.5%, 3.75% and 5%, respectively. the extracts evaluated were from clove, ginger, cinnamon and s？o caetano melon: 5%, 10%, 15% and 20%, respectively measuring the halo of inhibition of bacteria after 48 hours. the treatments with eucalyptus oil and extracts of s？o caetano melon, clove and cinnamon did not differ from the control. the extract of ginger and the oils of citronella, clove and ginger inhibited the growth of r. solanacearum in all concentrations tested. clove oil was the best treatment, followed by extract of ginger. seedlings of banana were sprayed with citronella and cloves oils (3.75%), ginger oil (3.75%) and extract of ginger (20%), 10 ml of each solution per plant. after eight days the seedlings were inoculated with the pathogen (108 cfu/ml). the citronella oil provided the best result, with 100% control of the disease, but the leaves showed symptoms of phytotoxicity. the oil and extract of ginger were similar in effectiveness of moko control (50%), and cloves oil showed lower efficiency (25%).