BACTERIAL WILT OF TOMATO IN CENTRAL C?TE D'IVOIRE: IDENTIFICATION OF THE CAUSAL AGENT AND CONTROL BY EXTRACTS OF ALLIUM FISTULOSUM AND HYDROCOTYLE BONARIENSIS

Tomato is one of the major new sources of income for many farmers in central C?te d?Ivoire. However Plant wilting undermines tomato cultivation in Central C?te d?Ivoire. The purpose of this paper is to help improve the production of that vegetable through both identification and non-chemically control of the causal agent of the bacterial wilt. During the phytosanitary survey, the disease prevalence and severity were determined in five tomato plantations in Yamoussoukro. The pathogen associated to bacterial was isolated and tested for pathogenicity. The sensitivity of the causal agent to the ethanolic extracts of Allium fistulosum and Hydrocotyle bonariensis was then evaluated using the well method and dissemination on SPA medium; subsequently applied on artificially infected plants. Several symptoms including leaf flaccidity, chlorosis, browning between veins, leaf drying and browning of the vascular system were observed. Prevalences ranged from 30 to 85% while severities ranged from 2.3 to 4.63. The bacteria Ralstonia solanacearum responsible for the disease showed high sensitivity to the ethanolic extract of A. fistulosum and a moderate sensitivity to H. bonariensis. On inoculated tomato plants, extracts of H. bonariensis and A. fistulosum brought down the prevalence of wilting by 31.67% and 35%, respectively. Control trials could be conducted in the field to determine the optimal doses of extracts that can substitute synthetic pesticides proven very expensive and relatively toxic for consumers.