Invitro Efficacy of Different Warburgia Ugandensis Organic Crude Extracts Against Tomato Phytophthora Infestans and Alternaria Solani

Abstract

Alternaria solani and Phytophthora infestans are causative agents of early and late blight of tomatoes respectively and are currently controlled using fungicides. Use of inorganic chemicals is increasingly being discouraged due to safety challenges to consumers, pathogens resistance, environmental pollution and accumulation of residues in plants. Tomato production plays a vital role in meeting domestic and nutritional food requirements, generation of income, foreign exchange earnings and creation of employment. This study investigated the invitro efficacy of Warburgia organic solvent crude extracts on blight pathogens. Warburgia ugandensis stem bark sample was air dried at room temperature then ground. Powdered material was weighed and soaked in organic solvent then filtered and the solvent recovered using a rotary evaporator. Multiple extraction method was used with four organic solvents. Well diffusion method was used to screen Warburgia extracts against A. solani and P. infestans. All assays were performed in triplicate. Statistical analysis on inhibition zone was carried out using analysis of variance (ANOVA). Warburgia ugandensis hexane crude extract had the highest inhibition zone in A. solani while methanol crude extract gave the highest mean inhibition zone in P. infestans. All extracts were inhibitive against P. infestans and A. solani. Further research is required on invivo studies and analysis of bioactive compounds in the extracts.