Wilt diseases of tomato (Lycopersicum esculentum) and chilli (Capsium annum) and their management strategies: Emphasis on the strategies employed in Sri Lanka: A review

Wilt is one of the major diseases causing economic losses in many crops. It is caused by infections of many bacterial (Ralstonia solanacearum), fungal (Fusarium spp., Vertcillium spp., Rhizoctonia spp., Sclerotium spp.), oomycete (Pythium spp., Phytophthora spp.) and viral (Tomato spotted wilt virus) pathogens. This review provides an overview on the control strategies used in other countries for the wilt disease in highly susceptible vegetable/fruit crops; tomato and chilli and make comparisons with Sri Lanka. Many studies have been performed on the prevalence, severity, pathogenicity and the control of these infections in both crops worldwide. Wilt in tomato is caused mainly by Ralstonia solanacearum and Fusarium oxysporum and in chilli mainly by Fusarium oxysporum. Tomato bacterial wilt is successfully managed through usage of resistant cultivars, grafting, biological control agents, inducing host systemic resistance and integrated management. Tomato and chilli wilt caused by Fusarium sp. have been successfully controlled mainly through the application of chemicals and biological approaches such as systemic defense induction and the use of microbial antagonists. In Sri Lanka, tomato wilt is reported as being the result of bacterial, fungal and viral infections which have been mainly controlled by the usage of resistant cultivars, physical measures and cultural practices. Chilli wilt in Sri Lanka has not been thoroughly studied yet. But application of fungicides has been an effective strategy for fungal wilts. Wilt threat of tomato and chilli in Sri Lanka has to be further studied for the proper management of these infections and for freeing tomato and chilli cultivations from the wilt disease.