Incidence of Tomato spotted wilt virus on tomato (Lycopersicon esculentum) varieties infected by natural field infection of thrips

Abstract

Tomato spotted wilt virus (TSWV) is a major constraint to tomato production in Kenya. Symptoms of tomato spotted wilt differ among hosts and can be variable in a single host species. Common symptoms of TSWV infection include stunting, which is more severe when young plants are infected, and chlorotic or necrotic rings on the leaves and fruits. Management of the primary vectors of the virus disease, the western flower thrips (Frankliniella occidentalis Pergande) and tobacco thrips (F.fusca and F.bispinosa) is the main factor underlying management of the disease. A study was conducted with the objective to screen five tomato varieties (Cal J, Marglobe, Money Maker, Roma, and Riogrande) for resistance to TSWV by thrips-mediated infection in the field. Infection lowered yield and fruit quality. Variety Roma was the most tolerance under natural field infection. Metasystox insecticide significantly suppressed thrip populations under field condition.