Resistance of tomato varieties to the root-knot nematode Meloidogyne javanica in Cyprus

Abstract

The root-knot nematode, Meloidogyne javanica (Treub) Chitwood, causes economic losses to many vegetable crops. It is a serious pest of tomatoes in Cyprus (Taylor, 1965) where the crop provides an annual income to farmers of about £ 1.9 million. (Anon., 1973). Chemical control of the nematode in Cyprus has proved successful (Philis, 1974). Nevertheless, the use of high yielding root-knot resistant tomato cultivars could provide a useful additional method of combating losses, especially in fields with severe root-knot nematode infestations. This paper describes work undertaken to select high yielding cultivars resistant to M. javanica. Taylor (1967) expressed plant resistance to nematode attack on the basis of ability of the parasite to reproduce. Dropkin (1969) reported that resistance to Meloidogyne broke down in some plants when the temperature had risen above 28° C, suggesting that such changes presumably occur under natural conditions if plants are exposed to prolonged hot weather, while Peacock (1959) reported that resistant varieties can also be attacked but at a lower degree than susceptible ones. Southey (1965) reported that estimates of resistance cannot be based on degree of galling alone without reference to the reproduction rate of the parasite.