Variation in development and infectivity among populations of Meloidogyne hapla on four tomato cultivars and other host plants


  • Z. A. Stephan


In many areas of the world root-knot nematodes Meloidogyne spp., are important pests of crops. The different species of Meloidogyne are known to differ in their host range, and non-host crops are often used to reduce popubtions before a susceptible crop is grown. Resistant cultivars have also been bred in some crop species and can be used to reduce Meloidogyne populations. In tomato (Lycopersicon esculentum Mill.) more than 120 cultivars have been produced with resistance to Meloidogyne spp. and some (e.g. Nemared, Rossol, Small Fry) combine resistance to three Meloidogyne spp. (M. javanica, M. incognita, and M. arenaria) (Fassuliotis, 1979; Hadisoeganda and Sasser, 1982). However, it is known that this resistance is often less effective against some populations or races than against others (Sasser, 1963). This paper describes the use of 4 tomato cultivars (1 susceptible, 3 resistant), and 5 other crop plants to measure the variation in infectivity and development of 5 populations of M. hapla.