Pathogenicity of MELOIDOGYNE EXIGUA on coffee (COFFEA ARABICA) in pots


  • M. Di Vito
  • R. Crozzoli
  • N. Vovlas


Coffea arabica, coffee, histopatology, Meloidogyne exigua, pathogenicity, root-knot nematode, tolerance limit


The relationship between a geometric series of fourteen initial population densities (Pi) of Meloidogyne exigua between 0 and 512 eggs and juveniles/cm 3 soil and growth of coffee (Coffea arabica) was investigated in one-liter clay pots. The Seinhorst model, y = m + (1 - m)z P-T, was fitted to average plant height, internode length, and fresh top weight. Tolerance limits (T) to the nematode for height, weight and lengths of internodes of coffee plants were 5.9, 1.2 and 6.2 eggs and juveniles/cm*3 soil, respectively. The minimum relative yields (m) were 0.7 and 0.4 at Pi*3 256 eggs and juveniles/cm*3 soil for height and internode length of plants, respectively, and 0.5 at Pi*3 128 eggs and juveniles/cm*3 soil for plant top weight. Maximum nematode reproduction was 422-fold at lowest initial population densities (Pi). The histopatology of coffee roots infected by M. exigua reveals swollen root tips and axes. Nematode egg masses were visible on root surfaces only in small root-galls whe