Pathogenesis of Meloidogyne javanica on cucumber and okra in sailne soils

Effects of artificially created soil salinity levels by addition of NaCl and NaHCO₃ in soil were studied on penetration and development of root-knot nematode, Meloidogyne javanica in the roots of cucumber and okra. Penetration of second-stage juveniles incucumber and okra roots and development of juveniles into adult females were impaired by the salinity levels. A direct correlation existed between concentration of the salts and number of root-ingressed juveniles. Production of egg masses was delayed and their number was significantly reduced. Plant growth of cucumber and okra was suppressed by thesoil salinity levels. M. javanica also caused marked reduction in plant growth. But underthe soil salinity stresses, the extent of reductions in growth parameters caused by the nematode was reduced and consequently the plant growth was comparatively better than those inoculated with the nematode alone. The soil salinity impeded nematode growth and reproduction which in turn reduced the harmful effects of the nematode on plants.