Soil amendment with halophytes induces physiological changes and reduces root-knot infection in eggplant and okra

Root-knot nematode, Meloidogyne javanica (Treub) Chitwood is a soil-borne plant pathogen of roots. Nematode infection results in altered plant growth and physicochemical processes due to gall formation. Many plants contain unique biochemicals that have biocidal properties and offer a potential novel approach to suppress the nematode populations in soil and improve growth of crop plants. In the present study effect of some indigenous halophytic plant species ( Tamarix indica Willd , Suaeda fruticosa Forssk and Salsola imbricata (Schultz) Dandy) were tested against M. javanica . Tested halophytes significantly ( P< 0.001) reduced egg hatching and caused mortality of second stage juveniles (J 2 ) in vitro . These halophytes when incorporated in soil (0.3, 0.5 and 1% w/w) markedly increased growth of eggplant ( Solanum melongena L. cv. Black beauty) and okra ( Abelmoschus esculentus [L.] Moench. cv. Arka anamika) and provided control of root-knot infection at higher doses (0.5 and 1%). Amended eggplants and okra showed significant ( P< 0.001) increase in chlorophylls and decrease in chlorophyll a/b ratio. Protein concentration in leaves of both the plants were increased with 1% amendment of S. fruticosa and S. imbricata . While nucleic acid concentrations were varied with different treatments.