Phytotherapeutic approach for the management of Meloidogyne incognita affecting Abelmoschus esculentus (L.) Moench

Abstract

Fresh leaf samples of Nicotiana plumbaginifolia, Wedelia chinensis, Cassia tora and Jatropha curcas, and flowers of W. chinensis, Catharanthus roseus and Calendula officinalis were evaluated for their hatching inhibitory and juvenile mortality potential and to ascertain their role as organic amendment for the management of root-knot nematode, Meloidogyne incognita affecting Okra (Abelmoschus esculentus). Four concentration levels i.e. S, S/2, S/10 and S/100 of aqueous leaf and flower extracts of test plants were prepared. All the extracts showed varied but significant results over control (Distilled water). The “S” concentration of aqueous flower extracts of C. officinalis and W. chinensis exhibited 100% mortality after 24 h exposure period. Similarly, larval hatching was completely inhibited by “S” concentration of extracts of all the tested plants except C. tora after five days of exposure period. All the flower extracts and N. plumbaginifolia leaf extract showed complete suppression at S/2 concentration. Increased dilution showed a direct effect on hatching but an inverse effect on mortality. The juvenile mortality increased with increase in exposure period. In pot trial studies, application of all the samples significantly enhanced the plant growth and decreased the host infestation by M. incognita over control. Among all the treatments, flowers of C. officinalis and leaves of Jatropha curcus proved to be the best.