Kavita Parihar

Bio-efficacy of some leaf extracts on the inhibition of egg hatching and mortality of Meloidogyne incognita

Nematicidal activities of extracts from plants were assayed against Meloidogyne incognita in vitro. Leaves of six different plants were collected in and around Aligarh Muslim University Campus. Aqueous extracts of six plants were screened for egg hatchability and nematicidal activity against second stage juveniles of M. incognita in the plant pathology and nematology laboratory, AMU Aligarh. The nematode egg and juveniles were exposed 12, 24 and 48 h in (S, S/2, S/10, S/100) concentrations of plant extracts. The plant extracts of leaves of six plants species viz. Jatropha pandurifolia, Polyalthia longifolia, Wedelia chinensis, Nerium indicum, Duranta repens and Cassia fistula exhibited highly promising mortality of 99.00–72.00% after 48 h of exposure. Aqueous extracts of leaves of J. pandurifolia, P. longifolia, W. chinensis were recorded to be highly effective for inhibition of egg hatching and increasing juvenile mortality of M. incognita. There was a gradual decrease in egg hatching and increase in mortality rate of juveniles of M. incognita with increase in the concentration of leaf extract and exposure time.

Role of Oil Cakes and Pochonia chlamydosporia for the Management ofMeloidogyne javanica Attacking Solanum melongena L

A pot experiment was conducted to evaluate the efficacy of Pochonia chlamydosporia, oil cakes of neem, mustard and cotton and nematicide (carbofuran) in the management of root knot nematode, Meloidogyne javanica infecting brinjal under glasshouse conditions. All the treatments were effectively suppressed the nematode population and kept the infection at significantly low levels. Among oilcakes individual treatment of neem was more effective than other oil cakes in controlling M. javanica, whereas among combined treatment, neem cake+P. chlamydosporia was more effective in the management of M. javanica followed by mustard cake+P. chlamydosporia and cotton cake+P. chlamydosporia. However, the efficacy of P. chlamydosporia increased in the presence of oilcakes. Oilcakes when combined with nematicide (carbofuran) showed best results in terms of plant growth parameters, reduce root knot diseases and nematode multiplication after combining with P. chlamydosporia. These organic amendments are capable of producing secondary metabolites, which have an allelopathic effect and induces plant resistance against the invasion of nematodes. This approach is non hazardous, cheaper and easily available to the farmers.

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

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.