Oil seed cakes of neem/margosa (Azadirachta indica), castor (Ricinum communis), mustard (Brassica compestris), rocket salad/duan (Eruca sativa) were found to be highly effective in reducing the multiplication of nematodes and consequently plant growth and bulk density of woody stem of pigeonpea increased significantly. The multiplication rate of nematodes was less in presence of Paecilomyces lilacinus as compared to the absence of P. lilacinus. Damage caused by the nematodes was further reduced when P. lilacinus was added along with oil-cakes. Most effective combination of P. lilacinus was with neem cake.

The root-knot nematode, Meloidogyne incognita caused greater reduction in plant growth, chlorophyll content, water absorption capacity of roots and root nodulation of chickpea and pigeonpea and bulk density of pigeonpea stem, than the reniform nematode, Rotylenchulus reniformis. These nematodes inhibited each other in concomitant infections. However, both the nematodes together caused more damage to the test plants than was caused by either of them singly, but it was less than the sum total of the damage caused by them individually. Oil-seed cakes of neem/margosa (Azadirachta indica), castor (Ricinus communis), mustard (Brassica campestris), rocket salad/'duan' (Eruca sativa) were found to be highly effective in reducing the multiplication of nematodes and consequently plant growth, the water absorption capacity of the roots, root nodulation and bulk density of woody stem of pigeonpea increased significantly. The test nematodes were found to be less damaging in the presence of Paecilomyces lilacinus. The multiplication rate of nematodes was less in presence of P. lilacinus as compared to the absence of P. lilacinus. Damage caused by the nematodes was further reduced when P. lilacinus was added along with oil-cakes. Most effective combination of P. lilacinus was with neem cake.

No abstract

Pigeonpea (Cajanus cajan) and linseed (Linum usitatissimum) are susceptible to Meloidogyne incognita and Rotylenchulus reniformis nematodes. Reduction in different growth parameters (length and weight of plant, number of pods), bulk density of pigeonpea stem, oil content of linseed, chlorophyll content of leaf and water absorption of roots caused by M. incognita and R. reniformis were statistically significant. Similar effects were also observed in plants raised from seeds soaked in different concentrations of water soluble fractions (WSF) of rice polish and pyridoxine solutions, however, the reductions were of a comparatively lesser extent. Higher concentrations of the solutions were more effective when compared to lower ones and pyridoxine was more beneficial than WSF for improving plant growth and reducing disease incidence.

Seed dressing with culture filtrate of Paecilomyces lilacinus resulted in a significant control of root-knot nematodes, Meloidogyne incognita and reniform nematode, Rotylenchulus reniformis singly or concomitantly, with a corresponding increase in plant growth, length and weight of plants and number of pods, chlorophyll content of leaves, water absorption capacity of roots of okra (Abelmoschus esculentus). In another experiment soil application with oil cake of neem (Azadirachta indica) showed significant suppression of the nematodes, both singly as well as concomitantly, with the consequent improvement in different growth parameters of the plants as above. A combination of seed dressing treatment with culture filtrate of P. lilacinus and soil amendment with neem cake gave synergistic effect with respect to nematode management and improvement in plant growth parameters.