Study on Management of Root-Knot Nematode in Rice

Abstract

Rice is grown in diverse environments either as a sole crop (rain fed, irrigated or deep water) or as a major c01nponcnt in various cropping systcn1s. Rice cullivation cover large area in fndia. cvt!n a smaJJcst pest problem would have great in1pact on yield and farmers income. Soil borne diseases arc becoming very important in the rice-based cropping systems. One of the most important soil borne pest of Rice is plant parasitic nematode. About two hundreds nernatode species belonging to thirty five genera have been reported infesting rice. Among them, Meloidogyne gran1inicola (Golden and Birchfield) causing rice root knot disease has emerged as a major pest throughout the world due to its broad host range and ability of causes potential yield loss. The losses caused by !vf graminicola may vary from negligible to heavy depending on the severity of disease. The degree of ~ymptorrts such as yellowing, dwarfing and gall formation on the roots of rice plants manifestation differs with time of infection, age of the plants and load of inoculums. To prevent yield losses and improve productivity, it is necessary to find out the effective sustainable management strategy. Indiscriminate use of chemicals for managing this disease, results in the development of pathogen resistance and risk to the environment which has favored the introduction of various eco-friendly approaches of management. In present investigation plant extract, organic amendment and bio-agent (Trichoderma spp.) were used to evaluate their effectiveness in the management of rice root knot nematode. In pot experiment, neem leaf, neem kernel and aak leaf extract were found most effective in suppression of nematode gall formation on the rice root. In pots experiment neem leaf, neem kernel and aak leaf amended treatments, average 2.33, 4.66 and 4.66 galls/root system, respectively were observed. At the 60 DAS, neem kernel, aak leaf and neem leaf amended pots were recorded with 6.33, 7.33 and 7.66 galls/ root system respectively .In control 17.33gall/root system were recorded. These plant extracts were also tested under lab condition to check the nematicidal activity against J2 of M graminicola. The maximum (53.33% and 75.00%) larval mortality was recorded in neem leaf extract at 24 and 48 hrs after inoculation. In field experiment, organic amendments (Neem cake and Vermicompost) and Trichoderma spp. were used alone and in combination for the management of the rice root knot nematode. Application of combination of neen1cake+Vermicon1post+Trichoderma spp. was found superior in comparison to other treatment in suppression of root gall fonnation on rice root in field. In this combination 0.33 and 1.33 gal/root systems were observed at 30 and 60 day after transplanting, ,respectively. Whereas 16.00 & 17.66 gall/root system were recorded in the check plot at 30 &60 day. Result obtained in this in' esti,~Sl~if~. yi.~ ..- es that there is possibility of use of botanicals, organic amendments and bio-agents alone and in combinati ~-~!(>; tfie-managc .nt of nematode in rice crop.