www.IndianJournals.com Members Copy, Not for Commercial Sale Downloaded From IP - 45.116.204.2 on dated 30-May-2017 Journal of Progressive Agriculture, Vol ,2 No.3: October 2011 74 Bioefficacy of different Populations of Steinernema carpocapsae against Root Knot Nematode Meloidogyne incognita A.K. MARU, A.U. SIDDIQUI, A. PARIHAR AND S.K. SHARMA Department of Nematology, Rajasthan College of Agriculture, MPUAT, Udaipur (Raj.) Email: maruajay@gmail.com Bioefficacy of different populations of Steinernema carpocapsae was studied against Meloidogyne incognita in laboratory condition as well as in pot condition. The mean percent mortality of M. incognita second stage juveniles were recorded after every 6 hrs intervals upto 72 hrs at different inoculum levels viz., 5, 10, 15 and 20 IJs of EPNs per cavity block in laboratory condition. Maximum (20.62) mean per cent mortality was observed with S. carpocapsae STSLU@ 20 IJs per cavity block after 72 hrs. Bioefficacy of the S. carpocapsae against M. incognita was also studied in pot condition. Maximum (37.79 cm) shoot length, (30.00 g) shoot weight, (31.79 cm) root length, (12.61g) root weight and minimum (22.83) galls per plant, (10.69) eggmasses per plant, (232) eggs and larvae per eggmass and (507.38) larvae per 200 cc soil were recorded with S. carpocapsae STSLU @ 20,000 over all other treatments. Key words: Steinernema carpocapsae, Meloidogyne incognita, Bioefficacy, inoculum. The entomopathogenic nematodes have also been found effective against plant parasitic nematodes. Grewal et al., 1996 have used S. carpocapsae and S. riobravis successfully against plant parasitic nematodes infesting turf grass. EPNs have been found compatible with nematicides in suppressing plant nematodes when used as a component in integrated nematode management (Glazer et al., 1997). Entomopathogenic nematodes are effective for the management of root knot nematodes (Grossman, 1997). S. glaseri suppressed penetration and reduction in egg production of M. incognita in tomato roots (Perez & Lewis, 2004). In view of the above, the present investigations have been selected indigenous populations of EPNs and to evolve a newer and environmentally safer tactics for the management of root knot nematodes. MATERIALS AND METHODS Bioefficacy of different populations of S. carpocapsae against root knot nematode M. incognita were carried out under laboratory as well as pot conditions. In laboratory condition: Sterilized cavity blocks were kept in sequence according to treatments and replications, 2 nd stage IJs (20) of M. incognita were placed in each cavity block. The suspension consisting IJs of different populations of EPNs stored in sterile distilled water were first examined under stereoscopic binocular microscope to check the activity of the juveniles and diluted with known quantity of sterile distilled water for making the suspension as per the required number of IJs and inoculated in each cavity block and observations were taken on percent mortality of second stage infective larvae of M. incognita after every 6 hrs. interval up to 72 hrs. The details of the treatments were as follows: Treatments: T 1 – S. carpocapsae STSLU T 2 – S. carpocapsae STUDP-1 T 3 – S. carpocapsae STUDP-2 T 4 – control Doses (Number of IJs of EPNs strain/cavity block): t 1 – 5 IJs t 2 – 10 IJs t 3 – 15 IJs t 4 – 20 IJs n = 20 II stage IJs of M. Incognita In pot condition Bio efficacy of different populations of S. carpocapsae was studied against M. incognita on tomato under pot condition. The details of the treatments were as follows: Treatments: T 1 – S. carpocapsae STSLU T 2 – S. carpocapsae STUDP-1 T 3 – S. carpocapsae STUDP-2 T 4 – associated check T 5 – control Inoculums levels (Number of IJs of EPNs/pot): t 1 – 5000 IJs t 2 – 10000 IJs t 3 – 20000 IJs The IJs of different populations of S. carpocapsae were stored in sterile distilled water (SDW) and were examined under stereoscopic microscope, and active juveniles were diluted in known quantity of SDW for making the suspension according to required number of IJs. The IJs were applied at different inoculum levels at the rhizosphere of the tomato plants. Carbofuran 3G @ 2 kg a.i./ha as associated check and control as untreated check were taken. Before the application of EPNs 2.5 larvae of M. incognita per c.c. soil were maintained in pots and these observations were recorded after 45 days, on shoot length, shoot weight, root length, root weight, number of galls per plant, number of eggmass per plant, number of eggs and larvae per eggmass and nematode populations per 200 cc soil were recorded. The experimental results showed that all the treatments significantly increased the plant growth over untreated control. RESULTS AND DISCUSSION The experimental results (Table-1) revealed that S. carpocapsae STSLU showed maximum (20.62) mean per cent mortality followed by S. carpocapsae STUDP-2