Comparison of concomitant and sequential inoculation of Steinernema sp. in the management of Reniform (Rotylenchulus reniformis) nematode infecting eggplant

Abstract

Culture of Steinernema sp. was maintained on Corcyra cephalonica. Steinernema sp. was then formulated on calcium alginate capsules. Steinernema sp. were concomitantly inoculated @ 50, 500, 1000, 2500, 5000, 10,000 and 20,000 ij’s / 500 g soil with 500 immature females of R. reniformis / 500 g soil in pots having eggplant seedlings. The simultaneous inoculation of R. reniformis with either of the inoculum levels (1000, 2500, 5000 and 10,000 J3 / 500 g soil) of Steinernema sp. significantly reduced the damage caused by R. reniformis in terms of plant growth parameters viz., plant length, dry weight, number of flowers and weight of fruits. Moreover, the highest improvement in plant growth parameters viz., plant length, dry weight, number of flowers and weight of fruits was recorded in plants inoculated with 5000 J3 of Steinernema sp. / 500 g soil followed by 2500, 1000 and 10,000 J3 / 500 g soil. The highest reduction in the reproduction factor (Rf) was recorded in the plants treated with 5000 J3 Steinernema sp. / 500 g soil followed by 2500, 1000 and 10,000 J3 / 500 g soil. Comparison of concomitant and sequential inoculations showed that the sequential inoculation (both prior and post) of Steinernema sp. at different inoculum levels (1000, 2500, 5000, 10,000 and 20,000 ij’s / 500 g soil) were more effective in the management of reniform nematode than the concomitant inoculation. Therefore, the application of Steinernema sp. might be useful for suppression of nematode pest on eggplant and may be used as an alternative to chemical use