Studies on management of rice root knot nematode (Meloidogyne graminicola) in the nursery of basmati rice

Abstract

Present investigation was carried out in lab and field condition for the management of root knot nematode (Meloidogyne graminicola) in rice nursery. In vitro efficacy of different plant extracts viz., Bhang (Cannabis sativa), Guldaudi (Chrysanthemum indicum),Malabarnut (Justicia adhatoda), Ashwagandha (Withania somnifera) , Kaner (Nerium oleander), Neem(Azadirachta indica), Bhringraj (Eclipta prostrate), Peach (Prunus persica) and congress grass (Parthenium hysterophorus) were tested at 2 % and 4 % concentrations against larval mortality and egg hatching of rice root knot nematode under laboratory condition. At 4 % concentration, maximum (48.35 %) larval mortality was recorded in Peach (P. persica) after 72 hours of inoculation. In case of egg hatching at 2 % concentration, minimum (60.00 %) egg hatching was recorded in Neem whereas, at 4 % concentration, minimum (53.35 % ) egg hatching was recorded in Neem (A. indica) after 72 hours of inoculation. Pot experiment was conducted to test the efficacy of nematicides viz., Phorate 10G, Furadan 3G and Nimitz were applied as soil and seed treatments against root knot nematode. Minimum (2.11 and1.56) galls/plant were recorded in soil application of Phorate 10-G @ 0.4 g/kg of soil in the years 2020 and 2021 at 60 days after sowing. In case of growth parameters, maximum root length (9.83 and 11.78 cm) and maximum shoot length (58.44 and 48.61 cm) was recorded in treatment soil application of Furadan-3G @ 0.4 g/kg of soil in years 2020 and 2021 respectively, at 60 days after sowing. Field experiments were conducted to test the efficacy of bio-agents against the root knot nematode in rice nursery during 2020 and 2021. Minimum (10.56 and 14.78 galls/plant) in Phorate 10-G @ 2.5 g/m2 of soil followed by (13.11 and 15.22 galls/plant) in Trichoderma S13 @ 20g/m2 of soil was recorded after 60 days of seed sowing. In-vitro study was carried out to check the compatibility of nematicides with bioagents. At 72 hours of inoculation, maximum 82.70, 85.33 and 88.71 mm mycelial growth was recorded in Trichoderma isolate S13 in Furadon-3G 750 μg/ml, Phorate 750 μg/ml and Nimitz 750 μg/m respectively. In case of Bacillus subtilis, Nimitz 250 μg/ml was found more compatible than other tested nematicides. Minimum (38.33 mm) inhibition zone of Bacillus subtilis was recorded with Nimitz 250 μg/ml. Pot experiment was conducted during 2022 and 2021 to test the efficacy of different organic amendments in combination of bio-agents. Among all the treatments, minimum 2.67 and 1.56 galls/plant was recorded in FYM @ 20 g/kg of soil + Trichoderma isolate S-13 @ 5 g/kg of soil after 60 days after sowing during both the years. Pot experiment was conducted to test the effect of different levels of inoculum of root knot nematode on galls formation and plant growth parameters of rice. In the year 2021, maximum (18.11 and 30.56) galls/plant were recorded on inoculation of 1000 J2/kg of soil at 30 and 60 day after sowing, respectively. On the basis of present study, native isolate Trichoderma isolate S-13 was found most effective to reduce the galls formation and enhance the growth parameters of rice plant.