Occurrence, population fluctuations and management of root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood in pomegranate orchards in Kullu (Himachal Pradesh), India

This study was conducted in Nauni, Solan (Himachal Pradesh), India, between 2019 and 2020. Experiments on seasonal fluctuation in root-knot nematode population, Meloidogyne incognita in pomegranate orchards and its control were carried out at the Regional Horticultural Research and Training Station (RHR&TS), Bajaura, District Kullu, Himachal Pradesh. Estimation of M. incognita juvenile population in soil samples collected from 16 localities in three blocks of Kullu district viz., Kullu (6), Naggar (4) and Banjar (6) revealed prevalence of root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood in pomegranate orchards. The highest population of M. incognita (1696 juveniles 200 mL^‑1 soil) was noted in Dhaman village (Banjar block), followed by Shareuli, Jarad, Larji, Bajaura, Sainj, Shamshi, Targali, Balh, Babeli, Jia, Dobhi, Thrass, Katrain, Sharai and Duada localities with 1036, 864, 840, 840, 750, 340, 240, 210, 180, 160, 154, 135, 100, 100 and 70 juveniles 200 mL^‑1 soil, respectively. Population build-up of M. incognita in soil exhibited a significant and positive correlation with minimum temperature (r=0.92), with the highest population recorded during August (337.5 juveniles 200 mL^‑1 of soil) in pomegranate orchards at RHRS, Bajaura, District Kullu, India. Testing of different chemicals against M. incognita revealed juvenile mortality increased significantly with an increase in exposure period, with abamectin (0.00038%) causing significantly higher mean juvenile mortality (93.75%), followed by 83.23, 50.33, 40.28, 34.53 and 34.28% juvenile mortality in abamectin (0.00019%), fluazaindolizine (0.025%), fluopyram (0.05%), fluopyram (0.025%) and fluazaindolizine (0.0125%), respectively, under laboratory conditions. Abamectin and fluensulfone were also effective in preventing yield losses in pomegranate from root-knot nematode, M. incognita, under field conditions and were comparable to the standard nematicide carbofuran.