Manifestation and dispersal of entomopathogenic nematodes in orchard ecosystem with regards to soil characters in three different zones of Chhattisgarh state

Abstract

Entomopathogenic nematodes (EPNs) are round worms from the genera Steinernematid and Heterorhabditid. They are ubiquitous in nature. Survey results of the present study show that 7 samples out of 800 collected samples (0.87%), were positive for EPN which were obtained from silty loam and loamy sand soil. This is an extensive first of its kind study on EPN survey throughout the state of Chhattisgarh. The EPN were recovered from 5 of the 24 surveyed districts namely Baloda Bazar (Ber crop), Mahasamund (Mango crop), Raipur (Sapota crop, Papaya and guava), Bijapur (Mango crop), Sukma (Mango crop). The organic matter estimate from EPN recovered soils were found to be in the range of 0.56- 1.06 % with pH of slight acidic to neutral (5.6-7.1). Water holding capacity of EPNs isolated soil was 32.05 - 38.87 % and bulk density was 0.96 – 1.27 g/cm3 with moisture percentage of 4.26- 24 %. The present study shows that nematodes can be found in low moisture soil as well as high moisture soils. The results of molecular identification reveals that isolated EPN samples were identified as Heterorhabditis indica. EPNs are being investigated primarily for biocontrol purposes. There are many exotic EPN which had conflicting results in many field testing situations, most likely due to their low adaption to local agro-climatic conditions. Henceforth our quest was to look for an indigenous variety of EPN which can be used as a novel bio pesticide, our work mainly focuses on identification of local EPN strains from Chhattisgarh state which can be further used in Integrated Pest Management programme.