Efficacy of nano bioformulation for the management of red spider mite Oligonychus coffeae

Abstract

The present investigation was conducted in the Department of Tea newlineHusbandry and Technology, Nano Lab of Department of Plant Pathology and field newlineexperiment were conducted in Experimental Garden for Plantation Crops (EGPC), newlineAssam Agricultural University (AAU), Jorhat, Assam during 2016-2020 to carry out the newlineexperiments to obtain nanoparticle and characterization. newlineThe nano particles were synthesized from Fusarium oxysporum, fish and newlinecrab and used as NP-1, NP-2 and NP-3 respectively. The nanoparticle used were newlinecharacterized by UV-VIS, Zeta Sizer, TEM and DLS. UV-VIS spectroscopy of chitosan newlinenanoparticles was carried out a range of wavelength of 314.00, 340.00, 348.50 nm 200- newline600 nm and results showed maximum absorption at critical wavelengths for a particular newlinenanoparticle respectively for F. oxysporum, fish and crab chitosan nanoparticles. Zeta newlinepotential values of the present nanoparticles were recorded positively charged with zeta newlinepotential of 3.85, 16.89 and 20.48 respectively for chitosan nanoparticles of F. newlineoxysporum, fish and crab. Similarly, TEM study showed the present nanoparticles were newlinesmooth surfaced with spherical in shape. On the other hand DLS study showed the size newlineof the nanoparticles as 105.6, 98.0, 285.0 nm respectively for F. oxysporum, fish, crab. newlineIn vitro evaluation of chitosan NPs synthesized from F. oxysporum, fish and crab in newlinecombination of M. anisopliae and V. lecanii against red spider mite was tested at newlinedifferent doses (5 ml/lit, 7 ml/lit and 10 ml/lit) at 100 ppm concentration. At first day newlineafter treatment highest per cent mortality recorded from M. anisopliae + NP-2 (38.55%) newlineat dose of 7 ml/lit. At third days of spray the highest per cent mortality was recorded newlinefrom M. anisopliae + NP-2 (65.42%) at 7 ml/lit .This was followed by M. anisopliae + newlineNP-2 (58.79%) and (58.05%) at 10 ml/lit and 5 ml/lit respectively. At fifth days after newlinetreatment M. anisopliae + NP-2 showed maximum mortality against O. coffeae (81.66%) newlineat 7ml/lit followed by M. anisolipae + NP-2 (79.76%) and (76.48%) at dose of ...