Quantification of viable spore load of oil based formulation of Beauveria bassiana Bals. (Vuill) delivered through different delivery equipments on onion and chilli

Abstract

Some of the main issues in the successful use of entomopathogenic fungi for pest control include the application, infectivity and persistence of their inoculum in the environment. In this connection, suspending entomopathogenic fungal conidia in oil frequently improves their environmental persistence and virulence against insects, compared to water suspensions. In microplot, the quantification of viable spore load (in terms of CFU per sq.cm leaf disc) of oil based formulation of Beauveria bassiana Bals. (Vuill) (Bb 112) delivered through different delivery equipments revealed that the CFU load was invariably higher in onion (fully opened 4th leaf) (fully opened 4th leaf) and top leaves of chilli plants sprayed with CDA sprayer (Controlled Droplet Applicator) (434.23 and 453.21 CFU cm-2) on the day of application. This was followed by Avenger ULV sprayer > Aspee Maruyama Engine Sprayer > Aspee Knapsack Hand Sprayer > Aspee Hitech Hand Sprayer > Aspee Battery Sprayer.