Utilization of Non Edible Oil Seed Cakes as Substrate for Growth of Paecilomyces lilacinus and as Biopesticide Against Termites

Abstract

Oil seed cakes are the by-products obtained after mechanical extraction from the seeds. They are of two types edible and non-edible. Edible oil seed cakes have a high nutritional value with protein content ranging from 15 to 50 % and are mainly used as animal feeds. On the other hand the non-edible oil cakes such as Azadirachta indica (neem), Jatropha curcas (jatropha), Madhuca indica (mahua) and Pongamia pinnata (karanja) inspite of having high nutrient content cannot be used as animal feed due to the presence of toxic components in them. However, the toxicity of these cakes can be exploited by using them as biopesticides. Further non edible oil cakes can also be used as low cost substrates for the growth of the fungus Paecilomyces playing an important role in controlling nematodes. Therefore, the present paper focuses on the use of oil seed cakes as a substrate for the growth of fungus Paecilomyces and as biopesticide against termite. The crude active components responsible for the toxicity for each oil seed cake were extracted and the lab level bioassays were done against termite. Karanja cake based agar medium at C:N ratio 40:1 and pH 7 produced maximum radial growth and spore count per petri dish which were at par with commercial Czapeck-Dox agar media. The aqueous and methanolic extracts and the crude active components from all the cakes showed potent termite mortality.