Production of alternaria Cassiae inoculum

Abstract

In order to adjust the methodology of inoculum production, an isolate of the fungus Alternaria cassiae, selected as a biological control agent for sicklepod (Senna obtusifolia) was studied under different culture media and mycelial growth conditions. Homemade V-8 juice medium without CaCO₃ addition, incubation on 200-250 mL of medium (around 50% of the flask volume) with agitation at 250 rpm during 48 hours, followed by mycelial mass growth in continuous dark were appropriate conditions for a large scale production of inoculum. The sporulation was aided by incubation of the mycelial mass at 25^oC. The use of 300 mL of mycelial mass per pan (29.9 by 44.5 by 5.0 cm ) to induce the sporulation provided rapid dryness and ensured the conidium integrity, indicated by higher infectivity of the inoculum.