Project Directorate of Biological Control (ICAR), P.B. No. 2491, H.A. Farm Post, Hebbal, Bangalore 560024, Karnataka, India.
Effect of post application factor (pH) was tested on the survival of indigenous isolates of Steinernema carpocapsae PDBC EN 11 and Heterorhabditis indica PDBC EN 13.3. Survival of infective juveniles was tested at pH 5 levels varying from 2–9. Maximum survival for H. indica was obtained at pH 5 and for S. carpocapsae at 7 and least at pH 2 and 3, respectively. S. carpocapsae tolerated a broader range of pH (4–9) than H. indica whose survival was affected from 2–3 and 8–9 showing least survival at extremes of acidity and alkalinity. Infectivity and progeny production of exposed nematodes were recorded at varying intervals. Infectivity of IJs of both the nematodes were not affected by varying pH levels except at 2 and 3. Progeny production was found at par with control for both the nematodes tested.
EPN, Steinernema carpocapsae, Heterorhabditis indica, pH
