Effect of Temperature Regimes on the Survival of Steinernema masoodi AMU EPN-1

The study was conducted to determine the survivability of Steinernema masoodi AMU EPN-1 at different temperatures in- vitro in cavity blocks and earthen tea cups and in-vivo in earthen pots kept in a guava orchard. The in vitro study was conducted by incubating 2500 infective juveniles of the nematode in distilled water in cavity blocks and in soil (100 g) in earthen tea cups in BOD incubators at 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50°C for 4, 6, 8 and 12 h. The nematode survival was almost 100% at 5–25°C temperature in distilled water or in soil. However, from 30°C onwards the survival decreased gradually and the mortality reached 100% at 50°C. The nematode survival in distilled water at 30, 35 and 40°C was 61–89%, 53–84% 39–59% at 4–12 hour duration respectively, and 33–45% at 45°C. The survival was 1–14% greater in the soil. The nematode survival was greatest in the pots placed under full shade and gained an increase of 54 to 61% during November-December in comparison to the initial population (September 2007). The nematode population declined by 10–96% during March to June and showed an increase in July to September. The minimum survival of nematode was recorded in June in comparison to the initial population under shaded and partially shaded environment.