ISOLATION AND CHARACTERIZATION OF ENTOMOPATHOGENIC ...

The maximum population of germination was recorded with 75 per cent conidia + 25
per cent sunflower at all storage temperature i.e. 38.00 per cent (room temperature), 41.33
per cent (earthern pot), 85.88 per cent (refrigerated), 93.73 (deep freezer) (Table 31).
However, other carrier material failed to differ from this treatment in case of refrigerated and
deep freezer. On the other hand, 50 per cent conidia + 50 per cent wheat flour supported
least germination (19.00 and 22.90 per cent at room temperature and earthern pot storage)
temperature respectively. There was no significant variation in the percentage germination
between the different oils and wettable powder carrier material under refrigerated and deep
freezer storage temperature.
4.8.2 Survival ability of Verticillium lecanii (Vl1)
20 DAS
After 20 days of storage at room temperature and earthern pot, maximum
germination was recorded with the formulation having 75 per cent conidia + 25 per cent
sunflower (95.90%) which was on par with 75 per cent conidia + 25 per cent groundnut
(96.15%). On the other hand, maximum percentage inhibition was recorded with 50 per cent
conidia + 50 per cent wheat flour (86.40%) and 50 per cent conidia + 50 per cent mustard oil
(86.32%) (Table 32).
In earthern pot storage temperature, maximum viability was found in oil formulation
i.e. 75 per cent conidia + 25 per cent sunflower and 75 per cent conidia + 25 per cent
groundnut with per cent germination of 96.33 per cent and 96.49 respectively, which failed to
differ from each other. The next best carrier material was 50 per cent conidia + 50 per cent
sunflower oil (95.06%) and followed by 50 per cent conidia + 50 per cent groundnut oil
(74.17%) and 75 per cent conidia + 25 per cent mustard oil (93.26%). The effect was nonsignificant
under refrigerated and deep freezer storage temperature.
45 DAS
In general, all the oil formulation carrier material had more viability than wettable
powder carrier material. After 45 day of storage, the conidial population of V. lecanii was
reduced to more than 15 per cent in all the carrier materials. At room temperature, maximum
germination of 72.76 per cent was observed with 75 per cent conidia + 25 per cent sunflower
oil followed by 50 per cent conidia + 50 per cent groundnut (60.51%) and least germination
was observed with 50 per cent conidia + 50 per cent wheat flour formulated carrier material
(50.74%) (Table 33). Similar to room temperature, 75 per cent conidia + 25 per cent
sunflower oil showed maximum viability (81.15%) under earthern pot temperature followed by
75 per cent conidia + 25 per cent groundnut (76.32%), 50 per cent conidia + 50 per cent
groundnut (69.98%) and 75 per cent conidia + 25 per cent sorghum flour (65.77%) (Table 33).
Under refrigerated storage 75 per cent conidia + 25 per cent groundnut oil had
maximum per cent germination (93.73), whereas under deep-freezer 75 per cent conidia + 25
per cent groundnut oil and 75 per cent conidia + 25 per cent sunflower oil were on par with
each other showing maximum per cent germination.
75 DAS
After 75 days of storage conidial population declined at both room temperature and
earthern pot. The trend in reduction of conidial viability remained same at 75 days as in 45
days of storage, under room temperature, whereas in the earthern pot storage 75 per cent
conidia + 25 per cent groundnut oil took the upper hand lagging behind 75 per cent conidia +
25 per cent sunflower oil and 50 per cent conidia + 50 per cent sunflower oil. However,
maximum reduction of population was recorded with 50 per cent conidia + 50 per cent wheat
flour formulated carrier material (Table 34).