Effect of storage temperature on viability of Pasteuria penetrans spores infecting Heterodera cajani

The effect of different storage temperatures (15, 30 & 50°C) for a period of one, two and three months on spore adherence and viability of Pasteuria penetrans spores infecting Heterodera cajani was investigated. The spore adherence declined significantly at 15°C with no significant reduction in spore viability. At 30°C no significant decline in spore adherence or viability was observed but at 50°C a significant reduction both in spore adherence andviability was observed. The percentage infected cysts formed were 68.42,66.66 & 50 at 15°C, 66,75 & 56.5 at 30°C and 6.25, 8.8 & 4.0 at 50°C after exposure periods of one, two andthree months respectively.