Viability of Pasteuria penetrans parasitising Meloidogyne incognita under different conditions

Pasteuria penetrans infested soil exposed to 19 and 28°C and natural field conditions over a period of 12 months was evaluated for spore attachment on the juveniles of Meloidogyne incognita. Maximum reduction in the adherence of spores was recorded in the soils kept under natural conditions. In this treatment the decline in spore attachment was more during summer months than winter months. The soils stored at 19 and 28°C also showed a reduction in the spore viability. At both these temperatures reduction in spore attachment increased with the increase in the storage period. The overall reduction in per cent spore encumbrance on juveniles of M. incognita after a period of 12 months was 73.8, 67.9 and 61.7% in the soils kept under natural conditions and at 28 and 19°C respectively. The storage period was also found to affect the per cent larval infection by the bacterium and after a period of 12 months under natural conditions only 20% larvae showed infection by the bacterium while it was 47–50% in case of soils stored under incubated conditions.