Effect of abiotic factors on spore attachment of Pasteuria penetrans to juveniles (J2) of Meloidogyne incognita

Experiments were carried out to study the effect of three important abiotic factors viz., temperature, moisture and pH on spore attachment of Pasteuria penetrans. Maximum adherence of spores within average of 25.0 spores/J2 was observed at 26°C in comparison to 9.68 and 13.38 spores/J2 at 23 and 29°C, respectively. Out of four moisture levels tested for spore attachment, nematode recovery and spore attachment were maximum at a moisture level of 50% (23.03) followed by 13:77, 9.06 and 3.95 at 75, 100 and 25 per cent moisture level respectively. The per cent encumberance at 50 per cent treatment was higher. However, lowest J2 was recovered (32.13%) from soil with 25% moisture content and highest recovey (55.80) at 75% moisture treatment. With regard to pH more spore attachment (28.84 spores/J2) was observed at 7.6 pH, which decreased to 11.91 and 8.31 spores/J2 in 6.4 and 5.2 pH, respectively.