Effect of Physiological Factors on Uredospores of Different Isolates of Puccinia arachidis Speg. Causing Rust Disease in Groundnut

Groundnut rust caused by Puccinia arachidis Speg., is one of the important disease fungal disease which causes loss up to 29–42 per cent. The diseases influenced by physiological factors like temperature and relative humidity (RH). The experiments were carried out in vitro, with respect to uredospore germination of Puccinia arachidis. The result revealed that maximum spore germination was occurred at 25°C in 24 hr in all the isolates of fungus. The isolates, PaMAN showed maximum spore germination (90.00%) and PaHIR showed minimum germination (65.00%) in 25°C. The maximum spore germination was observed at 90 per cent RH in all the isolates and the isolates PaHUB showed maximum spore germination (93.00%) and minimum (82.67%) was recorded in PaMOR.