Effect of Temperature, Relative Humidity and Different Sugar Solution on Uredospore Germination of Sugarcane Rust Caused by Puccinia melanocephala H and P. Syd.

Sugarcane rust caused by Puccinia melanocephala H. and P. Syd. is one of the major constraints in the production of sugarcane. Temperature and sugar contain in the leaves are important factors for all metabolic activities of the fungus. After temperature, relative humidity (RH) is crucial factor for infection, reproduction and survival of fungus. Experiment were carried out under in vitro, with respect to spore germination of P. melanocephala. Experimental results revealed that, uredospores germinate at temperature range of 5°C to 35°C. The maximum (87.37%) spore germination of P. melanocephala was observed at 25°C after 24 hrs of incubation and at 85 per RH uredospore germination was 83.8 per cent, spore germination was least (38.6%) at 65 per cent RH. The maximum uredospore germination of 75.30 per cent was recorded in two per cent sucrose solution. Among the sugar solutions, least uredospore germination (50.45%) was observed with dextrose at 0.5 per cent.