A Study of the Environmental Conditions Influencing the Development of Stem Rust in the Absence of an Alternate Host. III. Further Studies of the Viability of Urediniospores of Puccinia graminis tritici
Date of this Version
Peltier, George L. (1925). A study of the environmental conditions influencing the development of stem rust in the absence of an alternate host. III. Further studies of the viability of urediniospores of Puccinia graminis tritici (Research Bulletin: Bulletin of the Agricultural Experiment Station of Nebraska No. 34)
1. The influence of relative humidity and temperature on the viability of the urediniospores of two Physiologic Forms of Puccinia graminis tritici has been determined. 2. The same general relation between the viability of the urediniospores and the relative humidity and temperature was found, namely, that the lower the temperature the longer the spores retained their viability at all relative humidities, while at any stated temperature the spores were viable the longest at the medium humidities. 3. Urediniospores of Physiologic Form XXI held at 49.0 per cent relative humidity and maintained at a temperature of 5° C. when tested for germination at the end of 1 year yielded 30 per cent germination and produced a heavy infection on 2 out of 12 plants. 4. The application of this method for the storing of rust material for long periods is discussed.