Date of this Version
Peltier, George L. (1922) A study of the environmental conditions influencing the development of stem rust in the absence of an alternate host. I. The viability of the urediniospores of Puccinia graminis tritici form III (Research Bulletin: Bulletin of the Agricultural Experiment Station of Nebraska No. 22)
No exact data are at hand regarding the influence of temperature and relative humidity on the viability of the urediniospores of stem rust under controlled conditions. 1. The influence of relative humidity on the viability of the urediniospores of Puccinia graminis tritici Form III is very pronounced and closely associated with temperature. 2. At high relative humidities, depending somewhat on the temperature, the percentage of germination is low and the period over which the spores are viable is very short. 3. The same relation exists at the low relative humidities except that it is not so pronounced and is more variable. 4. The highest percentage of germination and the longest viable period of the spores occur at the medium relative humidities. High temperatures lower the percentage of germination and shorten the viable period while at low temperatures the opposite occurs, at the medium relative humidities.