| Autor: |
Thurston, H., Knutson, Kenneth, Eide, Carl |
| Zdroj: |
American Potato Journal; 1958, Vol. 35 Issue 2, p397-406, 10p |
| Abstrakt: |
During four seasons, late blight on the foliage of potato plants spread to nearby plants during periods described by Wallin and his coworkers as 'favorable,' i.e. 10 or more hours of relative humidity above 90 per cent and temperatures between 60° and 77° F. Over 56 per cent of the favorable periods in the 4 years occurred on days with rain. In most instances Hyre's 'moving graph' system of relating weather to blight would have indicated periods of spread accurately. The rate of spread of blight differed in plots on peat and silt loam soil, but the differences were not definitely associated with differences in temperature and humidity recorded by the hygrothermographs. It appears that in regions where primary inoculum occurs sporadically, the prediction of blight development by the use of hygrothermographs should be supplemented by surveys to determine if centers of infection exist in the fields. In a single comparison, race 0 of Phytophthora infestans spread more rapidly than race 1 in a similar plot. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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