. Bulletin. Natural history; Natural history. 488 Illinois Natural History Survey Bulletin while the intensity of its attack on fruit was only per cent. But in 1923 the epidemic was severe, prevalence then rising to 100 per cent, and intensity to per cent. In the following year, 192-1. there was no appreciable reduction in brown-rot prevalence. The index for that year stood at per cent., a reduction of only .06 per cent, from 1923; but the intensity of brown-rot attack on the fruit increased to per Fig. 26. Scale for estimating the intensity of spotting on cherry
. Bulletin. Natural history; Natural history. 488 Illinois Natural History Survey Bulletin while the intensity of its attack on fruit was only per cent. But in 1923 the epidemic was severe, prevalence then rising to 100 per cent, and intensity to per cent. In the following year, 192-1. there was no appreciable reduction in brown-rot prevalence. The index for that year stood at per cent., a reduction of only .06 per cent, from 1923; but the intensity of brown-rot attack on the fruit increased to per Fig. 26. Scale for estimating the intensity of spotting on cherry leaves In each example the area of the spots is expressed as a percentage of the area of the leaf. No effort is made in using this scale to distinguish between leaf-spots resulting from different causes. Though these three are the only years of the period covered by our survey for which we have representative data, they serve to indicate the importance of brown-rot as a cherry disease. With an average an-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natural History Survey Division. Urbana, State of Illinois, Dept. of Registration and Education, Natural History Survey Division
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Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
