. Diseases of economic plants. Plant diseases. 58 Diseases of Economic Plants infections usually occur about the time the trees are blossoming, and that serious damage may be caused by in- fections taking place for four or five weeks after the petals have fallen; that the first serious infections of apple blotch may take place three or four weeks after the petals have fallen, and that further infections, resulting in serious damage, may occur for a period of five or six weeks; that the first infections of bitter-rot may occur about the middle of June,. Fig, 28. — Unsprayed apple trees. A
. Diseases of economic plants. Plant diseases. 58 Diseases of Economic Plants infections usually occur about the time the trees are blossoming, and that serious damage may be caused by in- fections taking place for four or five weeks after the petals have fallen; that the first serious infections of apple blotch may take place three or four weeks after the petals have fallen, and that further infections, resulting in serious damage, may occur for a period of five or six weeks; that the first infections of bitter-rot may occur about the middle of June,. Fig, 28. — Unsprayed apple trees. After Scott and Rorer. the period of possible infection continuing throughout the season, the probability of infection being greatest in hot, wet weather. The choice of the fungicide and the decision as to when to spray are governed by several considerations. These include the local conditions, among which may be placed varietal susceptibihty to apple scab, and the probable local varietal susceptibility to other fungi, seasonal weather conditions, and varietal susceptibility to spray injury. Locality. — Apple scab, apple blotch, and bitter-rot are so. 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 Stevens, Frank Lincoln, 1871- [from old catalog]; Hall, John Galentine, 1870- [from old catalog] joint author. New York, The Macmillan company
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License: Licensed
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Keywords: ., bookcentury1900, bookdecade1920, bookpublishernewyo, bookyear1921
