. Diseases of truck crops / Ralph E. Smith. Plant diseases; Plant parasites; Vegetables; Agricultural pests. 32 California Agriculturad Extension Service [CiR. 119 The plants are stunted, the central leafstalks being shortened and the outer ones assuming a horizontal position. The disease is most prevalent during the summer months and is spread by aphids from plant to plant. No wild host plants are known, but carrots and celeriac are susceptible. Several other mosaiclike diseases of celery are distinguished in Cali-. Fig. 16.—Western celery mosaic. fonia, including those called "calico,&q
. Diseases of truck crops / Ralph E. Smith. Plant diseases; Plant parasites; Vegetables; Agricultural pests. 32 California Agriculturad Extension Service [CiR. 119 The plants are stunted, the central leafstalks being shortened and the outer ones assuming a horizontal position. The disease is most prevalent during the summer months and is spread by aphids from plant to plant. No wild host plants are known, but carrots and celeriac are susceptible. Several other mosaiclike diseases of celery are distinguished in Cali-. Fig. 16.—Western celery mosaic. fonia, including those called "calico," "yellow spot," and "ring spot," as well as aster yellows (p. 29) and spotted wilt (p. 33). These are much less important than western celery mosaic, which is a serious disease in most celery-growing districts of the state. Spraying to control aphids may help to prevent the spread of mosaic. For this purpose, nicotine may be added to the sprays used for blight (p. 30). In one part of the state, the control of mosaic has been attempted by the legal establishment of a "celery-free period" of 3 months, during which time no celery plants are allowed to exist in the district.'" Such i<»See: Milbrath, D. G., and Harold J. Eyan. A method of control of western celery mosaic. California State Dept. Agr. Bui. 27:290-95. 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 Smith, Ralph E. (Ralph Eliot), 1874-1953. Berkeley, Calif. : College of Agriculture, Univ. of Calif.
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