. Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . the such pears, photographed by Dr. II. H. Lamson,are represented in Plate V. This disease is especially destructive to young peartrees in the nursery, and the defoliation caused by itquite generally prevents successful budding, unless pre-ventive treatment is given. A good general account ofthe fungus occurs in the 1888 report of the Departmentof Agriculture. The little black dots in the centers of the spots con-sist of the fruit of the fun
. Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . the such pears, photographed by Dr. II. H. Lamson,are represented in Plate V. This disease is especially destructive to young peartrees in the nursery, and the defoliation caused by itquite generally prevents successful budding, unless pre-ventive treatment is given. A good general account ofthe fungus occurs in the 1888 report of the Departmentof Agriculture. The little black dots in the centers of the spots con-sist of the fruit of the fungus. If a vertical section bemade of one of these and it be placed under the micro-scope, it will be seen that the pecu-liar two- to six-celled spores shown inFig. 21 are borne upon short stalkscoming from the mycelium in theleaf cells. These spores germinateunder favorable conditions, sendingout a tube which burrows its wayinto the tissues of the leaf, and startsthe fungus again. These spores arethe conidia, or summer spores. Otherspores—the so-called winter spores—are said, by some botanists, to be found among thefallen FIG. 22. PEAR LEAF-BLIGHT •iJ: FUXGI AXD FUXGICIDES Treatment.—Spray with the aramoniacal solutionof carbonate of copper as soon as leaves begin to unfold,and repeat application two or three times at intervals oftwo weeks; or the dilute Bordeaux mixture ma}^ beused, spraying in the same manner as recommended forapple scab. The effect of treatment with the Bordeauxmixture, as shown in one of Mr. Galloways experiments,is illustrated in Plate IV. Discontinue the treatmentbefore the fruit is half grown. The Pear Blight Micrococcus amylovorus The literature of American horticulture during thepresent century contains frequent references to the per-plexing malady called pear blight. Until recently therewere innumerable theories as to the cause and cure ofthe disease; but now, thanks to the investigations ofProfessors Burrill and Art
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpathoge, bookyear1896
