. Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . CO C•AU n< a QH so M PQ o< I-!O Oh < Ph FUNGI AFFECTING THE APPLE The Apple Scab Fusicladium dendriticum There is, jorobably, no fungous disease of fruits sofamiliar to the general public as the apple scab, or, as itis sometimes called, the black spot. This is due to a fungus which produces the well-known scabby spots upon thefruit, and also attacks the leavesand green shoots. It first ap-pears upon the leaves in theshape of smoky greenish spots,
. Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . CO C•AU n< a QH so M PQ o< I-!O Oh < Ph FUNGI AFFECTING THE APPLE The Apple Scab Fusicladium dendriticum There is, jorobably, no fungous disease of fruits sofamiliar to the general public as the apple scab, or, as itis sometimes called, the black spot. This is due to a fungus which produces the well-known scabby spots upon thefruit, and also attacks the leavesand green shoots. It first ap-pears upon the leaves in theshape of smoky greenish spots,more or less circular in gradually enlarge, andfrequently several of them runtogether, so as to form goodsized blotches; as they growolder their color darkens, finallybecoming almost black. Theupper surface of the leaf is usu-ally affected. Sometimes the fungus de-ON A LEAF. velops SO rapidly on the expand- ing leaves in early spring as to blight them, dwarfingand killing the younger foliage. An instance of this,observed by Professor L. II. Bailey, is illustrated in 27. FIG. 11. APPLE SCAB SPOTS 28 rUXGI AXD rUXGICIDES Plate 11, which represents the size of dwarfed leaves latein July, as compared with a full-grown one. In suchseasoDs the newly formed fruit is also attacked by thefungus, which shrivels the young apples and causesthem to fall off. Occasionally an entire crop is thusdestroyed. The spores, or reproductive bodies of the fungus,are produced in immense numbers on the blackenedspots on the leaf and fruit, forming most abundantly dur-
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpathoge, bookyear1896
