. Diseases of economic plants. Plant diseases. Tropical Fruits 143 are at first yellowish, b\it as the disease advances they become almost black, and finally crack open. Ammoniacal copper carbonate or Bordeaux mixture will prevent scab. Anthracnose, wither-tip {Colletotrichum gloeosporioides Penz.). — In this disease the leaf spots are circular in out- line, yellowish in color, and bear the small dark filaments and spores of the causal fungus. Terminal twigs shed their leaves and die. The disease also occurs upon the fruit of various citrus trees. Rolfs noted its attack upon the lemon, where i
. Diseases of economic plants. Plant diseases. Tropical Fruits 143 are at first yellowish, b\it as the disease advances they become almost black, and finally crack open. Ammoniacal copper carbonate or Bordeaux mixture will prevent scab. Anthracnose, wither-tip {Colletotrichum gloeosporioides Penz.). — In this disease the leaf spots are circular in out- line, yellowish in color, and bear the small dark filaments and spores of the causal fungus. Terminal twigs shed their leaves and die. The disease also occurs upon the fruit of various citrus trees. Rolfs noted its attack upon the lemon, where it caused the fruit to fall prematurely, and Hume reports that it may occur upon the pomelo either before or after the fruit is picked. The brownish spots enlarge with age and become dirty black in color. The fun- gus invades the interior of the fruit as well as the rind. In all cases the diseased parts should be cut out, care being taken to cut far enough back to remove all injured" parts; also affected fruits should be removed and destroyed. Spray- ing with Bordeaux mixture controls the disease upon the fruit. Root-rot {PMjtophthora terrestria Sherb.). — The first symp- toms are abundant exudations of gum upon the trunk of the tree; at the same time the bark develops brownish patches, which are thrown off, followed by other patches. The tree appears to lack nutrition, the leaves becoming yellow, scanty, and small. Though the trees bear considerable fruit, the amount of damage in Florida was estunated in 1896 to be. Fig. 75. — Orange leaves showing spots caused by anthracnose. Af- ter Hume,. 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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Keywords: ., bookcentury1900, bookdecade1920, bookpublishernewyo, bookyear1921
