. The cultivated evergreens; a handbook of the coniferous and most important broad-leaved evergreens planted for ornament in the United States and Canada. Evergreens; Conifers. INSECTS, DISEASES, AND INJURIES 155 Cronartium rihicola, Fischer, which is a most formidable enemy of the white pines (i. e., those in which the needles are in fascicles of five). Without doubt all five-needled pines are liable to be at- tacked if exposed to the pathogen. The fungus was first found in North Amer- ica at Geneva, New York, in 1906, but it is probable that it was present for some years prior to that date.
. The cultivated evergreens; a handbook of the coniferous and most important broad-leaved evergreens planted for ornament in the United States and Canada. Evergreens; Conifers. INSECTS, DISEASES, AND INJURIES 155 Cronartium rihicola, Fischer, which is a most formidable enemy of the white pines (i. e., those in which the needles are in fascicles of five). Without doubt all five-needled pines are liable to be at- tacked if exposed to the pathogen. The fungus was first found in North Amer- ica at Geneva, New York, in 1906, but it is probable that it was present for some years prior to that date. Until the summer of 1921 it was confined to New England, New York, and the Lake States where it has caused very serious losses on the eastern white pine (Pinus Strobus). In spite of all efforts to prevent its spread to the valuable stands of western white pine (P. monticola) and sugar pine (P. Lamhertiana) in the Western States, the disease was discovered in western British Columbia and in northwestern Washington in 1921. In addition to the five-needled pines, the fungus also attacks wild and culti- vated species of currant and gooseberry. Although all species of Ribes are more or less susceptible to attack, the culti- vated black currant (Ribes nigrum) takes the disease most severely. The currant and gooseberry are known as "alternate hosts," in- asmuch as the fungus must pass a portion of its life upon one of these before fresh pines can become infected. Pines of all ages are susceptible to the disease. The fungus gains entrance at the bases of leaf-fascicles or directly through. White pine with bHster- 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 Bailey, L. H. (Liberty Hyde), 1858-1954. New York, The Macmillan company; London, Macmillan & co. , ltd.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectconifer, bookyear1923
