Jacob Joseph Taubenhaus
Published: 2013-09
Total Pages: 84
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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 edition. Excerpt: ...are straight to curved, with both ends rounded. The conidiophores are short, the seta abundant, dark brown, simple, and mostly straight (fig. 40, e and f). Control. The disease is often introduced in the greenhouse with infected cuttings. Cuttings should therefore be secured from healthy plants. This disease attacks only the snapdragon. It should therefore be an easy matter to prevent its introduction indoors. If the disease makes its appearance, spraying with Bordeaux mixture should be resorted to. All diseased material should be destroyed by fire. Branch Blight Caused by Phoma poolensis Taub. Symptoms. The disease seems to be confined to the tender and growing shoots. It seldom affects the older and more woody stems. Affected parts wilt, and become discolored without showing any definite spotting. Later, however, numerous pycnidia appear on the dead parts. The Organism.--Stewart has proved by artificial inoculation that the causal organism is a parasite. The writer's investigation of this organism has confirmed the work of Stewart. In 1916 and 1917, a careful study of this disease was made, as it occurred in several greenhouse establishments in San Antonio, Stewart, F. C, New York (Geneva) Agr. Expt Sta. Bui. 179: 109-110, 1900. Texas. It was proved definitely that the organism is parasitic and that it was also apparently an undescribed species to which the name Phoma poolensis Taubenhaus was given. The pycnidia are minute, numerous, black, with distinct mouths (ostioles). The spores ooze out in a colorless gelatinous ropelike mass. They are small, elliptical, hyaline, and one celled. Control. The methods of control for this disease should be the same as those used for anthracnose. Blight Caused by Septoria antirrhini Desm. This disease...