Fungous diseases of plants . stage is not believed to be important to continue thepropagation of the fungus. During the spring of 1902 the Scle-rotinia stage was found (Norton) quite commonly in the orchardsof Maryland, The apothecia were discovered arising from scle-rotia, which might be developed either within the tissues or on ASCOMYCETES 193 the surface of the mummied fruits. The fruits upon which thisstage appeared had been hghtly covered with sandy soil for atleast a year. In 1906 this stage was extremely common through-out the West. Conditions seemed to be most favorable for its de-velo
Fungous diseases of plants . stage is not believed to be important to continue thepropagation of the fungus. During the spring of 1902 the Scle-rotinia stage was found (Norton) quite commonly in the orchardsof Maryland, The apothecia were discovered arising from scle-rotia, which might be developed either within the tissues or on ASCOMYCETES 193 the surface of the mummied fruits. The fruits upon which thisstage appeared had been hghtly covered with sandy soil for atleast a year. In 1906 this stage was extremely common through-out the West. Conditions seemed to be most favorable for its de-velopment where the fruit had lain for eighteen months in littledepressions in the sod, and fairly well covered by grass stalk or stipe of the apothecium was from .5 to 3 cm. inlength, depending upon the distance of the mummy beneath thesoil. The stipe is dark brown and the slightly bell-shaped diskis a shade lighter. The latter is usually 5-8 mm. in diameter,though it may range from 2 to 15 mm. The general appearance. Fig. 73. Apothecia of Sclerotinia from Mummied Plums of the apothecia is shown in Fig. 73. The stipe consists of amedulla of elongated, intertwined, brown cells and a cortex ofshorter, darker ones, the latter being continued in a tissue pro-jecting beyond the hymenium. The asci are cylindrical-clavate,125-215 X 7-10 They arise from a dense layer of smallhyphse, differing from the general medullary hyphae merely in be-ing more closely intertwined (Fig. 72, c and d). The ascosporesare ellipsoidal and measure 10-15 x 5-8 They are obliquelyuniseriate, or subseriate. The paraphyses are characteristic ofmany Pezizaceae, — hyaline, septate, simple or branched, filiform,and slightly swollen at the tips. 1 Reade, J. M. Preliminary Notes on Some Species of Sclerotinia. AnnalesMycologici 6 : 109-116. 190S. 194 FUNGOUS DISEASES OF PLANTS Control. Preventive treatment should be begun in late winteror very early spring and must consider two possible sourcesof
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