Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . oval in shape, and have a faintpurplish tinge; they are easily detached, and wafted orwashed from plant to plant by wind or water. Underfavorable conditions they quickly germinate, enteringthe tissues through the breathing pores by means of ashort germ-tube. Thus the fungus may spread these conidia, or summer spores, the fungusdevelops certain winter spores, called oospores, bymeans of which it passes the winter. These are pro-duced within t
Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . oval in shape, and have a faintpurplish tinge; they are easily detached, and wafted orwashed from plant to plant by wind or water. Underfavorable conditions they quickly germinate, enteringthe tissues through the breathing pores by means of ashort germ-tube. Thus the fungus may spread these conidia, or summer spores, the fungusdevelops certain winter spores, called oospores, bymeans of which it passes the winter. These are pro-duced within the tissues, of the host-plant, and carry 150 FIG. G5. ONIONLKAF AFFECTEDWITH MILDEW. THE OXIOX SMUT 151 the fungus oyer from season to season. They have athicker wall than the conidia, and are spherical ratherthan oval. Treatment.—The destruction, by fire, of all refusetops in which the resting spores may pass the winter, isone of the most important remedial measures. Suchtops should never be turned under unless the ground isto be used for some other croj) the following of cro-ps will probable the most success-. FIG. GG. DEVELOPMENT OF SPOKES. MAGNIFIED. ful general remedy. Where the nse of fungicides ispracticable these, no doubt, can be employed to goodadvantage. Literature.—Professor William Trelease publishedan excellent account of the onion mildew, in 1883, inthe first report of the Wisconsin Experiment Thaxter also has a good discussion of it in the reportof the Connecticut Station for 1889 (pp. 155-158), and 152 FUXGI A^D FUNGICIDES Professor Dudley a notice of it in Bulletin 15 of theCornell Station. The Onion Smut Urocystis cepulce The smut of onions has been known to occur inAmerica for about thirt}- years, although it was not defi-nitely named and described by botanists until 1877. It iswidely distributed in the United States east of the Mis-sissippi river, and appears to be especially destructive inthe onion-growing regions of Con
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpathoge, bookyear1896
