. Fungous diseases of plants : with chapters on physiology, culture methods and technique . Fungi in agriculture. 284 FUNGOUS DISEASES OF PLANTS The fungus. The mycelium penetrates the bark and later the wood beneath to a considerable extent. The course of the fungus through the bark and wood is very largely through the paren- chymatous and medullary cells. From these, however, it infests neighboring tissues, especially the xylem vessels. The stromata and fruit bodies are developed from the latter part of the summer into the autumn and winter. From the upper surface of the stroma a mat of coni
. Fungous diseases of plants : with chapters on physiology, culture methods and technique . Fungi in agriculture. 284 FUNGOUS DISEASES OF PLANTS The fungus. The mycelium penetrates the bark and later the wood beneath to a considerable extent. The course of the fungus through the bark and wood is very largely through the paren- chymatous and medullary cells. From these, however, it infests neighboring tissues, especially the xylem vessels. The stromata and fruit bodies are developed from the latter part of the summer into the autumn and winter. From the upper surface of the stroma a mat of conidial hyphse arises. These break through the epidermis and underlying fun- gous tissue. The conidia are simple, hyaline spores which apparently do not readily ger- minate. Later in the season the underlying stromatic tis- sue which is now cup-shaped shows the development of flask-shaped perithecia sunken in that portion of the stroma which is made up chiefly of fungous tissue. Bordering the stroma a black line of more abundant fungous tissue is also evident. The body of the perithecium is elliptical or ovate at maturity, and it is com- pletely filled with long-cylin- drical asci about 160 X 13/4. The asci are thick-walled with terminal pore, and contain at maturity eight more or less spher- ical, brown spores. The latter often measure 13 x 10/i, and a clear space along one side indicates the line of rupture during germina- tion. Twin germ tubes are invariably developed. Control. Observations on the progress of this disease would seem to indicate that this fungus gains entrance through wounds, and prevention consists in avoiding as far as possible the im- proper injuries due to careless methods of pruning, cultivation, and harvesting. Moreover, the cankered areas on limbs should be pruned out and destroyed when flg. 126. nummularia discreta : t Blister Canker Fungus a, stroma; b: perithecium ; c, ascus. Please note that these images are extracted from scanned page images
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Keywords: ., bookauthorduggarbe, bookcentury1900, bookdecade1900, bookyear1909
