. Diseases of economic plants. Plant diseases. Trees and Timber 377 prevent further inroads by fungi already established in them. The real value of surgical treatments is somewhat problematical. The practice is of compar- atively recent popularity, and a long interval of time is necessary to determine the amount of benefit. The procedure is as fol- lows: First, all decayed, diseased, or injured wood or bark must be removed, either by severing a limb entire or by cutting out a cavity, in which case a mallet, sharp gouges, chisels, and a knife are needed. To reach all of the diseased wood it is
. Diseases of economic plants. Plant diseases. Trees and Timber 377 prevent further inroads by fungi already established in them. The real value of surgical treatments is somewhat problematical. The practice is of compar- atively recent popularity, and a long interval of time is necessary to determine the amount of benefit. The procedure is as fol- lows: First, all decayed, diseased, or injured wood or bark must be removed, either by severing a limb entire or by cutting out a cavity, in which case a mallet, sharp gouges, chisels, and a knife are needed. To reach all of the diseased wood it is usually necessary to en- large the opening and fre- quently to make one or more holes above or be- low the main opening, or, what is perhaps better, to cut a narrow opening of the required length. The excavation should be en- larged in all directions until only sound, unin- fected wood is left. The bottom of the cavity should be so shaped as to provide drainage. The edges of the cavity should. Fig. 198. — Detailed view of exca- vated and bolted cavities. Above cross-section of a young tree trunk showing how the new wood and bark grow into an unfilled cavity from the margin. (The line on the wood indicates the amount of ex- cavating that would be needed be- fore filling the cavity.) 3. — Cross- section of a tree trunk showing the manner of using two single- headed bolts to brace a cavity. After 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 Stevens, Frank Lincoln, 1871-1934; Hall, John Galentine, 1870-. New York, Macmillan
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Keywords: ., bookauthorstevensf, bookcentury1900, bookdecade1920, bookyear1921
