Diseases of economic plants (1921) Diseases of economic plants diseasesofeconom01stev Year: 1921 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
Diseases of economic plants (1921) Diseases of economic plants diseasesofeconom01stev Year: 1921 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. â⢠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. ââ Cross- section of a tree trunk showing the manner of using two single- headed bolts to brace a cavit}'-. After Collins.
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