Effects on Maples of Prolonged Exposure by Artificial Girdling Roots
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Francis W. Holmes
Abstract: Artificial girdling of silver, sugar, Norway, Schwedler Norway, Crimson King Norway, and red maples was achieved by applying pressure of the trees' own growth against trunk expansion at ground level. Single angle irons plus a cable (Type I) were applied in 1966, and two parallel angle irons, bolted at their ends (Type II) were applied in 1967. Where girdles were applied, trunks were 6 to 8 cm (2.5 to 3 in.) in diameter. Next to each treated tree was an untreated one. Type I was associated with early fall color on all silver maples the first summer. The next year those trees died, completely girdled. Red and sugar maples slowly filled the entire Type I girdle, and all died after 7-8 years, but Norway maples engulfed the Type I devices and are alive as of 1983. In Type II, bolts were 30 cm apart; silver and Norway maple trunks filled these gaps after 16 years. The angle irons remained straight or bent only slightly. Tree bases with Type II treatment were greatly distorted but no foliar symptoms appeared. Trunk diameters and heights were equivalent to those of check trees. Tree vigor and growth were not affected until all or nearly all the circumference was girdled.
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https://doi.org/10.48044/jauf.1984.007
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