PT - JOURNAL ARTICLE AU - Alex L. Shigo AU - Richard Campana TI - Discolored and Decayed Wood Associated with Injection Wounds in American Elm AID - 10.48044/jauf.1977.060 DP - 1977 Dec 01 TA - Arboriculture & Urban Forestry (AUF) PG - 230--235 VI - 3 IP - 12 4099 - http://auf.isa-arbor.com/content/3/12/230.short 4100 - http://auf.isa-arbor.com/content/3/12/230.full SO - JOA1977 Dec 01; 3 AB - Dissection of 80 large American elm trees with a chainsaw revealed discolored and decayed wood associated with holes drilled for injections to control Dutch elm disease. Discolored wood was associated with every injection wound; injection wounds made in several successive years caused severe internal injuries. Until less injurious injection methods are developed, we suggest that injection holes be as small, shallow, clean-edged, and few as possible. Later injection sites should be at least 46 cm (18 in) above and not directly over older ones. If possible, drilling should be avoided at budbreak and in the valleys of fluted roots.