Distribution of Dye in Elms After Trunk or Root Injection

Abstract

Acid fuchsin dye, when injected under 1.1 kg/cm 2 pressure through hollow, tapered spiles that had been driven into 1.5 cm diameter holes drilled 4 cm deep into elm tree trunks, came up in all the xylem vessel layers intersected by the holes except in the current year’s layer of the xylem. When the same dye was injected into comparable trees through the severed ends of roots, however, nearly all of it came up in the xylem vessel layer of the current year. This result may help to account for variable success in controlling Dutch elm disease by trunk injection of fungicides.