THE MOVEMENT OF INJECTED DYE SOLUTIONS IN HEALTHY AND NEEDLE-BLIGHTED WHITE PINE TREES

Abstract

The movement of dye solutions in stems of white pine trees, Pinus strobus L., was studied by injection methods. Of several solutions used, a dilute aqueous solution of acid fuchsin was the best indicator of water absorption and movement in the tree. One-hole injections permitted a better assessment of the movement of solutions in the tree than girdle injections. Solution absorption in white pine through a girdle injection locus was observed to average about one liter per hour at the start of the injection period and to diminish with time. Increasing amounts of solution were absorbed and advanced higher in the tree with increasing numbers of daylight hours. Solution absorption and movement in the tree were depressed during night hours. Height of movement of the solution in the tree was unaffected by the size of the injection incision. Exposing the outer sapwood by cutting a "window" through the bark permitted the observation of the actual movement of a dye solution in a living tree.The effect of needle blight on solution movements was investigated by simultaneous injections of paired healthy and diseased pine trees. Smaller quantities of solution were taken in by diseased trees, per unit time. The rates of solution uptake, however, were similar in needle-blighted and healthy trees.