The control of brachystegia boehmii trees with stem injections of various tordon formulations
Killilea, D.M.; Mcneill, L.
Zimbabwe Journal of Agricultural Research 20(1): 71-75
Tordon 101 (a 1:4 water soluble mixture of picloram and 2,4-D), Tordon 225 (a 1:1 water soluble mixture of picloram and 2,4,5-T) and Tordon 155 (a 1:4 oil soluble mixture of picloram and 2,4,5-T) were applied to B. boehmii trees at different times of the year. Five application rates were tested for each of the arboricides. Chemicals were placed either into a series of cuts made through the bark at the base of the tree trunk or into a frill encircling the stem base. For the sample application rate of picloram, Tordon 101, Tordon 225 and Tordon 155 tended to be equally effective. Treatment of trees in the main growing season, Nov. to April, was more effective than treatment of trees in July. Tree response was similar for both methods of application. A rate of 0.007 g acid equivalent picloram per cm of stem circumference was sufficient to kill 80% of trees under most circumstances.