Chemical control of coppicing shoots of brachystegia boehmii brachystegia spiciformis and julbernardia globiflora 3. cut stem applications of tordon 101 tordon 225 tordon 155 or 2 4 5 t
Heelas, B.V.; Killilea, D.M.; Mcneill, L.
Zimbabwe Journal of Agricultural Research 19(2): 191-203
1981
Accession: 004937426
In a series of experiments on the control of coppicing B. boehmii, B. spiciformis and J. globiflora trees, various arboricides were applied to freshly cut surfaces of stems cut near ground level. The water soluble formulations Tordon 101 (1:4 mixture of picloram and 2,4-D) and Tordon 225 (1:1 mixture of picloram and 2,4,5-T) were generally more effective than the oil soluble formulations Tordon 155 (1:4 mixture of picloram and 2,4,5-T) and KOP 250 (2,4,5-T). Arboricide effectiveness was on average increased 160 times by improved placement of the arboricide: cutting the plant back to expose the original stump or root and placing the arboricide into incisions made in the cambial region of the cut surface. The smallest amounts of arboricide required to achieve an 80% kill rate with application in June or July using the cambial placement method were established using probit transformation of the data. Expressed as g total acid equivalent (a.e.)/cm stem circumference these were: B. boehmii 0.0002 and 0.0003; B. spiciformis 0.0108 and 0.0053 and J. globiflora 0.0068 and 0.0030 g a.e. Tordon 101 and Tordon 225, respectively. Application of arboricide in March was generally more effective than application in June or Aug. Arboricide efficiency was also influenced by plant size, although the nature of the relationship was not simple.