Killing Eucalyptus grandis cut stumps after multiple coppice rotations in the KwaZulu-Natal midlands, South Africa

Abstract

The repeated regeneration of Eucalyptus grandis through the managementofcoppice shoots results inlarge multi-stemmed stumpsthat are difficult to kill To test the most effective mannerinwhichthese stumps could be killed, a trial wasinitiated at felling on a fourth rotation stand of E. grandis stumpsinthe KwaZulu-Natal Midlands. Triclopyr (amine salt, 360 g P), triclopyr (butoxy ethyl ester, 480 g 1.1 ) , imazypyr (100 g 1.1 ) , metsulfuron-methyl (600 g kg') and a combination oftriclopyr (butoxy ethyl ester, 480 g 1'1) + glyphosate (isopropylamine salt, 192 g1-1 ) were applied to a basal frill, the cut surface, or the foliage of coppice regrowth of E.grandis stumps. These treatments were compared to anuntreated control where the coppice regrowth was manually cut with an axe. Irrespective ofthe active ingredient, the use of herbicides proved to be more effective in preventing coppice regrowththanby manual control with an axe. The application ofherbicides to a basal frill killed 90 % of the stumps and required the least follow-up control.