Leaf growth of brigalow (Acacia harpophylla) suckers in relation to seasonal conditions

Abstract

Leaf growth of brigalow suckers commenced after winter in 1962 when the mean minimum temperature rose to over 50°F. The duration of this growth and subsequent summer growth were related to prevailing soil moisture conditions. The brigalow grew until the first frost in 1963, this late growth being attributed to the very wet preceding summer. Vigorous regrowth occurred after complete defoliation by fire in late 1963. Decline in leaf area was due to insect damage, leaf loss and leaf-tip dieback. Insect damage was most severe on succulent new growth, while leaf loss and leaf-tip dieback were more 9revalent after frosting~ and the development of dry conditions.