Chemical effects on controlling of Rhododendron ponticum L. in western black sea forest region of Turkey

Abstract

Rhododendrons impair the natural and artificial regeneration and seedling growth in the pure and mixed forest stands in Turkey. To control the rhododendrons by employing the sprout-less herbicide applicator (SLHA) is the main goal of this study. Two studies were conducted in the western black sea region of Turkey. Each study area was selected from natural mixed stands of beech (Fagus orientalis L.) and each one contained 30 sampling plots; roundup (R) (glyphosate) and Arsenal (R) (imazapyr) herbicides were used in different concentrations. Measurements were performed after the treatment on dead, dying and active stumps; average stump height and diameter, weak/very weak and active re-sprouts, average sprout's diameter and height from every stump cut. Recovery or re-growth potential (vigor index) and basal area reduction of every stump were also calculated in every plot. The treatment efficacy was tested by using the vigor index values. Multiple variance analysis showed that SLHA treatment was very effective in reducing basal area of Rhododendron ponticum at the end of the second growing years after treatment. This means that the sprout-less herbicide applicator seems to perform well in reducing the rhododendron competition to the point of enhancing the establishment of commercial forest species. In addition, no mechanical problems were encountered in the study areas during the herbicide application process.