Growth analysis of Themeda triandra and Sporobolus fimbriatus tillers in semi-arid grassveld.

Abstract

Marked populations of Themeda triandra and Sporobolus fimbriatus tillers were sequentially harvested at fortnightly intervals both under irrigation and under unamended moisture conditions. Sampling covered a period from tiller initiation through to senescence after flowering. Tiller masses and green leaf areas were used to derive absolute growth rates, relative growth rates, net assimilation rates and leaf area ratios respectively. Growth rates of Themeda triandra were higher, or were maintained at high levels for longer than those of Sporobolus fimbriatus. Moisture stress resulted in considerably depressed growth rates. Photosynthetic efficiency of spring emerging tillers was potentially greater in midsummer, but this seasonal influence was masked by moisture stress on non-irrigated treatments.Language: English

Keywords: absolute growth rate; botany; eastern cape; false thornveld; flowering; grassveld; growth analysis; growth rate; irrigation; leaf area; leaf area ratio; leaves; moisture stress; net assimilation rate; Plant growth; plant growth indices; relative growth rate; semi-arid grassveld; south africa; sporobolus fimbriatus; themeda triandra; tiller mass; tillers; treatments; Unamended moisture conditions