The effect of frequency of defoliation on Themeda triandra in the false thornveld of the eastern Cape.

Tufts of Themeda triandra were subjected to different frequencies of defoliation during a single season under irrigated and non-irrigated conditions. Frequent defoliation (> 5 times per year) severely reduced clipped yield on both moisture treatments. On irrigated treatments, root mass declined and shoot apex elevation was suppressed with increasing frequency of defoliation. Tiller densities and stubble mass were not affected by frequency of clipping. Severe drought experienced during the experimental period probably masked some of the responses to frequency of defoliation on non-irrigated treatments.Language: EnglishKeywords: alice; clipping; Defoliation; drought; Eastern Cape; False thornveld; frequency of defoliation; Herbage yield; response; root mass; Shoot apex; south africa; Themeda triandra; tiller density; Tillers; Tufts; yiel

Star grass (Cynodon nlemfuensis Harl.) In the Eastern Cape.

The growth and production of star grass in the coastal belt north east of East London, and the live mass production of tollies on this pasturage over a period of four years are discussed. The period of maximum production takes place from January to the end of February, after which it drops sharply. A live mass gain of 998 kg/ha is obtained at an optimum stocking rate of 9,06 tollies/ha. The most profitable stocking rate was calculated at 7,83 tollies/ha with a calculated live mass gain of 979 kg/ha. The calculated profit/ha at the most profitable stocking rate is R155.Keywords: afrikaans; cynodon nlemfuensis; east london; eastern cape; grass; grasses; growth; live mass gain; maximum production; optimum stocking rate; production; south africa; star grass; stocking rat

Some effects of termitaria on veld in the Eastern cape.

A survey was conducted to determine some effects of termite mounds on the veld. Termitaria were found to occupy approximately 0, 4% of the area of the paddock under investigation. Growth of grasses immediately surrounding intact termitaria increased as shown by the higher number of tillers and a high percentage of reproductive tillers. Although the plant species composition surrounding intact termitaria did not appear to differ very much from the adjacent veld, weathered termitaria revealed a change in species more typical of disturbed conditions. Nitrogen content was highest in soil from the centre of intact termitaria, but there were no significant differences in the surface soil from the edge of termitaria, from weathered mounds, or from undisturbed veld, runoff from termitaria caused increased moisture penetration surrounding the mounds. The significance of an infestation of termite mounds on the veld is discussed.Language: EnglishKeywords: botany; composition; dohne research station; eastern cape; effects; grass; grasses; Increased phytomass; moisture penetration; phytomass; plant species composition; runoff; soil nitrogen; Soil studies; south africa; species composition; termitaria; Termitaria counts; termite mounds; vegetation; Vegetation assessmen

A preliminary account of growth characteristics and seed germination of Cassia mimosoides L. in Dohne Sourveld.

An autecological study of Cassia mimosoides L., which invades mismanaged Dohne Sourveld, was initiated at the Agricultural Research Institute, Dohne. A study of growth characteristics revealed that the nature of the root distribution enabled the plant to take up moisture from superficial as well as deeper soil layers, while the position of the crown buds at or below soil level offered protection from fire damage. These characteristics plus the unpalatability of the plant to sheep and cattle placed it in a favourable position in competition with grasses. However, the relatively low-growing C. mimosoides plants appeared to be at a disadvantage in rested veld. Although seeds were dormant when released, germination took place and seeds retained their viability over a long period. Under natural conditions the germination of non-dormant seeds was controlled largely by temperature and moisture. Few seedlings established themselves in rested veld. It was suggested that a long rest period for the veld, followed by a spring burn, would be most effective in controlling the establishment of seedlings.Keywords: cassia mimosoides; cattle; competition; disturbance history; dohne sourveld; establishment; fire; germination; grasses; grassland; invasive plants; moisture; plants; root distribution; seed germination; seedlings; seeds; sheep; viabilit