The effect of frequency of defoliation on themeda triandra in the false Thornveld of the Eastern Cape

Abstract

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.

Uittreksel

Themeda triandra polle is gedurende een seisoen onderwerp aan verskillende ontblaringsfrekwensies onder toestande met besproeiing en sonder besproeiing. Herhaaldelike ontblaring (> 5 keer per jaar) het die handgesnyde opbrengs van beide vogbehandelings straf verminder. By die behandelings onder besproeiing het die wortelmassa afgeneem en die verlenging van die groeipunt is onderdruk deur ‘n verhoogde ontblaringsfrekwensie. Lootdigtheid en stoppelmassa is nie beïnvloed deur die sny‐frekwensie nie. ‘n Strawwe droogte gedurende die eksperimentele tydperk het moontlik sommige van die ontblaringsfrekwensies se reaksies op nie‐besproeide behandelings verbloem.

Additional index words:

• Herbage yield
• shoot apex
• tillers
• tufts