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

Abstract

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; viability