Suppression of silver-leaf bitter apple (Solanum elaeagnifolium Cav.) by cultivated pasture crops under dry-land conditions: a preliminary study

Abstract

Suppression of the weed silver-leaf bitter apple (Solarium elaeagnifolium Cav.) by three pasture species, under dry-land conditions, was studied in a field trial over four seasons in the Free State Province. The pasture crops used were oats (Avena sativa), smuts finger grass (Digitarla eriantha) and lucerne (Medicago sativa), and the trial was established on dense, evenly infested cropland. Changes in shoot density and biomass of the weed were measured annually in the specific plots. The results suggest that the two perennials, particularly smuts finger grass, have the potential to suppress silver-leaf bitter apple, provided that dense stands be achieved and maintained, which will be strongly influenced by seasonal conditions in the specific environment. The annual oats, on the other hand, will apparently have little effect on the weed unless regular cultivation is carried out during the summer preceding establishment of the crop.