Articles by Author: Jonathan Roberts

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  1. The use of glyphosate for the management of secondary coppice regrowth in a <em>Eucalyptus grandis</em> × <em>E. urophylla</em> coppice stand in Zululand, South Africa

    The use of glyphosate for the management of secondary coppice regrowth in a <em>Eucalyptus grandis</em> × <em>E. urophylla</em> coppice stand in Zululand, South Africa

    Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science
    In South Africa, commercial eucalypt stands may be regenerated through the stepwise reduction of coppice shoots following felling. The development of secondary coppice regrowth following these reduction operations results in competition with the remaining stems, possibly resulting in a reduction...
  2. Desiccant herbicides tested for the preparation of fire-break tracer lines, South Africa

    Desiccant herbicides tested for the preparation of fire-break tracer lines, South Africa

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Over the past 32 years, 75 599 ha of plantations within South Africa have been lost through fire. Fire prevention, in the form of firebreaks on landholding boundaries, are required (by law) by landowners from whose land a fire might...
  3. The nutritive value, yield and botanical composition of irrigated pastures as influenced by nitrogen fertilizing<sup>1</sup>

    The nutritive value, yield and botanical composition of irrigated pastures as influenced by nitrogen fertilizing<sup>1</sup>

    The performances of grass and grass/legume swards at three levels of nitrogen were compared under irrigation over a three‐year period. The swards were grazed by dairy cows and the influence of nitrogen on dry matter yield, protein content, protein yield...
  4. Pasture quality and its relation to utilization

    Pasture quality and its relation to utilization

    The paper evaluates those functions of the grazing‐animal/pasture complex which are influenced by management. The contribution of pasturage to animal production is determined primarily by environment and secondarily by defoliation. In pasture quality evaluation, those approaches which employ both digestibility...
  5. Pasture science as a university discipline

    Pasture science as a university discipline

    Pasture Science at South African Universities owes its origin to early realization of the vital role of vegetation management in soil conservation programs. Being a study of the principles and practice of grazing land maintenance and utilization, Pasture Science must...
  6. Application of veld management in South Africa ‐ an analysis of progress

    Application of veld management in South Africa ‐ an analysis of progress

    The widespread deterioration of veld in South Africa necessitates an analysis of the reasons for this serious state of affairs. Although approximately 34 per cent of farms have the facilities to apply conservation farming, less than 10 per cent of...
  7. Why multicamp layouts?

    Why multicamp layouts?

    Although it has become standard practice in Southern Africa to recommend grazing systems based on a maximum of five camps, there are indications that the use of multicamp layouts, employing a greater number of camps per herd, may increase the...
  8. Assessment of veld condition and trend

    Assessment of veld condition and trend

    Advice on veld management generally assumes that the productivity of veld can be improved by management. There is thus a need in agricultural extension work, where botanical surveys are impractical, for a basis on which changes in veld condition can...
  9. Habitat preferences of twenty‐seven grasses

    Habitat preferences of twenty‐seven grasses

    A statistical analysis of species/habitat data from 521 sites in the Orange Free State is presented with a view to establishing relationships for use in aerial photograph interpretation. Quantitative data on the association between 27 common grasses and the following...