Articles by Author: R H M Cross

Search results for R H M Cross

We found 44 results for you
  1. Effectiveness of paraquat on the Ngongoni veld of the natal mistbelt

    Effectiveness of paraquat on the Ngongoni veld of the natal mistbelt

    In a series of experiments designed to test the use and efficiency of paraquat (when applied as Gramoxone) in controlling the growth of veld grasses in the Ngongoni Sourveld, it was shown that when applied at as low a rate...
  2. Effect of selective defoliation on species in mixed swards

    Effect of selective defoliation on species in mixed swards

    Sown pastures of Paspalum dilatatum (and other species) in Natal are subject to degradation by Eragrostis plana (mshiki) invasion. The ratio between these two grasses, growing together in small plots, was governed primarily by the relative heights, and secondarily by...
  3. The production potential of <em>pennisetum clandestinum</em> in the midlands and on the south coast of natal

    The production potential of <em>pennisetum clandestinum</em> in the midlands and on the south coast of natal

    Growth curves from two sources of nitrogen at levels ranging from 0 kg N to 240 kg N/ha indicated DM yields of 2 000 kg/ha to 13 000 kg/ha from Pennisetum clandestinum at various localities in the Natal Region. Once...
  4. Maintaining the nutritive value of <em>pennisetum clandestinum</em> for milk production

    Maintaining the nutritive value of <em>pennisetum clandestinum</em> for milk production

    The amount of milk which can be produced by cows grazing Pennisetum clandestinum (kikuyu) is dependant on several management factors. These factors relate to the nutritive value and intake of the herbage on offer and include palatability, TDN, protein and...
  5. Productivity and stability of various Grass‐legume mixtures with different intensities of defoliation and levels of nitrogen fertilisation

    Productivity and stability of various Grass‐legume mixtures with different intensities of defoliation and levels of nitrogen fertilisation

    Three trials were established at Cedara under dryland conditions to determine the production, persistence and value of Trifolium repens cv. Ladino, Trifolium pratense cv. Kenland red and Desmodium uncinatum cv. Silverleaf. These legumes were row‐planted into Pennisetum clandestinum (kikuyu); Cynodon...
  6. NOTE ON SOME CHARACTERISATIONS OF UNBOUNDED WEAKLY COMPACT OPERATORS

    NOTE ON SOME CHARACTERISATIONS OF UNBOUNDED WEAKLY COMPACT OPERATORS

    Item type: Journal Article • Journal: Quaestiones Mathematicae
    Some well known properties of bounded weakly compact operators in Banach spaces are shown to be valid for arbitrary operators in normed spaces.
  7. THE ESSENTIAL STATE DIAGRAM FOR LINEAR RELATIONS IN NORMED SPACES

    THE ESSENTIAL STATE DIAGRAM FOR LINEAR RELATIONS IN NORMED SPACES

    Item type: Journal Article • Journal: Quaestiones Mathematicae
    The state diagram for linear operators of Goldberg [G, II.4.11] is shown to be valid for the essential states (i.e., finite dimensional variants of the standard states) of linear relations in normed spaces.
  8. The diet and ecological importance of <em>Illex coindetii</em> and <em>Todaropsis eblanae</em> (Cephalopoda: Ommastrephidae) in Irish waters

    The diet and ecological importance of <em>Illex coindetii</em> and <em>Todaropsis eblanae</em> (Cephalopoda: Ommastrephidae) in Irish waters

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Between November 1993 and May 1997, the stomach contents of trawl-caught Illex coindetii and Todaropsis eblanae from the edge of the continental shelf west and south-west of Ireland were examined. When visually assessed, 82.1% of the I. coindetii stomachs and...
  9. CRITICAL POINT DRYING AS A PREPARATIVE TECHNIQUE FOR SCANNING ELECTRON MICROSCOPY AND ITS APPLICATION IN LIMNOLOGY

    CRITICAL POINT DRYING AS A PREPARATIVE TECHNIQUE FOR SCANNING ELECTRON MICROSCOPY AND ITS APPLICATION IN LIMNOLOGY

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The preservation technique of critical point drying for use with the scanning electron microscope is described. A study of the periphyton community development on the aquatic macrophyte, Potamogeton pectinatus L. from the littoral zone of Swartvlei, southern Cape Province, is...
  10. Multivalued linear projections

    Multivalued linear projections

    Item type: Journal Article • Journal: Quaestiones Mathematicae
    A multivalued linear projection operator P defined on linear space X is a multivalued linear operator which is idempotent and has invariant domain. We show that a multivalued projection can be characterised in terms of a pair of subspaces and...