Articles by Author: A Oosthuizen

Search results for A Oosthuizen

We found 54 results for you
  1. Die invloed van drie tussenrybewerkingsmetodes op opbrengs en chemiese samestelling van droëlandlusern op die oos‐transvaalse hoëveld.

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    Drie tussenrybewerkingsmetodes, skeurploeg (40 — 50 cm diep) skoffel (5 — H) cm diep) en kontrole (geen bewerking) is gedurende die 1982/83 en 1983/84 groeiseisoene in ‘n bestaande lusernstand uitgevoer. Hierdie lusern was in 0,9 m rye gevestig. Tye van...
  2. Prosedures en probleme by die gebruik van die PUTU9–87 gewasgroeisimulasiemodel vir koring onder besproeiing in die Vanderkloof-Staatswaterskema

    Prosedures en probleme by die gebruik van die PUTU9–87 gewasgroeisimulasiemodel vir koring onder besproeiing in die Vanderkloof-Staatswaterskema

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Die doel van hierdie ondersoek was om die PUTU9–87 gewasgroeisimulasiemodelte kalibreer om koringop-brengste en die grondwaterinhoud op 'n bevredlgende wyse in die Vanderkloof-Staatswaterskema te voor- spel, gegewe beperkte eksperimentele data. Opbrengste wat met PUTU voorspel is, word vergelyk met eksperimentele...
  3. Protein concentration in response to water stress in <em>Themeda triandra</em> Forsk

    Protein concentration in response to water stress in <em>Themeda triandra</em> Forsk

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The influence of water stress on the concentration of water-soluble protein growth reserves was determined during three growth stages (vegetative, pipe and reproductive) as well as in three plant parts (roots, stubble and leaves) for the indigenous C4 semi-arid grass...
  4. Root dynamics of <em>Themeda triandra</em> Forsk. in relation to water stress and defoliation at different phenological stages

    Root dynamics of <em>Themeda triandra</em> Forsk. in relation to water stress and defoliation at different phenological stages

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The impact of water stress on root growth for the indigenous apomectic C4-grass species Themeda triandra was determined over a growing season covering three growth stages (vegetative, pipe and reproductive), as well as for regrowth occurring to one, three and...
  5. Early post-cleavage stages and abnormalities identified in the embryonic development of chokka squid eggs <em>Loligo vulgaris reynaudii</em>

    Early post-cleavage stages and abnormalities identified in the embryonic development of chokka squid eggs <em>Loligo vulgaris reynaudii</em>

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Six early, post-cleavage embryonic stages for chokka squid Loligo vulgaris reynaudii eggs that were developed in an aquarium are identified and described, expanding the embryonic stages for this species from 14 to 20. The influence of water temperature on embryonic...
  6. New records of southern elephant seals <em>Mirounga leonina</em> L. on the coast of southern Africa

    New records of southern elephant seals <em>Mirounga leonina</em> L. on the coast of southern Africa

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Systematic recording of elephant-seal sightings, including 92 hitherto unpublished records, has increased the number of records on the coast of southern Africa to 130. The data set is now the largest on record for any southern continent other than Antarctica...
  7. General movements of South African (Cape) fur seals <em>Arctocephalus pusillus pusillus</em> from analysis of recoveries of tagged animals

    General movements of South African (Cape) fur seals <em>Arctocephalus pusillus pusillus</em> from analysis of recoveries of tagged animals

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Recoveries of tagged South African (Cape) fur seals totalling 10 954 are analysed. Of these, 92 per cent were harvested at their natal colony, 6 per cent at colonies other than their natal colony and 1 per cent each were...
  8. The effects of future consumption by the Cape fur seal on catches and catch rates of the Cape hakes. 3. Modelling the dynamics of the Cape fur seal <em>Arctocephalus pusillus pusillus</em>

    The effects of future consumption by the Cape fur seal on catches and catch rates of the Cape hakes. 3. Modelling the dynamics of the Cape fur seal <em>Arctocephalus pusillus pusillus</em>

    Item type: Journal Article • Journal: South African Journal of Marine Science
    The current status of and future trends for the Cape fur seal Arctocephalus pusillus pusillus population are assessed using information from aerial counts of pup abundance. The model used in the analyses is age- and sex-structured, and assumes density-dependence in...
  9. Cape fur seals trapped in trawling gear: age structure, sex ratio, seasonality and distribution

    Cape fur seals trapped in trawling gear: age structure, sex ratio, seasonality and distribution

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Biological and distributional information on Cape fur seals Arctocephalus pusillus pusillus trapped in research and commercial trawl nets were examined and compared with data from seals shot during research cruises. The male/female ratio of 150:113 for all untagged seals trapped...