Articles by Author: N P Steyn

Search results for N P Steyn

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  1. Die invloed van verskillende waterregimes op Up-to-date aartappels I. Vegetatiewe ontwikkeling, fotosintesetempo en stomatadiffusieweerstand

    Die invloed van verskillende waterregimes op Up-to-date aartappels I. Vegetatiewe ontwikkeling, fotosintesetempo en stomatadiffusieweerstand

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Drie grondwaterregimes (20, 50 en 70% onttrekking van plantbeskikbare water) is gedurende herfsaanplan- tings in 1987 en 1988 op Up-to-date aartappels toegepas om die invloed daarvan op groei en ontwikkeling te ondersoek. Twee fisiologiese parameters van plantwaterstremming, naamlik, fotosintesetempo en...
  2. Die invloed van verskillende waterregimes op Up-to-date aartappels II. Opbrengs, grootteverspreiding, kwaliteit en waterverbruik

    Die invloed van verskillende waterregimes op Up-to-date aartappels II. Opbrengs, grootteverspreiding, kwaliteit en waterverbruik

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Drie besproeiingsbehandelings (20, 50 en 70% onttrekking van plantbeskikbare water) is toegepas ten einde die optimum peil van grondwateronttrekking by aartappels te bepaal. Die proef is gedurende die 1987 en 1988 herfsseisoene uitgevoer. Totale waterverbruik van behandelings is bereken en...
  3. Leaf characters of various tea clones in relation to quality

    Leaf characters of various tea clones in relation to quality

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The leaves of ten different tea clones were investigated to explore the possibility that structural differences exist between clones and that morphological characters relate to the quality of the infusion. Our results revealed a significant negative correlation between TF-values and...
  4. AMMI analysis of potato cultivar yield trials

    AMMI analysis of potato cultivar yield trials

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Potatoes, Solanum tuberosum (L), are cultivated in South Africa under a variety of different climates and seasons. The wide environmental variation encountered and the confirmed occurrence of genotype-environmental interaction necessitates the use of criteria, other than averages, in the evaluation...
  5. The effects of tillage systems on soil bulk density and penetrometer resistance of a sandy clay loam soil

    The effects of tillage systems on soil bulk density and penetrometer resistance of a sandy clay loam soil

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Concern has been expressed that reduced tillage systems may lead to excessive soil compaction, with a negative impact on crop growth. The objectives of this study were to determine the effects of different tillage systems, namely, minimum tillage (disc and...
  6. Fotosintesetempo en stomatadiffusieweerstand van aartappels soos beïnvloed deur waterstremming

    Fotosintesetempo en stomatadiffusieweerstand van aartappels soos beïnvloed deur waterstremming

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Die invloed van waterstremming in aartappelplante op netto fotosintesetempo en stomatadiffusieweerstand is tydens 'n herfsaanplanting ondersoek. Watertoediening is op 14, 28 en 42 dae na opkom gestaak om sodoende verskillende waterstremmingsperiodes tydens die groeiseisoen toe te pas. Hierdie Studie is...
  7. Die invloed van grondbewerking op vroeë wortelontwikkeling en biomassa van koringkultivars (<em>Triticum aestivum</em> L.)

    Die invloed van grondbewerking op vroeë wortelontwikkeling en biomassa van koringkultivars (<em>Triticum aestivum</em> L.)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Dit is bekend dat 'n goeie wortellengte en/of worteldigtheid in die eerste paar weke belangrik is om goeie saailingvestiging te verkry. Die doel van hierdie studie was om die uitwerking van minimumbewerking (wisselgangskotteleg en vlerkskaar), beitelploeg- en konvensionele bewerking op...
  8. A comparison of culture methods for tobacco (<em>Nicotiana tabacum</em>) anthers

    A comparison of culture methods for tobacco (<em>Nicotiana tabacum</em>) anthers

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Three different anther culture methods for the South African tobacco cultivars C11 × WOSB and CDL 28 were tested. The yield of haploid plantlets produced using a solidified or double-layer medium was significantly higher than with the use of a...
  9. SEMANTIESE KLASSE

    Item type: Journal Article • Journal: Taalfasette
  10. DIE MENTALISME VAN 'N ANTI-MENTALIS

    Item type: Journal Article • Journal: Taalfasette