Articles by Author: Simon Du Plooy

Search results for Simon Du Plooy

We found 82 results for you
  1. On the financial interpretation of risk contributions: An analysis using Quantile Simulation

    On the financial interpretation of risk contributions: An analysis using Quantile Simulation

    Item type: Journal Article • Journal: Investment Analysts Journal
    This paper tests whether the financial interpretation of risk contributions (Qian, 2006), as measured by marginal change in volatility, holds when accounting for fat tails in the asset return distributions. This important result is the theoretical foundation of risk-based portfolios,...
  2. Essential Oils in the Leaf, Bark and Seed of Mopane (<em>Colophospermum mopane</em>)

    Item type: Journal Article • Journal: South African Forestry Journal
    Essential oils were obtained from the mature leaves, bark and seed of mopane (Colophospermum mopane). Over 50 compounds were detected and the major compound from all three plant sources was found to be α-pinene. The oil from the bark was...
  3. Editorial

    Editorial

    Item type: Journal Article • Journal: South African Journal of Philosophy
  4. Editorial

    Editorial

    Item type: Journal Article • Journal: South African Journal of Philosophy
  5. Editorial

    Editorial

    Item type: Journal Article • Journal: South African Journal of Philosophy
  6. Storage root formation at individual nodes of the sweet potato (<em>Ipomoea batatas</em> (L.) Lam)

    Storage root formation at individual nodes of the sweet potato (<em>Ipomoea batatas</em> (L.) Lam)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Little or no information is available on the contribution of individual subterranean nodes to the storage root formation in sweet potatoes. Therefore, two field trials were conducted where apical vine cuttings of various cultivars were planted vertically or horizontally, with...
  7. Effect of BP1, BP3 and Quince A rootstocks, at three planting densities, on precocity and fruit quality of ‘Forelle’ pear (<em>Pyrus communis</em> L.)

    Effect of BP1, BP3 and Quince A rootstocks, at three planting densities, on precocity and fruit quality of ‘Forelle’ pear (<em>Pyrus communis</em> L.)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    ‘Forelle’ pear trees (Pyrus communis L.) were established at the Bien Donné experimental farm in the Western Cape Province of South Africa on BP1, BP3 and Quince A rootstocks at three planting densities, i.e., 889, 1667 and 2857 trees. ha...
  8. Effect of pruning on yield and quality of hydroponically grown cherry tomato (<em>Lycopersicon esculentum</em>)

    Effect of pruning on yield and quality of hydroponically grown cherry tomato (<em>Lycopersicon esculentum</em>)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The commercial importance of cherry tomatoes is continuously increasing in the South African retail market, with fruit size playing an important role. The effect of pruning on yield and quality of two cherry tomato cultivars (Naomi and Josefina) with an...
  9. Effect of plant spacing on growth and yield of lettuce (<em>Lactuca sativa</em> L.) in a soilless production system

    Effect of plant spacing on growth and yield of lettuce (<em>Lactuca sativa</em> L.) in a soilless production system

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Lettuce production in re-circulating hydroponic systems is done on a limited scale in South Africa with conflicting information on the recommended spacing for optimal yield and quality in such systems. The development and yield of four lettuce (Lactuca sativa L.)...
  10. Comparative performance of tomato cultivars cultivated in two hydroponic production systems

    Comparative performance of tomato cultivars cultivated in two hydroponic production systems

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Cultivar selection for different hydroponic production systems is an important management decision, potentially impacting the tomato grower’s profitability. Knowledge on the performance of tomato cultivars, in specific hydroponic systems (open-bag and closed system) under South African conditions, is still very...