Articles by Author: Shawn Mclaren

Search results for Shawn Mclaren

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  1. Effect of temperature on the severity of pre-and post-emergence damping-off and seedling blight of grain sorghum (<em>Sorghum bicolor</em>)

    Effect of temperature on the severity of pre-and post-emergence damping-off and seedling blight of grain sorghum (<em>Sorghum bicolor</em>)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The effect of temperature regimes on seedling diseases of grain sorghum (Sorghum bicolor (L.) Moench), was investigated in growth cabinets and for five planting dates in field trials. The period from planting to seedling emergence was increased by low pre-emergence...
  2. Effect of sugary disease exudates on germination, seedling development and predisposition to seedling diseases of sorghum (<em>Sorghum bicolor</em>)

    Effect of sugary disease exudates on germination, seedling development and predisposition to seedling diseases of sorghum (<em>Sorghum bicolor</em>)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Sorghum harvested for seed from Claviceps africana-infected fields becomes coated with sugary disease exudates in which the fungal spores are borne. The role of exudates in the inhibition of seed germination, seedling growth and predisposition to seedling diseases was investigated...
  3. Efficacy of systemic fungicides and timing of preventative sprays in the control of sugary disease of grain sorghum (<em>Sorghum bicolor</em>)

    Efficacy of systemic fungicides and timing of preventative sprays in the control of sugary disease of grain sorghum (<em>Sorghum bicolor</em>)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Eight systemic fungicides, benomyl, bitertanol, carbendazim/flusilazol, CG169374, procymidone, propiconazole, terbuconazole and triadimenol, were evaluated in two separate field trials during the 1989/90 and 1990/91 seasons to determine their efficacy against the control of sugary disease of sorghum with a single...
  4. Resistance of sorghum hybrids to ergot caused by <em>Claviceps africana</em>

    Resistance of sorghum hybrids to ergot caused by <em>Claviceps africana</em>

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Thirty-one sorghum hybrids were evaluated for ergot ‘escape’ resistance at Bethlehem and Potcherstroom during the 1996/97 and 1997/98 seasons. Trials were designed so that flowering and artificial inoculation occurred over a range of flowering dates and thus, ergot potentials Non-linear...
  5. Evaluation of sorghum hybrids for resistance to the root rot complex

    Evaluation of sorghum hybrids for resistance to the root rot complex

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Seventy-one sorghum hybrids were evaluated for root rot resistance at Bethlehem and Potchefstroom, South Africa, from 1995/96 to 1998/99. Mean root rot severity ranged from 30.3% in PAN8494 to 41.3% in PAN8061 and root rot severity of hybrids differed significantly...
  6. Efficacy of fungicides in the control of ergot (<em>Claviceps africana</em>) in sorghum <em>(Sorghum bicolor</em>) hybrid seed production

    Efficacy of fungicides in the control of ergot (<em>Claviceps africana</em>) in sorghum <em>(Sorghum bicolor</em>) hybrid seed production

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Ergot is a disease of unfertilized sorghum ovaries. It is particularly prevalent in seed production where losses may average 10–20% per annum. Protection of the ovary during the critical period of flower opening to fertilization could reduce losses and increase,...
  7. Effect of soil nutrient status on severity of seedling diseases and root rot of sorghum (<em>Sorghum bicolor</em>)

    Effect of soil nutrient status on severity of seedling diseases and root rot of sorghum (<em>Sorghum bicolor</em>)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The hybrid NK283 was subjected to a range of nutrient element concentrations to determine their effect on predisposition of sorghum to seedling diseases and root rot. Emergence was not affected by soil nutrient status. Similarly N, P and K did...
  8. Relationship between ergot and grain mould development in sorghum (<em>Sorghum bicolor</em> (L.) Moench)

    Relationship between ergot and grain mould development in sorghum (<em>Sorghum bicolor</em> (L.) Moench)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    A greenhouse experiment was conducted to determine the influence of sorghum ergot on the incidence of grain mould pathogens and on damage to sorghum grains. Grain mould pathogens used were Curvularia lunata, Fusarium subglutinans and Phoma sorghina. Inoculation with the...
  9. Reaction of South African soybean cultivars to rust caused by <em>Phakopsora pachyrhizi</em>

    Reaction of South African soybean cultivars to rust caused by <em>Phakopsora pachyrhizi</em>

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Soybean rust was recorded in South Africa in February 2001 in the Vryheid area of KwaZulu-Natal, from where it spread throughout production areas east of the escarpment. Management of the disease is presently, based on fungicide spray programs. Commercial soybean...