Articles by Author: Steven D Verryn

Search results for Steven D Verryn

We found 45 results for you
  1. Comparison of the tolerance of <em>Pinus patula</em> seedlings and established trees to infection by <em>Fusarium circinatum</em>

    Comparison of the tolerance of <em>Pinus patula</em> seedlings and established trees to infection by <em>Fusarium circinatum</em>

    Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science
    Since the first appearance of Fusarium circinatum in South Africa in 1990, foresters have been challenged with poor field survival of Pinus patula seedlings at establishment. One of the best long-term solutions is to improve the genetic tolerance of P...
  2. Estimates of genetic parameters and genetic gains for growth traits of two <em>Eucalyptus urophylla</em> populations in Zululand, South Africa

    Estimates of genetic parameters and genetic gains for growth traits of two <em>Eucalyptus urophylla</em> populations in Zululand, South Africa

    Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science
    In South Africa, Eucalyptus urophylla is an important species due to its disease tolerance to fungal diseases such as Crysoporthe austroafricana and the Coniothyrium sp. cankers. It is mainly planted as a parental species in a hybrid combination with E...
  3. Growth and dynamic modulus of elasticity of <em>Pinus patula</em> × <em>Pinus tecunumanii</em> hybrids in Mpumalanga, South Africa

    Growth and dynamic modulus of elasticity of <em>Pinus patula</em> × <em>Pinus tecunumanii</em> hybrids in Mpumalanga, South Africa

    Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science
    Field establishment of South Africa’s most important commercial pine species, Pinus patula, is severely hampered by the pitch canker fungus, Fusarium circinatum. Importantly, hybrids between P. patula and other pine species tolerant to the pitch canker fungus, such as P...
  4. Genetic parameters and genotype by environment interaction of <em>Eucalyptus grandis</em> populations used in intraspecific hybrid production in South Africa

    Genetic parameters and genotype by environment interaction of <em>Eucalyptus grandis</em> populations used in intraspecific hybrid production in South Africa

    Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science
    In South Africa, Eucalyptus grandis is an important species due to its fast growth and general suitability of its timber for a range of products. However, E. grandis is susceptible to fungal diseases such as Crysoporthe austroafricana and Coniothyrium sp...
  5. Effect of Genotype-by-Environment Interaction on the Wood Properties and Qualities of Four-year-old <em>Eucalyptus grandis</em> and <em>E. grandis</em> Hybrids

    Item type: Journal Article • Journal: South African Forestry Journal
    The effect of environment on growth-stress splitting, wood density, fibre length, shrinkage and heartwood content was studied using 31 five-year-old eucalypt clones, mostly Eucalyptus grandis and E. grandis-based hybrids, grown in replicated trials at 26 sites. An analysis of variance...
  6. Divide and rule: on the rationalization of vocabulary teaching

    Divide and rule: on the rationalization of vocabulary teaching

    Item type: Journal Article • Journal: South African Journal of Linguistics
    Aangesien Engels die verkose onderrigmedium van die oorgrote meerderheid van Suid-Africa se nie-Engelstaliges is, is 'n besondere poging nodig om leerlinge vir die oorgang na Engels vroeg in hul skoolloop-bane voor te berei—'n oorgang wat juis saamval met 'n radikale...
  7. The Use of a Simple Genetic Algorithm as a Tree Breeding Selection Technique

    The Use of a Simple Genetic Algorithm as a Tree Breeding Selection Technique

    Item type: Journal Article • Journal: The Southern African Forestry Journal
    A genetic ranking procedure for breeding which is not dependant on statistical selection methods such as Best Linear Unbiased Prediction (BLUP) and Best Linear Prediction (BLP) is described and results of tests on simulation breeding data are presented. A simple...
  8. A repeatability study of trait assessment in a <em>Pinus patula</em> breeding programme

    A repeatability study of trait assessment in a <em>Pinus patula</em> breeding programme

    Item type: Journal Article • Journal: The Southern African Forestry Journal
    A repeatability study of tree height, diameter at breast height (DBH), stem and crown form assessments was undertaken. Trees were measured four times by two independent teams. The repeatability of the five traits was estimated. The effect of repeatability on...
  9. An investigation into the occurrence and nature of genotype by environment interaction in <em>Pinus patula</em>

    An investigation into the occurrence and nature of genotype by environment interaction in <em>Pinus patula</em>

    Item type: Journal Article • Journal: The Southern African Forestry Journal
    This study was conducted as part of a joint venture between the tree improvement teams of Safcol and the CSIR to develop a breeding, production and conservation strategy for Pinus patula.
  10. The Cross-Cultural Validity of the Child Sexual Abuse Myth Scale: A Preliminary Investigation

    The Cross-Cultural Validity of the Child Sexual Abuse Myth Scale: A Preliminary Investigation

    Item type: Journal Article • Journal: Journal of Psychology in Africa
    The cross-cultural validity of the Child Sexual Abuse Myth Scale was examined in samples of adolescents and young adults drawn from three countries: South Africa (n = 200), Korea (n = 200), and Sweden (n = 200). Participants completed the...