Showing papers by "Michael J. Wingfield published in 1990"
TL;DR: Following a hail storm in the southern Cape Province of South Africa, about 2000 ha of pine plantations were infected by Sphaeropsis sapinea, with the greatest losses being recorded on good quality sites.
Abstract: Following a hail storm in the southern Cape Province of South Africa, about 2000 ha of pine plantations were infected by Sphaeropsis sapinea. The timber loss due to S. sapinea infection in compartments prematurely clearfelled was about 28% of volume and 55% of value of potential production. Total predicted volume of timber lost in compartments not felled prematurely was an average of 11.4%. Percentage volume lost increased with age, with the greatest losses being recorded on good quality sites.
61 citations
TL;DR: This review provides the first compilation of the literature pertaining to Cryphonectria canker and attempts to critically summarise current knowledge of the disease.
Abstract: SYNOPSIS Cryphonectria cubensis, one of a notorious group of canker pathogens of trees and the cause of a serious disease of Eucalyptus, has recently been found in South Africa for the first time. This review provides the first compilation of the literature pertaining to Cryphonectria canker and attempts to critically summarise current knowledge of the disease. Specific attention is given to the South African forestry situation and the likely impact that the disease might have in this country. Proposals for future research are also considered.
53 citations
TL;DR: A la suite d'une tempete de grele dans le sud de la province du Cap en Afrique du Sud, S. sapinea a attaque environ 2000 ha de plantations de pins, les conditions microclimatiques jouent un role majeur dans l' deperissement des pins.
Abstract: A la suite d'une tempete de grele dans le sud de la province du Cap en Afrique du Sud, S. sapinea a attaque environ 2000 ha de plantations de pins. Le developpement des symptomes, en relation avec les caracteristiques de la station et du peuplement a ete etudie dans un ensemble de placettes etablies dans des plantations de Pinus radiata. Les photographies aeriennes et les analyses au sol montrent que l'intensite de la maladie n'est pas influencee par la qualite de la station ou l'âge de la plantation, mais est inversement proportionnelle a l'altitude. Les conditions microclimatiques jouent un role majeur dans le deperissement des pins
39 citations
Journal Article•
22 citations
TL;DR: Although the genus Lophodermium includes important pathogens of Pinus spp.
Abstract: SYNOPSIS Fungi associated with needle and shoot diseases of Pinus spp. in South Africa were surveyed. Sphaeropsis sapinea caused shoot die-back of trees and seedlings of numerous pine species while Colletotrichum acutatum caused similar symptoms on seedlings of P. radiata. Dothistroma septospora was associated with needle blight of P. radiata only in the Eastern Cape Forest Region, while Cercoseptoria pini-densiflorae was associated with needle infections of a number of Pinus spp. in various parts of the country. Cyclaneusma minus, which has the potential to cause needle disease, occurred on senescent needles and needle litter of Pinus spp. throughout the country but was not associated with disease symptoms. Although the genus Lophodermium includes important pathogens of Pinus spp. only the saprophyte L. australe was found in the course of this study. A key is included to distinguish between the various fungi and possible control measures are considered.
16 citations
TL;DR: A new species of the genus Zygozyma, Z. smithiae, was recovered from frass of the ambrosia beetle, Crossotarsus externedentatus in Northern Natal.
Abstract: A new species of the genus Zygozyma, Z. smithiae, was recovered from frass of the ambrosia beetle, Crossotarsus externedentatus in Northern Natal. A description of the new species and key to the genus are given.
10 citations
TL;DR: Current knowledge of ascospore shape and development of the centrum obtained from light and electron microscope studies of Cemtocystis sensu lato is summarised.
Abstract: Ceratocystis . Ceratocxstiopsis and Ophiostoma are important pathogens of trees and some agricultural crops and have recently been found on proteas and forest trees in South Africa. Taxonomic controversy exists regarding these genera and ultrastructural studies on the development of asci, uniquely shaped ascospores and centrum structure are inadequate. This rev iew summarises current knowledge of ascospore shape and development of the centrum obtained from light and electron microscope studies of Cemtocystis sensu lato . Important questions requiring further investigations are outlined. It is furthermore proposed that additional ultrastructural studies are required to clarify the current taxonomic disagreement in this group. Such studies could also identify relationships between these fungi and other Ascomycetes.
10 citations
TL;DR: This paper reviews the available literature on the pathogen Phaeoseptoria eucalypti with a view to establishing a base for future research in South Africa.
Abstract: SYNOPSIS Phaeoseptoria eucalypti is one of the more important leaf pathogens of Eucalyptus spp. in South Africa. It is capable of causing complete defoliation of an entire plantation and the death of seedlings. This paper reviews the available literature on the pathogen with a view to establishing a base for future research in South Africa.
10 citations