Development of biological control strategies against sirex noctilio (Fabricius) on Sappi Forests (Ltd) Landholdings in the summer rainfall regions of South Africa
- Authors: Verleur, Peter Marcel
- Date: 2009
- Subjects: Pests -- Biological control -- South Africa , Nonindigenous pests -- Control
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10741 , http://hdl.handle.net/10948/1273 , Pests -- Biological control -- South Africa , Nonindigenous pests -- Control
- Description: The commercial forest industry in South Africa is predominantly dependent on large tracts of exotic monoculture plantations. While this simplifies management practice, there is always the inherent danger posed by introduced pests and diseases. Classical biological control is usually the most effective control method against introduced exotic pests. Climatic factors and seasonal differences may negatively affect the ability of the natural enemies to establish successfully at the new location. Successful establishment of the natural enemies usually results in control over the pest within four years. Sirex noctilio naturally occurs in the mediterranean countries of Europe and North Africa. It is the only member of the Siricid family capable of killing living pine trees. Sirex noctilio was accidentally introduced into New Zealand from Europe during the early 1900s. It has since been found in Australia, Brazil, Argentina South Africa and Chile. Initial biological control in New Zealand and Tasmania was through the release of Siricid specific parasitoid wasps from Europe and North America. The discovery of the accidental introduction of the entomophagous nematode Beddingia siricidicola and its subsequent artificial culturing for release provided the platform for the biological control methodology, which brought the Sirex woodwasp under control. The methods and natural enemies used in New Zealand and Australia were introduced by the South American countries and in the Western Cape of South Africa. Successful biological control was achieved in the Western Cape within two years after the initial introduction of the nematode B. siricidicola. The migration of S. noctilio into the summer rainfall regions of South Africa occurred in the absence of the associated natural enemies. This resulted in rapid population growth of the pest and substantial damage was caused to plantations of Pinus patula in the Eastern Cape and KwaZulu-Natal. Initial attempts at introducing B. siricidicola during 2004 were not very successful. This study contributes to the understanding and adaptation of the biological control methods to the summer rainfall climate. The key finding was that in the summer rainfall climate, only the bottom third of nematode inoculated S. noctilio infested trees produced parasitized adults during the emergence period. A comparative study was done on log samples from S. noctilio infested trees collected in the Western Cape and KwaZulu-Natal. iv An adapted nematode inoculation technique for pulpwood plantations in the summer rainfall regions was developed and implemented in mass inoculations with B. siricidicola during 2007 and 2008. Locally available herbicides were tested for suitability of use in the establishment of trap trees, which would attract ovipositing S. noctilio females in situations where low numbers of the woodwasp occur. Determination of the levels of natural B. siricidicola parasitism in S. noctilio adults during the 2008 emergence period indicate successful establishment of the nematode in KwaZulu-Natal. Successful introduction of the parasitoid wasp Ibalia leucospoides into the summer rainfall regions has also been achieved.
- Full Text:
- Date Issued: 2009
- Authors: Verleur, Peter Marcel
- Date: 2009
- Subjects: Pests -- Biological control -- South Africa , Nonindigenous pests -- Control
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10741 , http://hdl.handle.net/10948/1273 , Pests -- Biological control -- South Africa , Nonindigenous pests -- Control
- Description: The commercial forest industry in South Africa is predominantly dependent on large tracts of exotic monoculture plantations. While this simplifies management practice, there is always the inherent danger posed by introduced pests and diseases. Classical biological control is usually the most effective control method against introduced exotic pests. Climatic factors and seasonal differences may negatively affect the ability of the natural enemies to establish successfully at the new location. Successful establishment of the natural enemies usually results in control over the pest within four years. Sirex noctilio naturally occurs in the mediterranean countries of Europe and North Africa. It is the only member of the Siricid family capable of killing living pine trees. Sirex noctilio was accidentally introduced into New Zealand from Europe during the early 1900s. It has since been found in Australia, Brazil, Argentina South Africa and Chile. Initial biological control in New Zealand and Tasmania was through the release of Siricid specific parasitoid wasps from Europe and North America. The discovery of the accidental introduction of the entomophagous nematode Beddingia siricidicola and its subsequent artificial culturing for release provided the platform for the biological control methodology, which brought the Sirex woodwasp under control. The methods and natural enemies used in New Zealand and Australia were introduced by the South American countries and in the Western Cape of South Africa. Successful biological control was achieved in the Western Cape within two years after the initial introduction of the nematode B. siricidicola. The migration of S. noctilio into the summer rainfall regions of South Africa occurred in the absence of the associated natural enemies. This resulted in rapid population growth of the pest and substantial damage was caused to plantations of Pinus patula in the Eastern Cape and KwaZulu-Natal. Initial attempts at introducing B. siricidicola during 2004 were not very successful. This study contributes to the understanding and adaptation of the biological control methods to the summer rainfall climate. The key finding was that in the summer rainfall climate, only the bottom third of nematode inoculated S. noctilio infested trees produced parasitized adults during the emergence period. A comparative study was done on log samples from S. noctilio infested trees collected in the Western Cape and KwaZulu-Natal. iv An adapted nematode inoculation technique for pulpwood plantations in the summer rainfall regions was developed and implemented in mass inoculations with B. siricidicola during 2007 and 2008. Locally available herbicides were tested for suitability of use in the establishment of trap trees, which would attract ovipositing S. noctilio females in situations where low numbers of the woodwasp occur. Determination of the levels of natural B. siricidicola parasitism in S. noctilio adults during the 2008 emergence period indicate successful establishment of the nematode in KwaZulu-Natal. Successful introduction of the parasitoid wasp Ibalia leucospoides into the summer rainfall regions has also been achieved.
- Full Text:
- Date Issued: 2009
An assessment of the challenges and successes experienced when implementing the six sigma methodology in Continental Tyre South Africa
- Authors: Kanakana, Mukundeleli Grace
- Date: 2006
- Subjects: Six sigma (Quality control standard) , Total quality control , Total quality management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8553 , http://hdl.handle.net/10948/531 , Six sigma (Quality control standard) , Total quality control , Total quality management
- Description: Globalisation has opened up international markets for South African companies, but has also introduced competition in the domestic market. As a result, South African organisations are forced to attain global efficiency levels if they are to compete on the world market as well as maintain their domestic market share. Organisations have to come with creative methods that can enhance their competitiveness, one of them being the Six Sigma. Six Sigma is a measurement-based strategy that focuses on process improvement and variation reduction as a means towards performance improvement. The methodology has a reputation of success, however a number of organisations believe that the methodology is not relevant to their specific competitive needs. Six Sigma is seen as another continuous improvement tool applicable to first world country organisations which will fade away with time. The study was undertaken to find out challenges and successes of implementing a Six Sigma methodology at Continental Tyre SA. The findings of the study revealed that the experience of implementing Six Sigma methodology at Continental Tyre SA is similar to those experienced by first world organisations. It is concluded that Six Sigma methodology can improve organisation processes and yield financial benefits irrespective of organisation location or background. However, organisations must follow a systematic guideline when implementing the methodology. The study provides recommendations on how Continental Tyre SA can align their strategy in order to achieve organisational objectives. The following recommendations were made: Roll out Six Sigma to support departments; Align the strategy to address critical success factors; Improve project turnover time and measure the success on financial savings and number of projects completed.
- Full Text:
- Date Issued: 2006
- Authors: Kanakana, Mukundeleli Grace
- Date: 2006
- Subjects: Six sigma (Quality control standard) , Total quality control , Total quality management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8553 , http://hdl.handle.net/10948/531 , Six sigma (Quality control standard) , Total quality control , Total quality management
- Description: Globalisation has opened up international markets for South African companies, but has also introduced competition in the domestic market. As a result, South African organisations are forced to attain global efficiency levels if they are to compete on the world market as well as maintain their domestic market share. Organisations have to come with creative methods that can enhance their competitiveness, one of them being the Six Sigma. Six Sigma is a measurement-based strategy that focuses on process improvement and variation reduction as a means towards performance improvement. The methodology has a reputation of success, however a number of organisations believe that the methodology is not relevant to their specific competitive needs. Six Sigma is seen as another continuous improvement tool applicable to first world country organisations which will fade away with time. The study was undertaken to find out challenges and successes of implementing a Six Sigma methodology at Continental Tyre SA. The findings of the study revealed that the experience of implementing Six Sigma methodology at Continental Tyre SA is similar to those experienced by first world organisations. It is concluded that Six Sigma methodology can improve organisation processes and yield financial benefits irrespective of organisation location or background. However, organisations must follow a systematic guideline when implementing the methodology. The study provides recommendations on how Continental Tyre SA can align their strategy in order to achieve organisational objectives. The following recommendations were made: Roll out Six Sigma to support departments; Align the strategy to address critical success factors; Improve project turnover time and measure the success on financial savings and number of projects completed.
- Full Text:
- Date Issued: 2006
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