Project Number
CRI GP 01
Project title
Proof and quantification of grapevine leafroll disease vector dispersal and disease spread mechanisms
Project leader
Pietersen, G
Institution
Citrus Research International. Department of Microbiology and Plant Pathology
Team members
Pietersen, G
Krüger, K
Kotze, A
Schwerdfeiger, M
Project description
Various grapevine leafroll spread mechanisms occur simultaneously in vineyards. Infrequent or less easily identifiable mechanisms, for example wind dispersal, are masked by the more dominant or obvious mechanisms, for example secondary spread. As control strategies become increasingly better at controlling known spread mechanisms, these other ‘hidden’ dispersal mechanisms are likely to become more obvious and will require specific control interventions. It is therefore important to identify these and to quantify them in order to develop control strategies to them. The ultimate aim of the first aspect of the project is therefore to annually monitor the spatial progression of grapevine leafroll in vineyards in which control strategies to the known dispersal mechanisms are being applied. This must be done over the entire duration of this project. Based on this, the remaining dispersal mechanisms can be inferred and ultimately control strategies to them developed and assessed.
Grapevine leafroll spread mechanisms obtained in project WW 07-16 were inferred by the data rather than proven by just following spatio-temporal dynamics of case studies. These need to be proven and various aspects of the mechanisms quantified to fully implement efficient and effective control strategies. Firstly spread of the disease by scion material and rootstocks must be unequivocally demonstrated, the way that they are spatial distributed in new vineyards determined, and the potential latent phase of each of these sources determined within nurseries and new vineyards. Secondly, dispersal of mealybugs on man and implements must be demonstrated and strategies to counter this assessed. Thirdly the major means of secondary spread must be demonstrated (mealybug motility determined and differentiated from potential intra-row root union formation).
Presentation(s)
Pietersen, G, Spreeth, N, Oosthuizen, T W, Van Rensburg, A, Tooth, D and Rossouw, N. 2005. An integrated control strategy to prevent the spread of grapevine leafroll disease on Vergelegen Wine Estate – a model for the South African wine industry. Paper presented at the 3rd International Congress of the South African Society for Enology and Viticulture. 7-8 November, Cape Town, South Africa.
Pietersen, G. 2007. Progress report. Presentation at the Winetech Information Day. 2 May, Stellenbosch, South Africa.
Pietersen, G. 2007. Virus epidemiology. Presentation at the Winetech Virus Information Day. 4 May, Stellenbosch, South Africa.
Pietersen, G. 2008. Grapevine leafroll disease in South Africa. Presentation to the Martinborough Producers. 6 March, New Zealand.
Pietersen, G. 2008. Current studies on leafroll control in South Africa. Presentation to the Martinborough Producers. 6 March, New Zealand.
Pietersen, G. 2008. Grapevine leafroll disease in South Africa. Presentation to the Napier Producers. 7 March, New Zealand.
Pietersen, G. 2008. Current studies on leafroll control in South Africa. Presentation to the Napier Producers. 7 March, New Zealand.
Pietersen, G. 2008. Grapevine leafroll disease in South Africa. Presentation to the Gisborne Producers. 10 March, New Zealand.
Pietersen, G. 2008. Current studies on leafroll control in South Africa. Presentation to the Gisborne Producers. 10 March, New Zealand.
Pietersen, G. 2008. Current studies on leafroll control in South Africa. Presentation to producers. 12 March, Marlborough, New Zealand.
Pietersen, G. 2008. Grapevine leafroll disease in South Africa. Presentation to New Zealand Wine. 13 March, Nelson, New Zealand.
Pietersen, G. 2008. Current studies on leafroll control in South Africa. Presentation to New Zealand Wine. 13 March, Nelson, New Zealand.
Pietersen, G, Spreeth, N, Oosthuizen, W T, Van Rensburg, A, Tooth, D and Rossouw, N. 2009. Control of grapevine leafroll at Vergelegen: 2002-2008. Paper presented at the 46th Congress of the Southern African Society for Plant Pathology. 25-28 January, Gordon’s Bay, South Africa.
Pietersen, G. 2009. Grapevine leafroll disease in South Africa. Presentation to producers. 19 May, Israel.
Jooste, A E C, Goszczynski, D E, Burger, J T and Pietersen, G. 2009. Identification of a third molecular variant of grapevine leafroll-associated virus-3 (GLRaV-3) associated with grapevine leafroll disease in vineyards of the Western Cape. Paper presented at the 46th Southern African Society for Plant Pathology Conference. 25-28 January, Gordon’s Bay, South Africa.
Pietersen, G. 2009. A South African experience in combating and controlling grapevine leafroll disease. Paper presented at the Romeo Bragato Conference. 20-24 August, Napier, New Zealand.
Pietersen, G. 2009. Principles and problems related to rouging and replacement strategies. Paper presented at the Romeo Bragato Conference. 20-24 August, Napier, New Zealand.
Pietersen, G. 2009. Grapevine leafroll epidemiology and control in South Africa. Paper presented at the Romeo Bragato Conference. 20-24 August, Napier, New Zealand.
Jooste, A E C, Maree, H J, Pietersen, G, Goszczynski, D E and Burger, J T. 2009. Identification and distribution of three divergent molecular variants of GLRaV-3 in South African vineyards. Paper presented at the 16th International Council for the Study of Viruses and Virus-like Diseases of the Grapevine. 31 August – 4 September Dijon, France.
Pietersen, G, Spreeth, N, Oosthuizen, W T, Van Rensburg, A, Lottering, D, Tooth, D and Rossouw, N. 2009. A case study of control of grapevine leafroll disease spread on Vergelegen Wine Estate, South Africa, 2002-2008.Paper presented at the 16th International Council for the Study of Viruses and Virus-like Diseases of the Grapevine. 31 August – 4 September Dijon, France.
Douglas, N, Pietersen, G and Kruger, K. 2009. A real time RT-PCR assay for the detection and quantification of grapevine leafroll-associated virus 3 (GLRaV-3) in Vitis vinifera L. (Vitaceae) and Planoccus ficus (Signoret) (Hemiptera; Pseudoccidae). Paper presented at the 16th International Council for the Study of Viruses and Virus-like Diseases of the Grapevine. 31 August – 4 September Dijon, France.
Pietersen, G, Oosthuizen, W T, Jooste, E, Filippin, L, Bertazzon, N and Angelini, E. 2009. Shiraz disease and grapevine yellows in South Africa. Paper presented at the 16th International Council for the Study of Viruses and Virus-like Diseases of the Grapevine. 31 August – 4 September Dijon, France.
Pietersen, G. 2010. Review of grapevine leafroll disease research and application 2003-2010. Presentation at the Winetech Information Day. 4 May, Vredendal, South Africa.
Pietersen, G. 2010. Successful control of grapevine leafroll disease at Vergelegen Wine Estate. Presentation at the Winetech Information Day. 4 May, Vredendal, South Africa.
Pietersen, G. 2010. Review of grapevine leafroll disease research and application 2003-2010. Presentation at the Winetech Information Day. 5 May, Malmesbury, South Africa.
Pietersen, G. 2010. Successful control of grapevine leafroll disease at Vergelegen Wine Estate. Presentation at the Winetech Information Day. 5 May, Malmesbury, South Africa.
Pietersen, G. 2010. Review of grapevine leafroll disease research and application 2003-2010. Presentation at the Winetech Information Day. 6 May, Worcester, South Africa.
Pietersen, G. 2010. Successful control of grapevine leafroll disease at Vergelegen Wine Estate. Presentation at the Winetech Information Day. 6 May, Worcester, South Africa.
Pietersen, G. 2010. Review of grapevine leafroll disease research and application 2003-2010. Presentation at the Winetech Information Day. 11 May, Robertson, South Africa.
Pietersen, G. 2010. Successful control of grapevine leafroll disease at Vergelegen Wine Estate. Presentation at the Winetech Information Day. 11 May, Robertson, South Africa.
Pietersen, G. 2010. Review of grapevine leafroll disease research and application 2003-2010. Presentation at the Winetech Information Day. 12 May, Stellenbosch, South Africa.
Pietersen, G. 2010. Successful control of grapevine leafroll disease at Vergelegen Wine Estate. Presentation at the Winetech Information Day. 12 May, Stellenbosch, South Africa.
Pietersen, G. 2010. Principles of grapevine leafroll disease control. Presentation to the Constantia Interest Group. 26 May, Constantia, South Africa.
Pietersen, G. 2010. Successful control of grapevine leafroll disease at Vergelegen Wine Estate. Presentation to the Constantia Interest Group. 26 May, Constantia, South Africa
Pietersen, G. 2010. The management of grapevine leafroll disease. Presentation at the Terrason Grapevine Training Programme. 2 June, Wellington, South Africa.
Pietersen, G. 2011. Control of grapevine leafroll in South Africa. Presentation at the Winetech Virus Day. 24 May, Stellenbosch, South Africa.
Pietersen, G. 2011. Progress on control of grapevine leafroll in South Africa. Presentation to the Uniwines Producers’ Study Group. 21 June, Rawsonville, South Africa.
Article
Pietersen, G. 2010. Beheer van wingerd rolblaarsiekte in Suid-Afrika, WineLand, (p. 102-106)
Pietersen, G. 2011. New strategies to control leafroll (Part 1): Vineyard control measures first step in South Africa’s virus defense, Australian and New Zealand Grapegrower and Winemaker, Mnth Jul (570) (p. 24-25)
Pietersen, G. 2011. New strategies to control leafroll (Part 2) Australian and New Zealand Grapegrower and Winemaker, Mnth Aug (570) (p. 24-27)