National Contingency Plan for Tilletia contraversa, the cause of Dwarf Bunt of Wheat Part I Pest Risk Assessment October 2007 Written and prepared by: Gordon Murray, NSW DPI Dominie Wright, DAFWA Citation: Murray GM, Wright DG (2007) ‗National Contingency Plan for Tilletia contraversa, the Cause of Dwarf Bunt of Wheat. Part I: Pest Risk Assessment‘. Plant Health Australia, Canberra, ACT, Australia. vi + 16 pp. The National Contingency Plan for Tilletia contraversa has four manuals: Part I: Pest risk assessment, with background information on the pathogen and disease Part II: Preventative Measures, the current and recommended actions to reduce the risk of an incursion Part III: Field Manual, for use by the incident manager and teams in the emergency response Part IV: Diagnostic Protocol, for use by the diagnostic laboratories The authors of Part I: Dr Gordon Murray is a principal research scientist employed by NSW Department of Primary Industries. He is located at the EH Graham Centre for Agricultural Innovation, Wagga Wagga Agricultural Institute. Dr Murray is a plant pathologist with major interests in the diseases of plants grown on farms in southern and central New South Wales. His main work is on winter cereals, winter pulse crops and canola. He studies the effect that plant diseases have on production and quality, and the possible controls such as management, rotation and plant breeding. Ms Dominie Wright is a plant pathologist employed by the Western Australian Department of Agriculture and Food. She is located at the South Perth Laboratories where she specialises in the diagnosis of field crop diseases by providing a diagnostic service to the farmers and agribusiness consultants. Ms Wright also specialises in the diagnosis of bacterial diseases in horticultural and field crops. Ms Wright enjoys writing training courses and compiling research into contingency plans for exotic pathogens. Address: Dr Gordon M. Murray Wagga Wagga Agricultural Institute Private Bag Wagga Wagga, NSW 2650 Australia Phone: 02 6938 1999 Fax: 02 6938 1809 Email: [email protected] Ms Dominie Wright Department of Agriculture and Food Locked Bag 4 Bentley Delivery Centre, WA 6983 Australia Phone: 08 9368 3875 Fax: 08 9474 2840 Email: [email protected] Plant Health Australia, Suite 5, 4 Phipps Close, Deakin, ACT 2600, Australia. Email: [email protected] Web site: www.planthealthaustralia.com.au PART I – PEST RISK ANALYSIS Contents EXECUTIVE SUMMARY .............................................................................................................. V 1. INTRODUCTION................................................................................................................ 1 2. DWARF BUNT OF WHEAT .................................................................................................. 2 2.1 The pathogen and the disease ............................................................................. 2 2.2 Symptoms ............................................................................................................ 2 2.3 Host Range .......................................................................................................... 3 3. EPIDEMIOLOGY ............................................................................................................... 4 3.1 Disease Cycle ...................................................................................................... 4 3.2 Environmental conditions for infection .................................................................. 4 3.3 Distribution ........................................................................................................... 5 3.3.1 Known distribution ....................................................................................... 5 3.3.2 Potential Distribution ................................................................................... 6 4. ECONOMICS AND MARKETING ........................................................................................ 10 4.1 Impact on production.......................................................................................... 10 4.1.1 Yield losses ............................................................................................... 10 4.1.2 Long-term contamination of contaminated land ........................................ 10 4.1.3 Additional costs of field control treatments ................................................ 10 4.1.4 Post-harvest effects on product quality and processing ............................ 10 4.1.5 Allied industries dependent on wheat ........................................................ 11 4.2 Impact on the market for wheat .......................................................................... 11 4.3 Impact of regulatory controls .............................................................................. 11 4.3.1 Detection on imported goods. ................................................................... 11 4.3.2 Erroneous detection in Australian grain ..................................................... 11 5. CONTROL ..................................................................................................................... 12 5.1 Fungicides.......................................................................................................... 12 5.2 Breeding ............................................................................................................ 12 5.3 Cultural .............................................................................................................. 12 6. PEST RISK ASSESSMENT ............................................................................................... 13 6.1 Assessment of Likelihood .................................................................................. 13 6.1.1 Entry potential ........................................................................................... 13 6.1.2 Establishment potential ............................................................................. 13 6.1.3 Spread potential ........................................................................................ 13 6.2 Overall entry, establishment and spread potential .............................................. 13 6.3 Assessment of consequences............................................................................ 14 6.3.1 Economic impact ....................................................................................... 14 6.3.2 Environmental impact ................................................................................ 14 6.3.3 Social impact............................................................................................. 14 October 2007 NATIONAL CONTINGENCY PLAN FOR DWARF BUNT OF WHEAT iii PART I – PEST RISK ANALYSIS 6.4 Combination of likelihood and consequences to assess risks ............................ 14 7. CONCLUSIONS .............................................................................................................. 15 7.1 Surveillance ....................................................................................................... 15 7.2 Diagnostics ........................................................................................................ 15 7.3 Training .............................................................................................................. 15 7.4 Research Options .............................................................................................. 15 8. REFERENCES ................................................................................................................ 16 iv NATIONAL CONTINGENCY PLAN FOR DWARF BUNT OF WHEAT October 2007 PART I – PEST RISK ANALYSIS EXECUTIVE SUMMARY Dwarf bunt, also called ―TCK smut‖, is one of five bunt and smut diseases that affect wheat throughout the world. None of these bunts and smuts is toxic to humans or animals but the bunts in particular can affect the appearance and smell of grain products. Three bunts and smuts occur in Australia and most other wheat growing countries: these are common bunt (caused by Tilletia caries and Tilletia laevis), loose smut (Ustilago tritici) and flag smut (Urocystis agropyri). The two that do not occur in Australia are Karnal bunt (Tilletia indica) and dwarf bunt (Tilletia contraversa). Karnal bunt and dwarf bunt have a restricted distribution and are subject to quarantine regulations by many countries. Karnal bunt is dealt with in a separate contingency plan. Dwarf bunt is a serious disease for international trade because it reduces grain quality and has a restricted distribution, leading to some countries placing restrictions on the import of wheat from areas where the disease occurs. Dwarf bunt does not occur in Australia and so these trade restrictions do not apply to our wheat. However, because any report of dwarf bunt occurring in Australia could have implications for trade, the Grains Council determined that a contingency plan for dwarf bunt be developed. The dwarf bunt contingency plan is divided into four parts: Part I — Pest Risk Assessment, developed from background information on the pathogen and the disease Part II — Preventative Measures, giving the current and recommended actions to reduce the risk of an incursion Part III — Field Manual, for use by the incident manager and teams in the emergency response Part IV — Diagnostic Manual, for use by the diagnostic laboratories Part I — Pest Risk Assessment Dwarf bunt only occurs in wheat growing areas where