High Consequence Plant Pathogens for Montana

1. High Consequence Plant Pathogens for Montana Nina Zidack Plant Disease Diagnostics Montana State University

2. High Consequence Pest List for the Great Plains • Corn cyst nematode • Philippine downy mildew • Late Wilt • Curvularia leaf spot • Soybean rust • Soybean cyst nematode • Soybean scab • Red leaf blotch • Soybean aphid • Soybean Dwarf Virus • Ergot • Plum pox • Sudden oak death • White Pine blister rust • Pine Wilt Nematode • Angular leaf spot • Rhizomania • Pierce's disease of grape

3. Potato Cyst Nematode Pale cyst nematode Globodera pallida Golden Cyst Nematode Globodera rostochiensis

4. Pale Cyst Nematode • Present on the island of New Foundland, Canada • Found in Idaho in April, 2006 • 1/9000 samples since 2003 • Idaho farm quarantined • Japan – Cut off all potato imports from US • Canada, Korea and Mexico • Cut off all potato imports from Idaho

5. Pale Cyst Nematode • Yield losses up to 80% • Affects tomatoes, eggplants, and solanaceous weeds • Poor growth, yellowing, wilting, death of foliage

6. Potato Wart

7. Spread of Potato Wart • Infected seed potatoes • Contaminated soil attached to tools and machinery • Soil attached to plants and potatoes grown in infested fields • Manure from animals fed on infected potatoes • Spores resist digestion by animals.

8. Cereal Cyst NematodeHeterodera avenae

9. Cereal Cyst Nematode • Columbia River Basin • Causes up to 50% losses

10. First Detectors • First Detector • Anyone who is likely to encounter an act or suspected act of crop bioterrorism • Producer, Agric. Consultants, County Agents, State Dept. Agric. • What can we do for First Detectors? • Training and certification • Surveillance • Registry

11. How does a sample progress through the system? • First detector encounters unusual symptoms/activity • Sample submitted to networked clinic at land-grant institution • Clinic diagnoses problem using standardized methods • If positive for one of select agents, response system activated • Proper channels of communication maintained

12. Search and Survey for Exotic Pests • Search Mode: - Normal awareness • Survey Mode: - High risk pest reported - Local detection - Distribution and spread • Alerts posted on the NPDN, and through Regional PDN’s.

13. Spatial Distribution and Scouting o o o Factors Time Pest Species Cost Ability o o o o o o o o o o o o o o o o o o o o o o o o o o o o o Uniform Random Contagious

14. Exotic Pests:Where will they come from? • Examples: • Mid West - Ralstonia solanacearum came in on infected geranium cuttings from Nigeria and Guatemala. • Michigan – Emerald Ash Borer • Mid West – Soybean Aphid • Illinois, New York – Asian Longhorn Beetle • Florida, California-Pink Hibiscus Mealybug • Florida – Soybean Rust

15. Monitoring for Exotics • Be familiar with: • Common pests • Seasonal pest patterns • Typical weather patterns

16. Monitoring for Exotics • Be familiar with: • Common pests • Seasonal pest patterns • Typical weather patterns

17. Karnal Bunt • Quarantine Issues • 71% of Montana grain exported to World Market • $700 Million Total Crop

18. Potential Sabotage Point

19. Information Flow Regional NPDN DiagnosticLaboratory USDA: NAPISAPHIS Land Grant UniversityPlant DiagnosticLaboratory StateDepartment ofAgriculture Containment and Eradication Alerts County Extension Farm Advisors First Detectors What is it?

20. Wheat – Lesion NematodePratylenchus neglectus and thornei • Dr. Alan Dyer and Wendy Lewis • Recrop production trend increasing severity • Observations in Washington, Oregon, Idaho, Utah, Colorado

21. Nematology 101 • Root lesion nematodes- Pratylenchus spp. • Wide host range • Extremely persistent • Migratory endoparasites • Symptoms in cereals • cortical necrosis of roots • stunting • chlorosis of lower leaves • increased susceptibility to secondary infection

22. Root-lesion Nematodes Pratylenchus neglectus & P. thornei

23. Spring Wheat in Soil Infested by P. thorneiat Pendleton Machete + aldicarb 27.8 bu/acre Machete control 14.3 bu/acre

24. Control • No chemical control • No biological control • Rotations are limited due to wide host range • Species specific resistances are available • Increasing populations • No-till cropping • Increase in soil-moisture • Increase in recrop acerage • Optimum nematode environment

25. Montana Nematode Survey • Assess the prevalence and impacts of RLN on Montana’s production system • Determine the possible resistances of Montana’s popular and historical wheat varieties to Pratylenchus spp.

26. Extracting Nematodes Nematodes/ kg soil

27. get counts processing of samples 180 statewide samples • Compare counts to damage thresholds. • Are nematodes important? • Identify problem areas for future study and determine predominate species.

28. Preliminary Results • Analyzed 20 samples so far (Liberty and Choteau) • 6 samples above damage threshhold (Australian data) • P. neglectus = 2500/kg soil • P. thornei = 2000/kg soil

29. Resistance Screening making inoculum open pot culturing • Determine if resistances are available in current wheat varieties. • Determine whether nematode resistances were present in historic wheat lines.

30. Sample Submission Review • Accurate Diagnosis depends on good sample

31. Samples must contain the right material: an entire plant or several plants if practical. Diseases may show up on any part of the plant. Foliage diseases Keep most roots and soil intact if possible Check for injuries, disease on the main stem/trunk

32. Dead Plants Tell no Tales • Avoid dead plants • Choose plants which show a range of symptoms: moderate to severe

33. Packaging & Shipping Good Intentions

34. Actual Results

35. Packaging and Shipping blunders Soil on foliage during shipping creates “diseases” that were not there when the sample was collected.

36. Packaging and Shipping blunders Sample Soup Don’t add water or wrap in wet paper towels

37. Good Packaging • Plastic bag to keep soil on roots • Dry paper towels to protect leaves from contact with plastic bag

38. What’s New at the Clinic? • Stripe Rust • Cephalosporium Stripe • Nitrogen Deficiency • Wheat Streak Mosaic Virus • Tan Spot • Physiological leaf spot

39. Stripe Rust - 2006

40. Rust Biology: Puccinia striiformis • Overwinters on grasses and winter wheat • Overwintered in 2006 • Infection caused by wind blown spores • Cool wet conditions (50-60ºF) • New isolates grow at higher temperatures • Winter Wheat and Spring Wheat (irrigated) • Control:Resistance and/or Fungicides

41. Resistance: • Winter Wheat and Spring Wheat* • Barley- Usually susceptible. May escape infection due to early maturity 2005 Stripe Rust Evaluations Creston, Bozeman Winter Wheat *http://plantsciences.montana.edu/Crops/

42. Fungicides: Winter Wheat and Irrigated Spring Wheat • If you didn’t plant a resistant variety, may have to apply fungicide – probably have to gain 4-5 bu to pay for the cost • If present:Spray between the period of stem elongation and heading – need to protect the flag leaf. Check the preharvest interval on the label Dryland S. Wheat? Barley?

43. Head Diseases • Fusarium scab – Has caused huge yield losses and reduced grain quality on the northern great plains since the early 1990’s • Favored by • rotations with corn – Yellowstone valley • High levels of infested residue • Sprinkler irrigation at flowering

44. Cephalosporium Stripe • Winter Wheat Disease • Residue Borne • Infects wounded roots • Frost Heave • Rotate out of Winter Wheat for 3 years, reduce inoculum by 2/3 • WW-Fallow-SW-Fallow-WW

45. Sugar Beet RhizomaniaBeet Necrotic Yellow Vein Virus • First detected 3 yrs ago • 2005 – All sugarbeet producing areas • Fungal vector – Polymyxa betae • Tare soils, contaminated equipment • 30-40% of field require rhizomania resistance

46. Mary BurrowsSmall Grains Diseases Specialist • Born in Fargo, ND • B.S. Moorhead State • Ph.D. Univ. of Wisconsin – Madison • Epidemiology of viruses and phytoplasmas in soybeans • Master Gardener • Post Doc – USDA/ARS Cornell • Aphid genetics in barley yellow dwarf transmission