What Lurks in Your Canola Field: Disease Surveys of Debra McLaren & Anastasia Kubinec AAFC-Brandon and MAFRI-Carman

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1 What Lurks in Your Canola Field: Disease Surveys of 2009 Debra McLaren & Anastasia Kubinec AAFC-Brandon and MAFRI-Carman

2 Studies / Collaborators Survey of Canola Diseases in Manitoba Surveillance and dispersal of Plasmodiophora brassicae in western Canada D. McLaren, A. Kubinec, R. Kutcher, S. Strelkov, F. Dokken, P. Northover, S-F. Hwang, R. Howard and K. Turkington

3 Manitoba Team for Canola Survey Manitoba Canola Growers Association AAFC Deb McLaren, Tom Henderson, Danny Hausermann and Teri Kerley MAFRI Anastasia Kubinec, Brian Jack, Stephanie Jersak, Hilmar Johnson, Lionel Kaskiw, Ingrid Kristjanson and Kristen Phillips Canola Council of Canada Derwyn Hammond

4 Canola Fields for Survey in Manitoba 140 canola fields in Manitoba 60 of these fields = soil samples for clubroot Bruce Barker Bruce Barker

5 Red = disease survey + soil sample Green = disease survey only

6 In The Field 20 paces 100 paces 100 paces

7 Sanitation Practices for Canola Survey Wear disposable booties and disposable rubber gloves Sterilize soil sampling equipment in bleach after leaving field but before entering vehicle Eliminate transport of infected soil outside of the sealed soil sample. Do not drive into the field

8 Soil Collection for Clubroot Assessment Collect 1 L soil from all 5 points of W combined If entrance to field is obvious, collect soil from 5 points in area limited to the vicinity of this approach. To collect soil, clear away crop residue and scoop approx. 1 cup soil from top 5-10 cm Place in paper bags to air-dry.

9 Canola Diseases Sclerotinia Stem Rot Blackleg Alternaria Black Spot Aster Yellows Fusarium Wilt Foot Rot Clubroot

10 Canola Council of Canada Sclerotinia Stem Rot: Sclerotinia sclerotiorum

11 Frayed Stems and Presence of Sclerotia

12 Premature Ripening & Crop Lodging Canola Council of Canada Canola Council of Canada

13 Rating for Sclerotinia Stem Rot Main stem lesions that affected the entire plant were recorded separately from any lesion in the upper branches or pods

14 Sclerotinia Stem Rot in Manitoba (2009) Canola Council Crop Region No. of Crops Prevalence (%) Incidence Central East./Interlake Northwest Southwest Province

15 Sclerotinia in Canola: Previous Years Year No. of Crops Prevalence (%) Incidence

16 Blackleg: Leptosphaeria maculans Whitish, round to irregular lesions on leaves dotted with pycnidia Lesions on leaves become papery and dry Brown to greyish black lesions, become sunken cankers, girdling the stem Black lines inside base of stem Premature plant death

17 Blackleg

18 Damage due to blackleg basal stem cankers Blackleg on canola pod and upper stem

19 Blackleg Rating System Main stem lesions that affected the entire plant were recorded separately from any lesion(s) in the upper branches or pods Cankers formed early in the season may girdle the stem (virulent strain L. maculans) Weakly virulent strain (L. biglobosa) also causes stem lesions but superficial, nongirdling and occur late in the season so don t affect yield

20 Blackleg in Manitoba Canola Fields (2009) CCC Basal Cankers Upper Stem Lesions Crop Region Percent Prevalence Incidence Percent Prevalence Incidence Central East./Inter Northwest Southwest Province

21 Blackleg in Canola: Previous Years CCC Basal Cankers Upper Stem Lesions Crop Region Percent Prevalence Incidence Percent Prevalence Incidence

22 Alternaria Black Spot Canola Council of Canada Canola Council of Canada Brown to black small, round spots on pods and stems As disease progresses, spots become black to gray with black border Leaves die and drop off Pods become dry and sunken and split prematurely

23 Alternaria Black Spot Canola Council of Canada

24 Rating Scale for Alternaria Black Spot Alternaria black spot on canola Conn et al. 1990

25 Alternaria Black Spot Crop Region No. of Crops Prevalence (%) Disease Severity Central <1 East./Interlake <1 Northwest <1 Southwest <1 Province <1 * Generally a 1% infection of pods or stems translates into a 1% yield loss.

26 Fusarium Wilt (F. oxysporum f.sp. conglutinans) Canola Council of Canada

27 In some plants, yellowing & necrosis affects one side of stem, or individual branches Healthy Distinct colour: grey-green with a red-pink cast

28 Fusarium Wilt Crop Region No. of Crops Prevalence (%) Incidence Central 49 2 <1 East./Interlake <1 Northwest Southwest 48 4 <1 Province <1

29 Fusarium Wilt : Previous Years Crop Region No. of Crops Prevalence (%) Incidence <

30 Aster Yellows Diseases of Field Crops in Canada, CPS

31 Aster Yellows Transmitted by aster leafhoppers Malformation of the floral parts Round to oval blue-greenish, hollow bladder like formations

32 Aster Yellows Crop Region No. of Crops Prevalence (%) Incidence Central <1 East./Interlake <1 Northwest <1 Southwest <1 Province <1

33 Foot Rot Diseases of Field Crops in Canada Early symptoms of light brown lesions on roots (taproot and/or main lateral roots) below soil line Lesions enlarge, leaving a stubby root Plants ripen prematurely

34 Foot Rot Foot rot was observed in 2% of canola fields Disease incidence was <1% in Central, E/I and NW regions. No foot rot observed in SW region.

35 Clubroot : Plasmodiophora brassicae Sowiak Turkington

36 Clubroot Healthy Root Young Root Galls Strelkov

37 Range of Clubroot Symptom Severity Healthy Sowiak Diseases of Field Crops in Canada Turkington

38 Disintegration and spore release Decaying Clubroot Galls

39 Why is Clubroot of Concern? Serious disease of canola, mustard and other crops in the cabbage family Spreads through resting spores in soil Resting spores are extremely long lived This can be problematic under tight rotations Infestations near 20% cause yield loss of 10% Yield and quality (oil content) of the seed are reduced

40 Clubroot Life Cycle of Pathogen

41 Clubroot Status (Oct. 2009) Clubroot confirmed in 454 fields since fields visited & 49 new cases identified in municipalities & City of Edmonton Additional cases suspected but not confirmed Presence of P. brassicae inoculum also confirmed in Saskatchewan (1 field in 2008) Presence in Manitoba in one canola field in 2005.

42 What is being done about Clubroot? April 2007 clubroot added as a declared pest to Alberta s Agricultural Pest Act. June 2009 clubroot declared a pest in SK under The Pest Control Act. Not a legislated pest in Manitoba yet but this is in progress Required to take steps to destroy, control and prevent spread of clubroot.

43 Potential for Clubroot Infestations Climex Modelling Turkington, Olfert & Weiss

44 Clubroot Management Strategies Use long rotations between crops 4 yrs or more Practice good sanitation to restrict movement of contaminated soil Soil conservation practices to reduce erosion Scout regularly to ID causes of wilting, stunting, yellowing and premature ripening Avoid common untreated seed because earth tag on seed from infested fields could introduce resting spores to clean fields. Risk of spreading clubroot through contaminated seed is much less than through transporting contaminated soil on field equipment.

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46 Summary Clubroot Alberta: New cases of clubroot continue to be identified Saskatchewan: One case of clubroot 2008; no symptoms in 2009; soil sample results pending Manitoba: No clubroot symptoms in 2009; soil samples Sclerotinia: Similar levels in past few years Blackleg: prevalence of basal cankers increased; that of stem cankers relatively the same. Fusarium wilt: prevalence reduced over years Survey of Manitoba canola fields: will continue as a collaboration between AAFC, MAFRI, MCGA, and CCC

47 Acknowledgements: Technical Staff at AAFC-Brandon Tom Henderson Danny Hausermann Teri Kerley