BLACKLEG SURVEY, DISEASE MANAGEMENT AND CANOLA
VARIETY TRIAL RESULTS
Dr. Kurtis Schroeder
Cropping Systems Agronomist & Pathologist
University of Idaho, Moscow
January 24, 2018
BLACKLEG IN IDAHO• Most important disease of canola in Canadian Prairies and
Midwest
• Estimated loss of 1% in Canada each year (~$30 million)
• Was not observed in rainfed areas of PNW until 2011 discovery
in Boundary County
• In 2014, discovered in seed production fields in Nezperce
County
• Widespread during the spring of 2015 in Idaho, Lewis,
Nezperce and Latah Counties
BLACKLEG COMPLEXDisease also referred to as Phoma stem
canker
Leptosphaeria maculans (Phoma lingam)
• Highly virulent
Leptosphaeria biglobosa
• Less virulent and destructive
BLACKLEG SYMPTOMS
BLACKLEG
LEPTOSPHAERIA MACULANS LIFE CYCLE
KEY CHARACTERISTICS THAT CAN
INFLUENCE MANAGEMENT
• Seed-borne
• Once it is established, can spread by
splash or airborne spores
• Survives in crop residue for years
BLACKLEG SURVEY (2014, 2016-2017)
SURVEY SITESLatah
Nezperce
Lewis
Clearwater
Idaho
FUNGUS ISOLATION
SUMMARY OF SURVEY
50 Locations surveyedBlackleg confirmed at 39 locations (78%)
128 isolates of Leptophaeria maculans10 isolates of L. biglobosa
Confirmed by pathogenicity tests and PCR
6562
L. maculans mating types
GENETIC RESISTANCE
• Canola has 14 identified resistance
genes (RLM)
• Corresponding 14 avirulence
9 are cloned and mapped
• B. juncea, B. rapa, B. napus
QUALITATIVE RESISTANCE
American Phytopathological Society
RecognitionNo disease
Disease
Disease Disease
CHARACTERIZATION OF ISOLATESIdentify avirulence genes by PCR and
screening differential plant lines in greenhouse
assays
14 avirulence genes
• AvrLm1-2-3-4-5-6-7-8-9-10-11
• AvrLepR1-LepR2-LepR3
PRELIMINARY SCREEN FOR AVIRULENCE
Avr geneNumber of
Isolates
AvrLm1 1
AvrLm2 0
AvrLm3 21
AvrLm4-7 120
AvrLmJ1 119
AvrLm6 123
AvrLm11 128
PCR differentials only
LEPTOSPHAERIA MACULANS RACES
15 races identified7 PCR differentials
Avr-race Number of Isolates
Avr 11 1
Avr 5 1
Avr 5-11 2
Avr 5-6-11 5
Avr 4 1
Avr 4-11 1
Avr 4-6-11 8
Avr 4-5-11 7
Avr 4-5-6 2
Avr 4-5-6-11 79
Avr 3-6-11 1
Avr 3-5-6-11 2
Avr 3-4-5-6 1
Avr 3-4-5-6-11 17
Avr 1-4-6-11 1
L. MACULANS COLLECTION FROM 2014
R genes for N. IdahoRlm5 (92%)Rlm6 (92%)Rlm7 (92%)Rlm11 (88%)LepR1 (92%)
QUALITATIVE RESISTANCE
• Type of primary seedling resistance that our wheat varieties have for protection from the stripe rust pathogen•Can break down if there are changes in the
pathogen population•Need to pyramid disease resistance or rotate
resistant lines to maintain good level of control
SEARCHING FOR NOVEL RESISTANCE
➢ Develop marker-assisted genomic selection for blackleg resistance to accelerate development of resistance
➢ Screen a diverse, worldwide collection of 400 winter canola lines for novel genetic resistance▪Qualitative (gene-for-gene)▪Quantitative – multigenic, durable resistance
BLACKLEG MANAGEMENTPrevention:• Start with disease-free, certified seed
(Phyto-sanitary certificate required for seed imported to Idaho)
• Use fungicide seed treatmentHelix Xtra, Helix Vibrance, Prosper 400,Prosper Evergol
• Protective foliar fungicides?Tilt (3), Quadris (11), Quilt (3+11), Headline (11), Priaxor Xemium (7+11), Proline 480 (3)
WINTER CANOLA BLACKLEG TRIAL
•Grangeville – planted Sept 7, 2016•24 varieties•Sprayed on Oct 11, 2016 with Priaxor (4 fl oz/A)•Sprayed on Apr 19, 2017 with Priaxor (4 fl oz/A)
Harvested Jul 28, 2017
WINTER CANOLA BLACKLEG TRIAL
Treatment Lesion Score (1-5)
Nov 11, 2016:
Priaxor 1.1 a
No fungicide 3.8 b
Apr 19, 2017
Priaxor 2.7 b
No fungicide 3.6 a
Treatment Yield (lb/A)
Priaxor 5,183 a
No fungicide 5,110 a
• Only mild lesions found at harvest• Present in both sprayed and non-
sprayed plots
SPRING CANOLA AND MUSTARD
BLACKLEG TRIAL
•Genesee – planted May 10, 2017•4 canola, 2 oriental mustard•Sprayed on Jun 2, 2017 with Priaxor (4 fl oz/A)
Harvested Jul 28, 2017
SPRING CANOLA AND MUSTARD
BLACKLEG TRIAL
Treatment Yield (lb/A)
Priaxor 838 b
No fungicide 746 a
• Tillage – bury residue
• Crop rotation – 3 years between canola or any mustard family crop
• Avoid planting adjacent to field with recent history of blackleg infection
BLACKLEG MANAGEMENT
DISEASE MANAGEMENT GUIDELINES
Pacific Northwest Plant Disease Management Handbook
➢ pnwhandbooks.org/plantdisease
Compendium of Brassica Diseases, APS Press
➢ www.apsnet.org/apsstore/shopapspress
Canola Council of Canada
➢ www.canolacouncil.org/crop-production
ACKNOWLEDGEMENTS
•Jack Brown, UI•Jim Davis, UI•Dilantha Fernando, University of Manitoba•David White•Justin Pickard•Brooklyn Collins
2017 Spring Canola Variety Trials
Jim B. Davis, Ashley Job,Megan Wingerson, and Jack Brown - UI
Alan Wernsing and Don Wysocki – OSU
Special Thanks to Kurt Schroeder
2017 Spring Canola Variety Trials
34 entries11 companies
9 sites
Funded by USDA-NIFAand
Companies who entered varieties
Spring Sites
– Bonners Ferry ID Conventional
– Moscow Conventional
– Genesee Conventional
– Craigmont Direct Seed
– Davenport WA Direct Seed
– Fairfield Direct Seed
– Dayton Direct Seed
– Pendleton OR Conventional
– Hermiston Irrigated, Conventional
Spring Canola 2017Yield by Location
0
500
1000
1500
2000
2500
lbs p
er
acre
Mean: 1512 lbs/acre
Spring Canola Yield2017, 2016, 2015, 2014, 2013
0
500
1000
1500
2000
2500
3000lb
s p
er
acre
What happened ?Flea beetles obviously… but
Late Planting Date
– Bonners Ferry ID May 18
– Moscow May 11
– Genesee May 10
– Craigmont May 9
– Davenport WA May 2
– Fairfield May 19
– Dayton May 2
– Pendleton OR April 4
– Hermiston March 23
What Else Happened?
Emergence ProblemsHard Rain / Crusting and Ponding
Flea BeetlesRain reduced seed treatment effectHigh flea beetle populationsWindy days delayed sprayingInsecticide problems?
resistance? (probably not)water pH?
Dry Summer
Cultivar BONF Mean*
Minimum 202 1,089
Maximum 1,399 1,838
Mean 800 1,512
Brett Young 5545 Clearfield 920 1,680
CPS DynaGro 200 Clearfield 1,399 1,691
CPS DynaGro 540G RR 1,357 1,671
HyCLASS 930 RR 1,009 1,838
HyCLASS 955 RR 781 1,733
InVigor L140P Liberty Link 1,088 1,607
Star 402 RR 1,083 1,607
Select Spring Canola Cultivars
* Mean of 8 dryland sites.
More data is available in flyers and online.
http://www.cals.uidaho.edu/brassica/ “For Growers” Link
Questions?
Jim Davis <[email protected]>208-885-4266
http://www.cals.uidaho.edu/brassica/
Special Thanks to Houck Farms