Scouting card for bacterial leaf streak of wheat

Here is our latest edition to the Prairie Crop Disease Monitoring Network (PCDMN) suite of disease scouting cards.  Over the past 5-10 years there has been increasing observations of bacterial leaf streak (BLS) in wheat as well as bacterial issues in other cereal crops. Unfortunately in 2020 there were reports across the Prairie region, especially in Saskatchewan and Alberta, of bacterial issues in cereals, including wheat.  Observations reported by farmers, consultants, and pathologists suggest in some wheat fields BLS may have resulted in moderate yield losses.  

Unfortunately, management options for BLS are limited and involve two main strategies: 

1) Avoiding seed known or suspected to be infected with the BLS pathogen, as seed-borne inoculum is one of the main sources of this pathogen; 

2) Extending rotational intervals to at least two years between wheat crops to reduce the amount of infected residue, which can be another BLS source.  

It is critically important to correctly identify symptoms in the field using information outlined in the new BLS scouting card as well as other sources.  Symptoms may be confused with fungal leaf spots of wheat such as tan spot, the septoria complex and stripe rust.  If typical symptoms are observed one may be able to differentiate BLS from tan spot, the septoria complex, and stripe rust.  However, if symptoms are not distinct then a laboratory diagnosis will be needed.  Access these links for scouting cards and symptoms:

• Bacterial leaf streak
• Tan spot
• Speckled leaf blotch
• Leaf and glume blotch
• Cereal rust symptoms (PCDMN scouting cards in development)

One other observation that can help to identify a potential BLS issue, is that farmers may experience a lack of symptom control when applying one or more fungicide applications during the growing season.  Although this may indicate potential issues with fungicide resistance, especially for speckled leaf blotch, it can also suggest that the observed symptoms may not be due to the fungal pathogens that cause cereal leaf spot complex or leaf/stripe rust.  Our current suite of fungicide-based seed treatments and in-crop foliar fungicides will not control BLS.

Conditions that favour development of BLS include: 1) irrigation; and 2) Severe weather events that result in torrential rain, hail, very strong winds, thundershowers and soil particle erosion.  These severe weather events may lead to plant tissue damage, which provides an avenue of entry to the BLS pathogen along with natural plant openings such as stomata. The BLS bacterial pathogen is spread by plant-to-plant contact, insects, and rain splashing or wind-driven rain.  

Given these recent BLS observations, efforts are underway in the pathology, breeding and seed testing communities to develop diagnostic tools for bacterial issues in cereals, and to provide more information related to potential varietal differences in relation to BLS susceptibility. 

Other sources of information on bacterial leaf streak include the following:

• https://cropprotectionnetwork.org/resources/articles/diseases/bacterial-streak-and-black-chaff-of-wheat
• https://www.ag.ndsu.edu/ndipm/publications/wheat/documents/pp1566.pdf
• https://plantpathology.ca.uky.edu/files/ppfs-ag-sg-02.pdf
• https://cropwatch.unl.edu/2019/wheat-disease-update-bacterial-streak-and-black-chaff
• https://extension.umn.edu/small-grains-pest-management/bacterial-leaf-streak-and-black-chaff-small-grains#risk-factors-1373413
• https://www.grainews.ca/features/detect-and-avoid-bacterial-leaf-streak/
• https://mnwheat.org/2019/08/bacterial-leaf-streak-what-northern-plains-wheat-growers-need-to-know/
• https://swfrec.ifas.ufl.edu/hlb/database/pdf/00000926.pdf

The Prairie Crop Disease Monitoring Network (PCDMN) would like to graciously thank the following individuals for their assistance and collaboration on the PCDMN BLS scouting card: Mike Harding, Alberta Agriculture and Forestry (AAF); Alireza Akhavan, Saskatchewan Ministry of Agriculture; and David Kaminski, Manitoba Agriculture and Resource Development.

The PCDMN would also like to graciously thank Mike Harding, AAF, and Rebecca Wiebe, CORE AG INPUTS, Carstairs, AB for photos of BLS symptoms.  

Ascochyta/mycosphaerella disease assessment protocols

During June and July, crop scouting for the ascochyta/mycosphaerella complex in field pea is critical for assessing risk and gauging the need for and timing of an in-crop fungicide application.  However, late season crop scouting is also important as it can be used to assess the prevalence, severity and impact of these disease issues.  Where unsprayed check strips or areas have been left in the field, late season assessments can be used to assess the impact and benefit of spraying in relation to leaf disease management and crop productivity. 

Assessment protocols and scouting information are now available at the links below for the ascochyta/mycosphaerella complex in field pea.

The main leaf diseases in field peas: 

1. Ascochyta blight caused by the fungus Mycosphaerella pinodes;
2. Ascochyta leaf and pod spot caused by the fungus Ascochyta pisi

Protocols and scouting information can be found at the following links:

Ascochyta/mycosphaerella assessment protocols

Ascochyta/mycosphaerella disease scouting info

Blackleg of canola survey protocols and scouting information

Blackleg is one of the key diseases faced by Prairie canola producers and has largely been kept in check with the use of resistant varieties and crop rotation.  However, over the past 10-20 years there have been concerns regarding observed shifts in blackleg pathogen virulence in response to the major gene resistance used in a number of varieties.  Changes in virulence patterns emphasize the critical need to stay on top of this disease; producers and crop scouts can play a critical role by scouting fields to monitor blackleg and detect any unexpected increases in disease levels on resistant varieties.  For blackleg a critical time for scouting is later in the season to assess the prevalence, severity and impact of this disease issue.  When assessing blackleg incidence and severity, it is critical to correctly identify symptoms of blackleg and differentiate these from normal or premature canola crop ripening due to a range of abiotic and biotic factors.  Recent Prairie research has shown limited responses to in-crop fungicide when resistant varieties are grown, and especially where this resistance is still highly effective. 

Protocols and scouting information can be found at the following links:

Protocols for blackleg surveying in canola

Blackleg scouting information

Suggested protocols for assessing the incidence and severity of sclerotinia stem rot of canola

During late June and July, crop scouting in canola is critical for assessing sclerotinia stem rot risk and gauging the need for and timing of an in-crop fungicide application.  However, late season crop scouting is also important as it can be used to assess the prevalence, severity and impact of this disease issue.  Where unsprayed check strips or areas have been left in the field, late season assessments can be used to assess the impact and benefit of spraying in relation to sclerotinia stem rot management and crop productivity.  When assessing sclerotinia stem rot incidence and severity, it is critical to correctly identify symptoms of stem rot and differentiate these from normal or premature canola crop ripening due to a range of abiotic and biotic factors. 

A detailed overview of suggested sampling protocols can be found at the following link: 

Prairie Crop Disease Monitoring Network, Sclerotinia Stem Rot Assessment Protocols, Summer 2020.

A companion document is also available that outlines additional sampling suggestions as well as typical symptoms of sclerotinia stem rot and symptoms due to other factors that are not sclerotinia stem rot.  This companion document is available at the following link:   

Guide to scouting and identification of sclerotinia stem rot of canola.

Fusarium damaged kernel symptoms

In-crop scouting at the late milk to early dough stage of development in your wheat and barley may indicate potential issues with fusarium head blight.  Make sure to follow up with an assessment of the harvested grain.  Here is an @PCDMN disease info card that outlines typical fusarium damaged kernel (FDK) symptoms as well as symptoms due to other issues that may be confused with fusarium head blight damage in harvested grain.

Testing of representative samples from harvested grain by a seed testing lab can help in terms of potential grade and mycotoxin issues, while identifying possible solutions/opportunities.  

PCDMN fusarium head blight info card

The latest PCDMN fusarium head blight info card is available.  The card covers symptoms and management of fusarium head blight of wheat, caused primarily by Fusarium graminearum.

Link to the FHB of wheat info card

Latest PCDMN disease info card

The latest PCDMN disease info card is available.  The card covers symptoms and management of fusarium head blight of barley, caused primarily by Fusarium graminearum.

Fusarium head blight of barley info card

Developing a series of protocols for the practical surveillance of field crop diseases

The Prairie Crop Development Network (PCDMN) is developing a series of recommended protocols for the practical surveillance of field crop diseases.   

During June and July, crop scouting for various Prairie field crop diseases is critical for assessing risk and gauging the need for and timing of an in-crop fungicide application.  However, late season crop scouting is also important as it can be used to assess the prevalence, severity and impact of these disease issues.  Where unsprayed check strips or areas have been left in the field late season assessments can be used to assess the impact and benefit of spraying in relation to leaf spot management and crop productivity.  

Recommended protocols for cereal leaf spot assessment are now available at the PCDMN Blog using the following link: Cereal Leaf Spot Assessment Protocols

Another critical aspect of in-field surveillance activities is the need to use caution to avoid inadvertently spreading crop pests into or from the fields being surveyed.  See the Biosecurity Protocols section for key information outline protocols and standards for limiting the risk of crop pest spread while conducting plant disease surveillance activities.  

Wind trajectories and regional rust development in relation to Prairie cereal rust risk (Jul 14-20)

Here is a mini update regarding wind trajectories and regional rust development in relation to Prairie cereal rust risk.  

The full report can be found at: July 14-20, 2020 cereal rust risk update

Given the state of maturity and harvest in the USA on winter wheat, these regions no longer represent a significant source of rust inoculum for the Prairie region and the weekly full PCDMN updates for 2020 have finished for these areas.  However, spring cereals in these regions may still represent a source of rust inoculum although the acreage of spring wheat is typically lower than that of winter wheat, depending on the State.

With the appearance of stripe rust in ten southern Alberta municipalities, at Beaverlodge in the Country of Grande Prairie, in the Fort St. John/Dawson Creek region of BC, and at four locations in Saskatchewan, farmers in these regions should be on the look out for stripe rust in wheat.  In addition, farmers in regions north and east to northeast of southern Alberta should be on alert as southerly winds may transport stripe rust spores.  Moreover, trajectory analysis from July 14-20, 2020 has indicated a total of 13 of 29 locations where wind trajectories previously passed over the stripe rust area of southern AB.  Special focus should be on wheat fields seeded to varieties rated as susceptible or moderately susceptible.  Also, given the appearance of crown rust in the Mannville region of Alberta, as well as at Carman, Manitoba, oat growers in this area need to be on the look out for crown rust.

Growers with very late seeded fields of wheat or perhaps barley for swath grazing may want to be especially diligent in terms of scouting for stripe rust.  Over the years some of the most severe stripe rust epidemics have occurred in wheat fields seeded late (e.g. June) for swath grazing, especially where the variety was susceptible.  

Weekly Cereal Rust Risk Report (Jul 7-13)

The 10th wind trajectory/cereal rust risk report is available for July 7-13, 2020.  Overall the risk of stripe rust movement from the Pacific Northwest (PNW) is low-moderate.  Although, winter wheat is approaching maturity in the PNW and is being harvested in some regions, the spring wheat crop has just headed out and is still at a stage where further stripe rust could develop in the next week to two weeks.  However, the acreage of spring wheat is about a 1/3 of the acreage of winter wheat (520,000 acres versus 1,700,000 acres) and growers are being encouraged to spray with a fungicide to limit further rust development (https://quickstats.nass.usda.gov/results/E8A8F30A-19BD-341C-A8DF-B2FD3A78ACBB).

Given the appearance of stripe rust in seven southern Alberta municipalities, at Beaverlodge in the Country of Grande Prairie, and at three locations in Saskatchewan, farmers in these regions should be on the look out for stripe rust in wheat.  In addition, farmers in regions north and east to northeast of southern Alberta should be on alert as southerly winds may transport stripe rust spores.  Special focus should be on wheat fields seeded to varieties rated as susceptible or moderately susceptible.  Also, given the appearance of crown rust in the Mannville region of Alberta, as well as at Carman, Manitoba, oat growers in this area need to be on the look out for crown rust.

Link: Full report for July 7-13, 2020

Stripe Rust Reportings in Alberta

On July 15, 2020, Mike Harding, Plant Pathologist, Alberta Agriculture and Forestry, Brooks, AB, reported the observation of stripe rust in two more Alberta municipalities.  Stripe rust of wheat was noted in the MD of Willow Creek, AB, and the MD of Pincher Creek, AB.

Updated report as of 2:00 pm, July 15, 2020

Growers in areas where stripe rust has been found are encouraged to scout wheat fields, especially those seeded to susceptible (S) or moderately susceptible varieties (MS).  Late seeded fields may still be at a stage when fungicide can be applied.  Stripe rust resistance/susceptibility ratings can be found in the provincial variety guides:

Alberta variety guide

Saskatchewan variety guide

Manitoba variety guide

Mike Harding also put together a graphic outlining wheat reactions to stripe rust and it is attached.  It is based on the 2020 Alberta Seed Guide.  Thanks Mike!

Stripe and Leaf Rust of Wheat and Crown Rust of Oat for Canadian Prairies

The next wind trajectory cereal rust risk report (July 7-13, 2020) for the Prairie region of Canada is being prepared.  The main focus will be on stripe rust movement from the Pacific Northwest as winter wheat crops in the Texas to Nebraska corridor are either approaching maturity or have been harvested.  

However, here is an updated map on the reported observations of stripe and leaf rust of wheat and crown rust of oat in the Prairie region as of noon on July 14, 2020.  Updated maps will be posted as reports are received.  

July 14, 2020 map indicating where stripe and leaf rust of wheat, and crown rust of oat have been reported


Updated map with crown rust observation at Carman, MB by D. Kaminski, Agriculture and Resource Development, Manitoba, July 14, 2020

Welcome to the new Prairie Crop Disease Monitoring Network Blog!

The Prairie Crop Disease Monitoring Network (PCDMN) is a coordinated field crop disease monitoring program for the prairies. The PCDMN’s main focus is to provide timely information about crop diseases on the Prairies and to highlight effective disease management approaches.  The Blog is designed to help the PCDMN share disease information with the Canadian agricultural industry as it becomes available.  

The PCDMN first took shape under the Integrated Crop Agronomy Cluster (2018-2023) and is funded through the Canadian Agricultural Partnership. The Cluster is led by the Western Grains Research Foundation in partnership with the Saskatchewan Canola Development Commission, Alberta Wheat Commission, Saskatchewan Wheat Development Commission, Alberta Pulse Growers, Saskatchewan Pulse Growers, Manitoba Pulse and Soybean Growers, Manitoba Wheat and Barley Growers Association, and Agriculture and Agri-Food Canada.  Read more on our "About Us" page.

This week:

• We update the 2020 Weekly Cereal Rust Risk Reports by releasing Report 9 for June 30-July 6, 2020.
• We ask users to please use these instructions to subscribe to the PCDMN Blog in order to receive all our disease updates in your Inbox! 

2020 Cereal Rust Risk Report (Jun 30-Jul 06)

Since 2019, the Prairie Crop Disease Monitoring Network (PCDMN) has released a series of weekly Cereal Rust Risk Reports throughout May and June.  Read the OVERVIEW describing the collaborative nature of this effort and the methods employed.  Information related to trajectory events based on forecast and diagnostic wind fields and cereal rust risk is experimental, and is offered to the public for informational purposes only.


The latest wind trajectory cereal rust risk report is available for download now at the following link: June 30-July 6, 2020 report.  

As of July 6, 2020 the risk of stripe rust appearance from the Pacific Northwest (PNW) or from regional sources is low to moderate.  However, some Prairie locations may be at an increased stripe rust risk, especially where there were 3-6 reverse wind trajectory events from the PNW.  In addition, regional development of stripe rust continues to occur, especially in southern Alberta.  See this link for the latest map of Alberta locations where stripe rust has been observed as of July 9, 2020: July 9, 2020 AB stripe rust map.   

Given the appearance of stripe rust in four counties in southern Alberta, at Beaverlodge in the Country of Grande Prairie, and the first observations in the Saskatoon area of Saskatchewan, farmers in these regions should be on the look out for stripe rust in wheat.  Special focus should be on wheat fields seeded to varieties rated as susceptible or moderately susceptible. 


Access the ALL the full reports as downloadable PDF files by clicking the Cereal Rust Risk page.

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Stripe rust in 2020

As of July 2, 2020, there have been five reports of the initial appearance of stripe rust on Alberta winter wheat on June 5, 16, 19, and 30, 2020 in the Counties of Lethbridge, Cardston, and Forty-Mile in southern Alberta and in the County of Grande Prairie in the Peace Region of Alberta (except of Figure 2 taken from Cereal Rust Report Week 8).  On July 2, 2020 there was also an initial report of stripe rust in the Saskatoon region (R. Kutcher, personal communication).  Given the appearance of stripe rust, farmers in these regions should be on the look out for stripe rust in wheat.  Special focus should be on wheat fields seeded to varieties rated as susceptible or moderately susceptible.

Figure 2. Reported observations of stripe rust in Alberta as of June 30, 2020 (indicated by yellow highlighted areas). Reports are courtesy of: 1) Lethbridge County, Dr. Reem Aboukhaddour, AAFC Lethbridge, June 5, 2020 (https://twitter.com/ReemWheat/status/1269109731337142274); 2) Lethbridge County, Agronomist Lyle Jensen from June 16, 2020 (https://twitter.com/LyleJensen6/status/1272925759183577088); 3) County of Grande Prairie, personal communications on June 19, 2020 from Jeremy Hodges and Henry Klein-Gebbinck, AAFC Beaverlodge, Beaverlodge, Alberta; 4) Cardston County, personal communication, June 30, 2020, Mike Harding, AAF Brooks; and 5) Foremost area of the County of Forty-Mile, personal communication from Joal McCordick, Syngenta, southern Alberta, via M. Harding, AAF Brooks, June 30, 2020.

Read the full Cereal Rust Report for Week 8 (June 22-29, 2020).
Follow @PCDMN for updates.