Weekly Update

Jennifer Otani, Ross Weiss, David Giffen, Serge Trudel, Kelly Turkington, Erl Svendsen, Owen Olfert and Meghan Vankosky
Categories
Week 11

Greetings!

Another busy week of in-field monitoring, data collection, and field tour events for all our Staff!  A reminder that, from now until mid-July, the Weekly Update may need to be posted in multiple segments (i.e., at any point from Wednesday-Saturday).  Please bookmark the Blog or subscribe to receive the latest growing season information!

This week, special thanks to Ross Weiss (AAFC-Saskatoon) – entomologist and the integral modeler who works to generate all the weekly wind trajectory, meteorological, and predictive model updates supporting the Prairie Pest Monitoring Network. 

Please access the complete Weekly Update either as a series of Posts for Week 12 (June 27, 2019) OR a downloadable PDF. Be sure to check out the Insect of the Week – the rest of the growing season features doppelgangers to aid in-field scouting!

Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Meghan Vankosky or Jennifer Otani.  Past “Weekly Updates” can be accessed on our Weekly Update page.

Subscribe to the Blog by following these easy steps!

Weather synopsis

Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 11

Temperatures this week, June 11-17 2019, were similar to last week and near normal (Fig. 1). The warmest temperatures were observed across AB while temperatures were cooler in eastern SK and across MB.  Average 30-day temperatures were warmest across southern MB and SK from Estevan to Saskatoon and west to Kindersley (Fig. 2). Cooler temperatures were reported across the Parkland region, and western areas in AB (Fig. 2). 

Figure 1. Average temperature (°C) across the Canadian prairies the past seven days (June 11-17, 2019).
Figure 2. Average temperature (°C) across the Canadian prairies for the month of May (May 19-June 17, 2019).

Seven-day cumulative rainfall indicated that minimal rain was observed across most of the prairies (Fig. 3). Many locations reported less than 10 mm.  Higher rainfall amounts were reported for eastern SK and western MB. 

Figure 3. Cumulative precipitation observed the past seven days across the Canadian prairies (June 11-17, 2019).

Across the prairies, rainfall amounts for the past 30 days (May 19 – June 17, 2019; Fig. 4) have been approximately 56 % of normal (Fig. 5). Western SK and eastern AB continue to be dry. 

Figure 4. Cumulative precipitation observed the past 30 days across the Canadian prairies (May 19-June 17, 2019).
Figure 5. Percent of Average precipitation across the Canadian prairies for the past 30 days (to June 17, 2019).  
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (18Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

Growing season rainfall (April 1 – June 17) amounts have been well below average for most of the prairies, particularly in west central SK and eastern regions of AB (Fig. 6). Almost all of the prairies has had growing season rainfall that is 4 percent, or less, than average. Soil moisture values are low across most of the prairies. 

Figure 6. Accumulated precipitation (mm) across the Canadian prairies for the growing season (April 1 to June 17, 2019).  
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (18Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The growing degree day map (GDD) (Base 5 ºC, April 1-June 17, 2019) is below (Fig. 7):

Figure 7. Growing degree day (Base 5 ºC) across the Canadian prairies for the growing season (April 1-June 17 2019).  
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (13Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The growing degree day map (GDD) (Base 10 ºC, April 1-June 17, 2019) is below (Fig. 8):

Figure 8. Growing degree day (Base 10 ºC) across the Canadian prairies for the growing season (April 1-June 17, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (18Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The lowest temperatures (°C) observed the past seven days ranged from about 8 to -2 °C in the map below (Fig. 9).

Figure 9. Lowest temperatures (°C) observed across the Canadian prairies the past seven days (to June 17, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (18Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The highest temperatures (°C) observed the past seven days ranged from about 18 to at least 31 °C in the map below (Fig. 10).

Figure 10. Highest temperatures (°C) observed across the Canadian prairies the past seven days (to June 17, 2019).
Image has not been reproduced in affiliation with, or with the endorsement of the Government of Canada and was retrieved (18Jun2019).  Access the full map at http://www.agr.gc.ca/DW-GS/current-actuelles.jspx?lang=eng&jsEnabled=true

The maps above are all produced by Agriculture and Agri-Food Canada.  Growers can bookmark the AAFC Drought Watch Maps for the growing season.

Monarch migration

Jennifer Otani
Categories
Week 11

We continue to track the migration of the Monarch butterflies as they move north by checking the 2019 Monarch Migration Map!  A screen shot of the map has been placed below as an example (retrieved 18Jun2019) but follow the hyperlink to check the interactive map.  They are moving west in Manitoba and getting closer to Saskatchewan this week!

Access this Post to help you differentiate between Monarchs and Painted Lady Butterflies!

Visit the Journey North website to learn more about migration events in North America and visit their monarch butterfly website for more information related to this amazing insect.  

Weekly Update

Jennifer Otani, Ross Weiss, David Giffen, Serge Trudel, Kelly Turkington, Erl Svendsen, Amanda Jorgensen, Owen Olfert and Meghan Vankosky
Categories
Week 11

Hello!

Our field research programs are now in full field research mode with in-field monitoring, data collection, and field tour events.  This means that, from now until mid-July, the Weekly Update may need to be posted in multiple segments (i.e., at any point from Wednesday-Saturday).  Please bookmark the Blog or subscribe to receive the latest growing season information!

Please access the complete Weekly Update either as a series of Posts for Week 11 (June 20, 2019) OR a downloadable PDF. Be sure to check out the Insect of the Week – the rest of the growing season features doppelgangers to aid in-field scouting!

Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Meghan Vankosky or Jennifer Otani.  Past “Weekly Updates” can be accessed on our Weekly Update page.

Subscribe to the Blog by following these easy steps!

Field Events – Speak to an entomologist

Jennifer Otani
Categories
Week 11

Public summer field events – Coming to a field near you –  Prairie field crop entomologists are already scheduled to be at these 2019 field tour events from May-August (be sure to re-confirm dates and details as events are finalized):

•  June 20, 2019: Solstice Forage and Crops Field Tour to be held at the Beaverlodge Research Farm (Beaverlodge AB).  View event info/registration details Entomologists tentatively participating: Jennifer Otani, Keith Uloth


•  June 26, 2019: 2019 CanolaPALOOZA to be held at the Lacombe Research and Development Centre (Lacombe AB).  View event info/registration details.  Entomologists tentatively participating: Jennifer Otani, Amanda Jorgensen, Meghan Vankosky, Scott Meers, Shelley Barkley, Patty Reid, Sunil Shivananjappa, Hector Carcamo, Julie Soroka, Mark Cutts, Jim Tansey, Sherrie Benson and the Junior Entomologists.

•  July 9-12, July 16-18, 2019: Crop Diagnostic School. Held at the University of Manitoba Research Farm at Carman, Manitoba. An 2-week diagnostic school will complete units on entomology, plant pathology, weed science, soil fertility, pulse crop production, and oilseed production. View registration and event information. Entomologists participating: John Gavloski and Jordan Bannerman.

•  July 9, 2019: CanolaPALOOZA Saskatoon, to be held at the SRDC Llewellyn Farm. Read more about this event.  Entomologists presenting: Tyler Wist, James Tansey, Greg Sekulic, Meghan Vankosky

•  July 22, 2019: Pulse grower gathering held near Three Hills AB.  Check Alberta Pulse Growers Event Page for more information.  Entomologists presenting: Graduate students from Dr. Maya Evenden’s (U of A) working on pea leaf weevil.

•  July 23-24, 2019: Crop Diagnostic School, Scott Saskatchewan. Read more about this event.  Entomologists presenting: Meghan Vankosky, Tyler Wist.

•  July 24, 2019: Crops-a-Palooza. Held at Canada-Manitoba Crop Diversification Centre (CMCDC), Carberry, Manitoba. Read more about this event. Entomologist participating: John Gavloski, Vincent Hervet, Tharshi Nagalingam, Bryan Cassone.

•  August 8, 2019:  2019 Wheatstalk to be held at Teepee Creek AB.  View event info/registration details.   Entomologists tentatively participating: Jennifer Otani, Amanda Jorgensen, Boyd Mori.

  August 8, 2019. Horticulture School. Agriculture and Agri-Food Canada Research Farm, Portage la Prairie, Manitoba. View event info/registration details.  Entomologist presenting: John Gavloski, Kyle Bobiwash.

Provincial Insect Pest Reports

James Tansey, John Gavloski and Scott Meers
Categories
Week 11

Provincial entomologists provide insect pest updates throughout the growing season so we link to their most recent information: 

Manitoba‘s Insect and Disease Updates for 2019 are posted here and includes an update posted June 5, 2019.

Saskatchewan‘s Crops Blog Posts includes a segment on “Early season scouting of cutworms” by Sara Doerksen posted in April 2019 and “Economic thresholds” by Kaeley Kindrachuk posted in May 2019. Also access the Crop Production News with Issues #1, #2, and #3 now available and containing insect pest information for 2019.

•  Alberta Agriculture and Forestry’s Call of the Land regularly includes insect pest updates from Mr. Scott Meers. The most recent Call of the Land was posted March 18-22, 2019 but did not include an insect update.

Crop report links

Jennifer Otani
Categories
Week 11

Crop reports are produced by:

The following crop reports are also available:

Previous Posts

Jennifer Otani
Categories
Week 11

Click to review these earlier 2019 Posts:

2019 Risk and forecast maps – Week 2

Alfalfa weevil – Week 10

Bertha armyworm – Week 10

Cabbage seedpod weevil – Week 10
Cereal aphid APP – Week 10
Cereal leaf beetle – Week 9
Crop protection guides – Week 6
Cutworms – Week 5

Field heroes – Week 6
Flea beetles – Week 5

Grasshoppers – Week 10

Insect scouting chart for Canola – Week 5
Insect scouting chart for Flax – Week 5

Painted lady butterfly – Week 8
Pea leaf weevil – Week 10

Ticks and Lyme disease – Week 4

Weather Radar – Week 6
Wildfires – Week 8

Wind trajectories – Review Page for list of PDFs

Predicted grasshopper development

Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 11

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).

Across the prairies, the grasshopper hatch is well underway this week with most locations having approximately 51% hatch (30% last week). Based on model runs, (i) approximately 30% (21% last week) of the population is in the first instar, (ii) 14.5% (7% last week) is predicted to be in the second instar, and (iii) 4.3% (1% last week) in the third instar.   

Figure 1.  Predicted development stages of grasshopper (Melanoplus sanguinipes) populations across the Canadian prairies (as of June 17, 2019). 

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba AgricultureSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is available as a free downloadable document in either an English-enhanced or French-enhanced version.

Alfalfa weevil

Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 11

Alfalfa Weevil (Hypera postica) – Degree-day maps of base 9°C are produced using the Harcourt/North Dakota models (Soroka et al. 2015).  Models predicting the development of Alfalfa weevil (AAW) across the prairies are updated weekly to help growers time their in-field scouting for second-instar larvae. 

Alfalfa weevil larval populations are developing into later instars (Fig. 1). Second instar development is nearing completion and this week there larvae should be in the third instar stage. This week larvae are mostly second (26%, 52% last week) and third instars (52%, 22% last week; Fig. 1). Model output indicates that fourth instar larvae are beginning to occur in southern SK and isolated areas in southern AB and MB.

Figure 1. Predicted average instar stage of alfalfa weevil (Hypera postica)  populations across the Canadian prairies as of June 17, 2019. 

The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.  

Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).  Additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (Philip et al. 2015). The guide is available in both a free English-enhanced or French-enhanced version.

Predicted bertha armyworm development

Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 11

Bertha armyworm (Lepidoptera: Mamestra configurata– Pupal development is progressing and this week adults should be occurring across most of southern SK and localized areas in AB.  Most of the population is predicted to be in the pupal stage (89%). The BAW model indicates that 10% of the population is in the adult stage .

Figure 1. Predicted precent of bertha armyworm (Mamestra configurata)  populations at adults stage across the Canadian prairies as of June 17, 2019. 

Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta and the Prairie Pest Monitoring Network. Also refer to the bertha armyworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” which is a free downloadable document as both an English-enhanced or French-enhanced version.

Again, thanks to John Gavloski (Manitoba Agriculture) who helped update the PPMN Bertha armyworm monitoring protocol.  Use the images below (Fig. 2) to help identify moths from the by-catch that will be retained in phermone-baited unitraps.

Figure 2. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D).
Photos: J. Williams (Agriculture and Agri-Food Canada)

Also be sure to review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!

Predicted wheat midge development

Ross Weiss, David Giffen, Owen Olfert and Meghan Vankosky
Categories
Week 11

Wheat Midge (Sitodiplosis mosellana) – Wheat midge adults generally emerge during the first week of July. Compared to long term normal values for temperature and rainfall, May and June in the Saskatoon region has been approximately 1 °C cooler and rainfall is 40-60% less than normal. Dry conditions in May and June can have significant impact on midge emergence. Elliott et al (2009) reported that wheat midge emergence was delayed or erratic, if rainfall did not exceed  20-30 mm  during May.  

Olfert et al. 2016 ran model simulations to demonstrate how rainfall impacts wheat midge population density. Two simulations were run to demonstrate the impact of rainfall and temperature on adult emergence and oviposition. The first graph illustrates adult emergence and oviposition based on long term (climate) data for Saskatoon (Fig. 1). The model indicates that emergence should begin in early July with oviposition beginning a few days later. 

Figure 1. Predicted adult emergence and oviposition of wheat midge (Sitodiplosis mosellana) based on LONG TERM DATA for Saskatoon SK.

The second graph (Fig. 2) shows how DRYER, COOLER conditions would result in:

  • Delayed adult emergence and oviposition.
  •  Reduced numbers of adults and eggs.
Figure 2. Predicted adult emergence and oviposition of wheat midge (Sitodiplosis mosellana) using LONG TERM DATA manipulated to both DRYER and COOLER conditions for Saskatoon SK.

Monitoring:
When monitoring wheat fields, pay attention to the synchrony between flying midge and anthesis.

  • In-field monitoring for wheat midge should be carried out in the evening (preferably after 8:30 pm or later) when the female midges are most active. 
  • On warm (at least 15ºC), calm evenings, the midge can be observed in the field, laying their eggs on the wheat heads (Fig. 3). 
  • Midge populations can be estimated by counting the number of adults present on 4 or 5 wheat heads. 
  • Inspect the field daily in at least 3 or 4 locations during the evening.
Figure 3. Adult wheat midge (Sitodoplosis mosellana) active on wheat head at anthesis stage
(Photo: AAFC-Beaverlodge; S. Dufton and A. Jorgensen).

REMEMBER in-field counts of wheat midge per head remain the basis of economic threshold decision.  Also remember the parasitoid, Macroglenes penetrans (Fig. 4), is actively searching for wheat midge at the same time. Preserve this parasitoid whenever possible and remember your insecticide control options for wheat midge also kill beneficial insects that help regulate midge populations.

Figure 4. The tiny parasitoid wasp, Macroglenes penetrans, is synchronized to emerge when wheat midge adults are present and the wasp seeks and oviposits on wheat midge eggs (Photo: AAFC-Beaverlodge; S. Dufton).

Economic Thresholds for Wheat Midge:

a) To maintain optimum grade: 1 adult midge per 8 to 10 wheat heads during the susceptible stage.

b) For yield only: 1 adult midge per 4 to 5 heads. At this level of infestation, wheat yields will be reduced by approximately 15% if the midge is not controlled.

Inspect the developing kernels for the presence of larvae and the larval damage. 

Information related to wheat midge biology and monitoring can be accessed by linking to your provincial fact sheet (Saskatchewan AgricultureAlberta Agriculture & Forestry) or access the Prairie Pest Monitoring Network’s monitoring protocol recently updated by Wist et al. 2019.  A review of wheat midge on the Canadian prairies was published by Elliott, Olfert, and Hartley in 2011.  

Alberta Agriculture and Forestry has also released a YouTube video describing in-field monitoring for wheat midge this week.  

More information about Wheat midge can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View ONLY the Wheat midge pages but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

Cabbage seedpod weevil

Jennifer Otani
Categories
Week 11

Cabbage seedpod weevil (Ceutorhynchus obstrictus) –  There is one generation of CSPW per year and the overwintering stage is the adult which is an ash-grey weevil measuring 3-4mm long (Refer to lower left photo).  Adults typically overwinter in soil beneath leaf litter within shelter belts and roadside ditches.

Monitoring:

  • Begin sampling when the crop first enters the bud stage and continue through the flowering. 
  • Sweep-net samples should be taken at ten locations within the field with ten 180° sweeps per location.  
  • Count the number of weevils at each location. Samples should be taken in the field perimeter as well as throughout the field.  
  • Adults will invade fields from the margins and if infestations are high in the borders, application of an insecticide to the field margins may be effective in reducing the population to levels below which economic injury will occur.  
  • An insecticide application is recommended when three to four weevils per sweep are collected and has been shown to be the most effective when canola is in the 10 to 20% bloom stage (2-4 days after flowering starts). 
  • Consider making insecticide applications late in the day to reduce the impact on pollinators.  Whenever possible, provide advanced warning of intended insecticide applications to commercial beekeepers operating in the vicinity to help protect foraging pollinators.  
  • High numbers of adults in the fall may indicate the potential for economic infestations the following spring.

Damage: Adult feeding damage to buds is more evident in dry years when canola is unable to compensate for bud loss.  Adults mate following a pollen meal then the female will deposit a single egg through the wall of a developing pod or adjacent to a developing seed within the pod (refer to lower right photo).  Eggs are oval and an opaque white, each measuring ~1mm long.  Typically a single egg is laid per pod although, when CSPW densities are high, two or more eggs may be laid per pod.

There are four larval instar stages of the CSPW and each stage is white and grub-like in appearance ranging up to 5-6mm in length (refer to lower left photo).  The first instar larva feeds on the cuticle on the outside of the pod while the second instar larva bores into the pod, feeding on the developing seeds.  A single larva consumes about 5 canola seeds.  The mature larva chews a small, circular exit hole from which it drops to the soil surface and pupation takes place in the soil within an earthen cell.  Approximately 10 days later, the new adult emerges to feed on maturing canola pods.  Later in the season these new adults migrate to overwintering sites beyond the field.

Albertan growers can report and check the online map for CSPW posted by Alberta Agriculture and Forestry (screenshot provided below for reference; retrieved 02Jul2019).

Please find additional detailed information for CSPW in fact sheets posted by Alberta Agriculture and ForestrySaskatchewan Agriculture, or the Prairie Pest Monitoring Network.

Insect of the Week – Doppelgangers: Wheat midge vs. Lauxanid

Amanda Jorgensen
Categories
Week 11

The case of the innocuous versus the evil twin: When making pest management decisions, be sure that the suspect is actually a pest. This can be challenge since insects often mimic each other or look very similar. An insect that looks, moves and acts like a pest may in fact be a look-alike or doppelganger. 

Doppelgangers may be related (e.g. same genus) or may not be related, as in the case of monarch butterflies (Danaus plexippus) and viceroys (Limenitis achrippus). Doppelgangers are  usually relatively harmless but sometimes the doppelganger is a pest yet their behaviour, lifecycle or hosts may be different. 

Correctly identifying a pest enables selection of the most accurate scouting or monitoring protocol. Identification and monitoring enables the application of economic thresholds. It also enables a producer to select and apply the most effective control option(s) including method and timing of application.  For the rest of the growing season, the Insect of the Week will feature insect crop pests and their doppelgangers.

The case of the wheat midge vs. Lauxanid fly:Wheat midge larvae, in high enough numbers, can significantly reduce yield and quality of a wheat crop. The time to control this pest is at the adult stage. The key to determining whether adult numbers exceed the economic threshold for control is to follow the recommended insect pest monitoring protocol.

One hiccup is that it can be easy to mistake lauxanid flies for wheat midge adults when doing in-field scouting. But their size, general body shape and colour differences will help enable a person to tell them apart.

Wheat midge:

  • Thinner “mosquito-like” body (Image 1, left)        
  • Long, thin legs
  • Between 1.5- 2 mm long        
  • Dark, vibrant orange when alive        
  • Large, black eyes that proportionally make up approximately 9/10’s of head

Lauxanid fly:

  • Bulkier body (Image 1, right)        
  • Shorter, compact legs   
  • Between 2 and 4 mm long        
  • Paler, less vibrant orange colour        
  • Smaller eyes that may be black, brown or red. Eyes proportionally make up approximately ½ of head
Image  1: Wheat midge (left) and Lauxanid (right).
Photo Credit: Bob Elliott (ret.), AAFC

Wheat midge larvae (Image 2) will feed on developing wheat kernels and can be found inside the wheat head. Lauxaniid larvae are not recorded as pests of any field crop and tend to be found in decaying leaf litter. Wheat midge larvae can be identified by their bright orange colour, and presence of spatula structure (Fig. 2; y-shaped structure circled below).

Image 2: Wheat midge larvae
Photo credit: AAFC-Jorgensen
Image 3: Wheat midge laying eggs on wheat head.
Photo credit: AAFC-Dufton

More information on wheat midge, other crop pests and their natural enemies, is available by accessing the updated Field Crop and Forage Pests and their Natural enemies in Western Canada field guide. Also refer to https://MidgeTolerantWheat.ca for the latest information on fighting wheat midge using tolerant wheat varieties.

Review previously featured insects by visiting the Insect of the Week page.

Post contributed by Amanda Jorgensen.

Wind Trajectories

Ross Weiss, Serge Trudel, David Giffen and Meghan Vankosky
Categories
Week 11

Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s.

In a continuing effort to produce timely information, the wind trajectory reports are available in two forms:

Prairie Crop Disease Monitoring Network

Kelly Turkington and prairiepest_admin
Categories
Week 11

The Prairie Crop Disease Monitoring Network (PCDMN) represents the combined effort of our prairie pathologists who work together to support in-field disease management in field crops.  

In 2019, the PCDMN will release a series of weekly Cereal Rust Risk Reports throughout May and June.  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. 

Background:  Agriculture and AgriFood Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s. Trajectory models are used to deliver an early-warning system for the origin and destination of migratory invasive species, such as diamondback moth. In addition, plant pathologists have shown that trajectories can assist with the prediction of plant disease infestations and are also beginning to utilize these same data. An introduction will be presented of efforts to identify wind trajectory events that may bring rust urediniospores into Western Canada from epidemic areas in the central and Pacific northwest (PNW) regions of the USA. Identification of potential events as well as an assessment of epidemic severity from source locations, and prairie weather conditions, will be used to assess the need for prompt targeted crop scouting for at-risk regions of the Canadian Prairies.

Two documents are available from the PCDMN:

Summary of wind trajectory and cereal rust risk assessment and the need for in-crop scouting in the Prairie region, June 11-17, 2019:

1. Pacific Northwest – Currently there is limited stripe rust development in the PNW, a low number of recent wind trajectories from the PNW, and relatively dry Prairie weather conditions, while winter wheat is progressing into heading and beyond, and spring wheat is moving into the stem elongation stage.  Thus, as of June 17, 2019, the risk of stripe rust appearance from the PNW is relatively low and scouting for this disease is not urgent.

2. Texas-Oklahoma corridor – In general, crops are advancing towards maturity, while in many areas of Texas harvesting has been completed, and thus winter wheat crops in these areas will become less of a source of rust inoculum.  There has been a limited number of recent wind trajectories from this area, relatively dry Prairie weather conditions, while winter wheat is progressing into heading and beyond, and spring wheat is moving into the stem elongation stage.  Thus, as of June 17, 2019, the risk of leaf and stripe rust appearance from the Texas-Oklahoma corridor is low and scouting for these diseases is not urgent.  

3. Kansas-Nebraska corridor – Leaf and stripe rust development in winter wheat continues in Kansas, although the winter crop is starting to turn colour in many regions.  Although rusts have only been recently reported in Nebraska, levels are on the rise, and thus over the next few weeks this region could act as a significant source of rust inoculum for the Prairie region.  From June 11-17, 2019 there has been a low number of wind trajectories from this area.  In general, weather conditions have been relatively dry across the Prairies, while winter wheat is progressing into heading and beyond, and spring wheat is moving into the stem elongation stage.  Thus, as of June 17, 2019, the risk of leaf and stripe rust appearance from the Kansas-Nebraska corridor is relatively low and scouting for these diseases is not urgent; however, further development of rust Nebraska may increase the risk.  

4. Where farmers or consultants noticed stripe rust development on winter wheat in the fall of 2018 it is recommended to scout winter wheat fields this spring.  Scouting is especially critical where the variety being grown is susceptible to stripe rust.  Currently, there are no reports of stripe rust in commercial fields of winter or spring wheat across the Prairie region.

5.  Access the full downloadable report.


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