Weekly Update (UPDATED!)

Jennifer Otani, Owen Olfert, Ross Weiss, Erl Svendsen and David Giffen
Week 16


Three sections of the Weekly Update for Week 16 (August 17, 2016) were just updated!  A downloadable PDF copy of the updated Weekly Update can now be accessed here.  

Subscribe to the Blog by following the instructions posted here!  You can receive automatic updates in your inbox through the growing season.

Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Owen Olfert or Jennifer Otani.  Past “Weekly Updates” are very kindly archived to the Western Forum website by webmaster, Dr. Kelly Turkington.  

Weekly Update – Weather Synopsis (updated)

Ross Weiss, Owen Olfert, David Giffen and Erl Svendsen
Week 16

Weather synopsis – The average temperature over the past seven days (August 7-14, 2016) was similar to Long Term Normal (LTN) values.

Across central Alberta, Saskatchewan, and Manitoba,  average cumulative rainfall was well above LTN values.

The average 30 day temperature for July 8-August 7, 2016, was similar to LTN and rainfall was 50% greater than LTN (average across the prairies). The wettest conditions have been in south and central areas of western Saskatchewan and central Alberta.

The average growing season temperature (April 1- August 7, 2016) was marginally warmer than normal. Growing season rainfall has been approximately 28% above average.

The map below shows the modelled soil moisture across the prairies (August 14, 2016).

The updated growing degree day map (GDD) (Base 5ºC, March 1 – August 14, 2016) is below:

While the growing degree day map (GDD) (Base 10ºC, March 1 – August 14, 2016) is below:

The map below shows the Lowest Temperatures the Past 7 Days (August 10 – August 16, 2016) across the prairies:

The map below shows the Highest Temperatures the Past 7 Days (August 10 – August 16, 2016):

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

Weekly Update – Swede midge (updated)

Julie Soroka, Ross Weiss, Owen Olfert and prairiepest_admin
Week 16

Swede midge (Contarinia nasturtiiThis growing season, bioclimatic model outputs predicting swede midge development continue to be compared to in-field observations of actual midge in canola in Saskatchewan since the model has yet to be validated with midge data from that region.

The model was run for Melfort SK for April 1 – 14 and the output suggests 4 generations might possibly occur in 2016 in northeast Saskatchewan.

Warm, wet conditions are predicted to result in shorter generation times in July and August than May and June.

In-field monitoring continues to be the priority both to detect new populations of swede midge on the prairies but then to validate the number of generations and phenology of this pest relative to canola development on the prairies.    

Swede midge scouting tips for in-field monitoring:

• Watch for unusual plant structures and plant discolourations then follow-up by closely scrutinizing the plant for larvae.
• The growing tip may become distorted and produce several growing tips or none at all, young leaves may become swollen, crinkled or crumpled and brown scarring caused by larval feeding may be seen on the leaf petioles and stems.
• Flowers may fail to open.
• Young plants that show unusual growth habits should be examined carefully for damage and larvae; especially if the sticky liners have many flies resembling midges (swede midges are about the size of orange blossom wheat midge but are not orange).
• Larvae can be seen with a hand lens.
• Refer to the Canola Watch article by Dr. Julie Soroka for more information on swede midge and watch for a new Ontario fact sheet produced by Baute et al. 2016.

Weekly Update – Grasshoppers (Updated)

Ross Weiss, Owen Olfert, David Giffen and Erl Svendsen
Week 16

Grasshoppers (Acrididae) – Across the prairies the model indicates that 80% of the population should be in the adult stage. This is approximately 10% greater than average. Oviposition is predicted to be well underway and is most advanced in Manitoba and southeast Saskatchewan.  

In central Saskatchewan, grasshopper development is slightly ahead of average development. The following graph shows predicted grasshopper development at Saskatoon for August 7, 2016. The model indicates that oviposition is well underway.  

Melanopline development for Saskatoon (August 12, 2016) was 5.6. The most abundant species was M. dawsoni (40%), followed by M. bivittatus (21.6%).

Biological and monitoring information related to grasshoppers in field crops is posted by the provinces of ManitobaSaskatchewanAlbertaBritish Columbia and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.

Weekly Update

Jennifer Otani, Owen Olfert, Ross Weiss, Erl Svendsen and David Giffen
Week 16


A downloadable PDF version of the complete Weekly Update for Week 16 (August 17, 2016) can be accessed here.  

This edition includes the “Insect of the Week” featuring beneficial arthropods in 2016!

Subscribe to the Blog by following the instructions posted here!  You can receive automatic updates in your inbox through the growing season.

Questions or problems accessing the contents of this Weekly Update?  Please e-mail either Dr. Owen Olfert or Jennifer Otani.  Past “Weekly Updates” are very kindly archived to the Western Forum website by webmaster, Dr. Kelly Turkington.  

Weekly Update – Pre-Harvest Intervals (PHI)

Jennifer Otani
Week 16

Pre-Harvest Interval (PHI) -Reminder – Growers with late-season insect pest problems will need to remember to factor in the PHI which is the minimum number of days between a pesticide application and swathing or straight combining of a crop.  

The PHI recommends sufficient time for a pesticide to break down and a PHI-value is both crop- and pesticide-specific.  Adhering to the PHI is important for a number of health-related reasons but also because Canada’s export customers strictly regulate and test for the presence of trace residues of pesticides.

An excellent summary of PHI for various pesticides in their various crops was posted by Saskatchewan Agriculture this week within their Crop Production News.

In 2013, the Canola Council of Canada created and circulated their “Spray to Swath Interval Calculator” which was intended to help canola growers accurately estimate their PHI.  Other PHI are described in your provincial crop protection guides and remember that specific crop x pesticide combinations will mean different PHIs.  More information about PHI and Maximum Residue Limits (MRL) is available on the Canola Council of Canada’s website.

Weekly Update – West Nile Virus and Culex tarsalis

David Giffen, Owen Olfert and prairiepest_admin
Week 16

West Nile Virus Risk –  The regions most advanced in degree-day accumulations for Culex tarsalis, the vector for West Nile Virus, are shown in the map below.  As of August 14, 2016areas highlighted in yellow, orange, or red on the map below have accumulated sufficient heat for C. tarsalis to fly so wear your DEET to stay protected!

The Public Health Agency of Canada posts information related to West Nile Virus in Canada.  The map of clinical cases of West Nile Virus in Canada in 2016 is posted (as of July 23, 2016) while a screen shot is provided below (retrieved August 17, 2016).

WN Cases Canada.jpg

The Canadian Wildlife Health Cooperative compiles and posts information related to their disease surveillance for West Nile Virus.  As of August 17, 2016, 32 birds were submitted for testing yet none have tested positive for West Nile virus. 

Provincial Insect Pest Reports

John Gavloski, Scott Meers, Scott Hartley and prairiepest_admin
Week 16

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

Manitoba’s Insect and Disease Update which includes lygus in canola, notes the occurance of small insect larvae on sclerotinia-infected areas of canola, soybean and dry beans AND includes a call for grasshopper surveying in August (August 17, 2016, prepared by John Gavloski and Pratisara Bajracharya).

Saskatchewan’s Crop Production News includes an update on West Nile disease in Saskatchewan in Issue 7prepared by Scott Hartley.  The report notes, “For the week of August 6, 2016, Saskatchewan Health reported that numbers of Culex tarsalis continue to rise in southern and central Saskatchewan. The risk of West Nile Virus transmission to humans remains at a moderate level in southern Saskatchewan, but increasing numbers of infected mosquitoes have been found this past week.”

Watch for Alberta Agriculture and Forestry’s Call of the Land for updates from Scott Meers who recently provided an update (posted on August 4, 2016). The most recent Call of the Land (posted August 17, 2016) features Cam Dahl who described issues associated with pre-harvest application of pesticides.

Weekly Update – Crop reports

Scott Meers, Scott Hartley, John Gavloski and prairiepest_admin
Week 16

Crop reports are produced by:

– Manitoba Agriculture, Rural Development (August 8, 2016).

– Saskatchewan Agriculture Crop Report (August 8, 2016) which is also posted in a printer-friendly version.

– Alberta Agriculture and Forestry (for August 2, 2016).

The USDA publishes a Crop Production Report (Posted August 12, 2016) and a Crop Progress Report (posted August 15, 2016) which includes harvest and condition ratings for winter wheat, spring wheat, oat, barley, plus range and pasture conditions. 

The USDA also produces a World Agricultural Production Report (July 2016) which estimates production across the globe for corn, cotton, rapeseed, and wheat but also includes tabular data for other grains.

Weekly Update – Previous Posts

Jennifer Otani
Week 16

The following is a list of previous 2016 Posts – click to review:

Alfalfa weevil

Aphids in canola 

Bertha armyworm development and flight
Bertha armyworm

Cabbage root maggot
Cabbage seedpod weevil
Canola scouting chart
Cereal leaf beetle
Crop protection guides

Diamondback moth

Environment Canada’s radar maps to follow precipitation events

Flea beetles in canola

Iceburg reports
Insects in our diet

Monarch migration

Pea leaf weevil monitoring

Predicted lygus bug development
Predicted wheat midge development

Swede midge

Thrips in canola

Weather Synopsis (Week 12)

Wheat midge
Wind trajectories

Weekly Update – Harvest Sample Program

Jennifer Otani
Week 16

The Canadian Grain Commission is ready and willing to grade grain samples harvested in 2016.  Samples are accepted up to November but send samples as soon a harvest is complete.

This is a FREE opportunity for growers to gain unofficial insight into the quality of their grain and to obtain valuable dockage information and details associated with damage or quality issues.  The data collected also helps Canada market its grain to the world!

More information on the Harvest Sample Program is available at the Canadian Grain Commission’s website where growers can register online to receive a kit to submit their grain.  

In exchange for your samples, the CGC assesses and provides the following unofficial results FOR FREE:
  • dockage assessment on canola
  • unofficial grade
  • protein content on barley, beans, chick peas, lentils, oats, peas and wheat
  • oil, protein and chlorophyll content for canola
  • oil and protein content and iodine value for flaxseed
  • oil and protein for mustard seed and soybeans
Many producers find having both grade and quality information on their samples before delivering their grain to be helpful.

Insect of the Week – Assassin bug

Jennifer Otani
Week 16
year, the focus of the Beneficial 
Insect of the Week was crop pests. This year, we’re changing things up and
highlighting the many natural enemies that help you out, silently and
efficiently killing off crop pests. [note: featured Insects of the Week in
2015 are available on the
 Insect of the Week page]
week’s feature beneficial insect is the Assassin Bug. I love it when a common
name is so apt. Assassins (at least in the movies) are guns for hire and
they’ll take out whoever is on their list. They’re usually the bad guys but on
occasion can be a force for good (e.g.
Jason Bourne). Similarly
in the insect world, assassin bugs are indiscriminate in who they attack,
preying on immature and adult forms of beneficials and pests alike by patiently
lying in wait for their target to come within stabbing distance.
more information about these natural enemies, other pests they control and
other important crop and forage insects, see the new Field Crop and
Forage Pests and their Natural Enemies in Western Canada – Identification
and Management Field Guide for identification, life cycle and conservation
options (download links for field guide available on the 
Insect of the Week page).

Assassin bug (Reduvius personatus), Keith Roragen, Flickr