Flea Beetles – Chewing Their Way Into June

As many people find themselves finishing up the seeding season, we also find ourselves at the beginning stages of the bug season. If you have been out and about in your fields you have probably noticed small black bugs that are the size of a pin head bouncing around. 

The striped and crucifer flea beetles are the two common species that feed on canola in the Canadian prairies. Hop flea beetles can also be found, but occur in low numbers throughout the prairies. All three species can vary in the way they look, how they feed, and when they emerge. 

When To Look For Them

Flea beetles emerge in early Spring, and can cause damage to your canola crop from emergence, up until the 3-4 leaf stage. They aren’t picky eaters, and are known to feed on the cotyledons, leaves, stems, roots or any fleshy tissue on the plant. Sunny, warm and dry weather is preferred by the beetles, but less ideal conditions don’t seem to slow them down either. They are known to increase below ground and underside of leaf feeding during the less than ideal conditions.

How To Manage Them

It is important to assess where the bugs are feeding and how much of it there is. Action threshold levels are when average leaf area loss is more than 25%, and it is considered economically beneficial to spray insecticide when the leaf area loss is above 50%. There are no established threshold levels for stem feeding, which is why it is so important to assess where the feeding is taking place. If the flea beetles are actively feeding on leaf tissue, stem tissue and/or the growing point, the action level might be lower. 

There are different control options and management practices to help mitigate the damage these guys can have on your canola crop. Seed treatment options like Prosper Evergol and Helix Vibrance are standard on your canola seed to protect against flea beetles, but you can enhance your protection by adding Lumiderm on your seed when you order it. There are also in-crop insecticide control options to cover you off if populations rise and leaf damage is above threshold levels. Lastly, there are cultural control methods such as seeding early to get crop establishment before the emergence of the flea beetles, allowing a higher tolerance to injury. The second practice is increasing your seeding rate, this can help you reduce the impact of the flea beetle damage by spreading it out over more plants allowing for easier recovery from the stress event. 

Don’t Fear Though

The sight of these pesky little bugs probably have you wondering a few different things. Such as, why your seed treatment isn’t working. The truth is, it is working. But, with the newer chemistries, the flea beetles have to feed on the plant to ingest the insecticide for it to work. Whereas older seed treatments were used as more of a deterrent or repellent. Also, seed treatments only give a 28-35 day protection window after the crop is seeded, in cooler, dry weather the crop could be slower growing and not past the 3-4 leaf stage so it is at risk for flea beetle damage. 

Contact our SynergyAG Agronomists and they can help you determine which is the right course of action against your flea beetles! 


Niki Beingessner CCA, PAg

Sales Agronomist – Yorkton


Weeding Out The Weeds

Whether you are watching from the cab of a drill, floater, combine, or sprayer, this Spring you can see specks of green littering your fields that were unbelievably clean last year. This previous year was an anomaly on the Canadian prairies – A dry, cold Spring, where we had uneven germination, and weed-less fields for miles. Cue a timely rain in June, and that changed. Flushes of kochia, cleavers, and narrow-leaved hawksbeard took over our once clean crops. Fast forward to this year, we are seeing the repercussions of these flushes. Spring is a busy time, and a pre-burn is not always feasible, especially with the possibility of snow storms in April. Coming into post-emergence, we have to be prepared. 

Weeds such as kochia, volunteer canola, and wild buckwheat, although they look innocent, can prove to be detrimental to crop yields. High weed populations in the early part of the growing season create competition for water, nutrients, and sunlight, which are all essential for the developing crop. This is why it is important to have early control. A post-harvest application if possible, will reduce instances of winter annuals. A pre-emergence application will allow for a wide spectrum of herbicides to be used; in turn this doesn’t limit the weeds you can control. This will reduce stress on the plants and your sprayer operator, once the crop is emerged. 

Post-emergence, your options are limited a considerable amount. When this is the case, the best option is typically to wait until your crop reaches the appropriate staging for given herbicide options, and then spray. Given the way the growing season has started, our crops are going to have some early season vigour that we did not see in 2019. This means that it should have some competitive edge against weed pressure.

Another area we have advanced on in agriculture is herbicide rotation and herbicide layering. It is important to keep these in mind when spraying the crops, and when planning out your crop rotation. Herbicide rotation refers to using a different active on the same field with each pass. This is to ensure that weeds do not become herbicide resistant. An even more effective way to reduce herbicide resistance is to layer your active ingredients. This way, if one active only hurts the weed and doesn’t kill it, the next one will. This will limit the ability of the resistant plant to reproduce and make for a herbicide resistant mess in the following years. 

At the end of the day, your best option when it comes to weed control is to be proactive and to talk to your Agronomist. With them, you will want to discuss your options and the best way to control the spectrum of weeds in your field. Visit your local SynergyAG retail location and connect with their Agronomist.


Happy spraying!  

Karly Rumpel A.Ag., BSc.(Agr.)

Sales Agronomist

Synergy AG Govan




Maximum Residue Limits (MRLs): what they are and why they matter

Canada’s reputation for safe food is unparalleled, thanks to all the people involved in the food business, from field to fork. Although pesticides are an important part of our farming, nobody wants them remaining in or on food that we consume in quantities that can affect our health. That is why all food products grown in and imported into Canada (whether organic or conventionally grown) are tested for pesticide residue. As harvest progresses, it is important to keep maximum residue limits (MRLs) in mind.

What is MRL?

To put it simply, MRL is the highest level of a pesticide residue legally tolerated in or on food or feed. Relevant authorities set MRLs from multiple scientific trials that determine the maximum amount of residue that could remain on the crop when a pesticide is applied according to the product’s label instructions. Then, using estimates of how much a person might consume in a day or a year, risks are calculated. In Canada, MRLs are set by Health Canada for each pesticide and crop combination (Health Canada’s database of MRLs can be found here). MRLs are set at levels far below the amount of pesticide residue that could cause health concerns, taking into account all of the population including infants, children, and pregnant women. The Canadian Food Inspection Agency takes enforcement actions if tested food products exceed MRLs. MRL exceedance also has trade consequences.

What is our part?

As growers, we must continue to use good agricultural and pest management practices throughout the cropping season to keep residues within limits. This includes following label recommendations for rate and timing of application of agricultural chemicals, as well as proper storage of the harvested product. Pay particular attention to the pre-harvest interval recommended for whatever product you are using, whether desiccants or late-season fungicides or insecticides.

It is also important to keep an eye on recent developments in international markets. For example, because of the current heightened level of focus on glyphosate, there is a push in some markets for a reduction of its MRL or its ban as a pre-harvest aid in certain crops like oats. This trend may continue and emphasizes the importance of following label instructions to ensure Canadian products comply with MRLs set by buyers and importing countries.


-Ikenna Mbakwe, PhD, PAg
Head of Research



Blackleg of Canola: Importance of Late Season Scouting

Blackleg is one of the most serious diseases of canola, capable of causing significant yield losses of over 50% in susceptible fields. The more devastating form of the disease is caused by the fungus Leptosphaeria maculans. It overwinters on infected canola stubble and releases spores in the spring, which are then dispersed by wind and rain splash to newly planted canola crops. When plants are infected, the fungus grows within the plant’s vascular system causing a canker (lesion) that girdles the stem base, restricting water and nutrient flow within the plant and eventually causing the crop to lodge. Severe canker will sever the roots from the stem. The fungus may also attack pods and seeds.

Late season scouting

The most appropriate time to quantify the severity of blackleg infection in a crop is just before harvest. Scouting at this stage is necessary to ascertain whether a change in genetics and management is needed for the next season. A simple method is to clip 25 plants at the base of the stem/top of the root and look for blackened tissue inside the crown of the stem. Multiply the number of affected plants by 4 to get a percentage. If the incidence is over 30%, or if it has increased from the previous canola crop, then control strategies will have to be modified for the coming season. The Canola Council of Canada also provides a Blackleg Field Rating Scale (picture below) which rates each stem for percent discolouration caused by blackleg. A resistant variety should have a rating not worse than a “2”, otherwise that variety is no longer resistant to the blackleg races in that field.


The following strategies help to control and manage blackleg:

  • Use of resistant varieties is the best defence against blackleg. However, using the same resistant variety consistently in the same field increases the risk of certain races of the fungus overcoming the genetic resistance in that variety. So, it is important to rotate varieties.
  • Adopt a longer crop rotation (a 4-year rotation between canola crops is recommended) once blackleg has been detected in a field. An adequate crop rotation interval allows for the decomposition of infected canola residue, reduces disease pressure and prolongs the effectiveness of genetic resistance.
  • Use disease-free seed and treat seed from high-risk areas with fungicide. Note thatseed treatment will help prevent the spread of blackleg from infected seed to seedling, but will not protect the seedlings from infection by airborne spores.
  • Incorporate infected stubble after harvest.
  • Control volunteer canola and wild mustard in other crops.
  • A foliar fungicide can reduce symptoms of the disease and minimize yield loss if a susceptible variety is being grown.

Identifying and Controlling Bertha Armyworm


Bertha armyworm is one of the most destructive insect pests of crucifers in any year when there is a major outbreak. In Canada, it is found in Alberta, Saskatchewan, Manitoba, and some parts of British Columbia. Its preferred host plants include canola, rapeseed, mustard, and alfalfa, but it also attacks flax, peas and potato.

The adult stage is a grey-black moth with a silvery-whitish kidney-shaped marking on each forewing (picture below). A female moth can lay between 2,150 and 3500 eggs which hatch within a week. Newly hatched larvae are pale green and about 0.3 cm long but at maturity, larvae are about 4 cm long, with a light brown head and a yellowish-orange stripe along each side (picture below).  In late summer or early fall, larvae burrow into the ground where they survive the winter as pupae.

Bertha armyworm larva and adult. Photos courtesy of Government of Alberta

Crop damage

Crop damage is caused by the larval stage. The degree of damage will vary with the crop, the crop’s growth stage, and the number and growth stage of larvae present. Most crop damage usually occurs within three weeks between late July and late August. Larvae feed on the same plant where eggs were laid, however, mature larvae can move across fields in search of food. Larvae chew irregularly-shaped holes in leaves and can also feed directly on seed pods and seeds causing further crop loss due to premature shattering.



Regular monitoring of bertha armyworm larvae (weekly from the beginning of July) is critical for early detection and to minimize crop losses. Research has found an average loss in yield of 0.058 bushels/acre for each larva/m2. Chemical control will be economical when larval populations are enough to potentially cause a yield loss greater than the cost of controlling them. This will take into consideration the cost of the insecticide, the method of application and the value of the crop. Ask your SynergyAG rep for help with monitoring and controlling bertha armyworm.


-Ikenna Mbakwe, PhD, PAg
Head of Research



What to Consider When Desiccating Canola

What to Consider When Desiccating Canola

Harvest time is a critical stage in canola cultivation. Untimely harvesting and inappropriate harvesting techniques can reduce both yield and quality. If canola is straight cut, a desiccant can be applied to facilitate the harvest operation. As noted in the previous blog, desiccation is a useful way to accelerate dry down of the crop and minimize harvest problems such as uneven ripening and crop lodging.

Canola must be desiccated at the correct stage to avoid locking in green seed. If fields have variable stages, the stage that will contribute most to total yield should be determined. Canola seeds mature in the bottom pods first, while seeds in the top pods mature last.  When using diquat brands (e.g. Reglone Ion) application timing is after 90% of the seed on the entire plant has turned brown. Saflufenacil (Heat) has a labelled application rate of 60-75% brown seed, but recent recommendation is 80% brown seed. Applying desiccants earlier than recommended may result in higher green seed and reduced yields.

True desiccants are contact herbicides and rely heavily on penetration and canopy coverage. So higher water volumes and nozzles that provide good coverage maximize their performance. Note that If harvest is delayed following desiccation of canola, both pod drop and pod shatter may increase. So be prepared to combine as soon as seed moisture has reached suitable levels, which can happen in about 4 days, and no later than 14 days after application. Your SynergyAG rep will be happy to guide you every step of the way.


-Ikenna Mbakwe, PhD, PAg
Head of Research




Desiccation of Pulses

Desiccation of Pulses

Legumes (pulses) are more susceptible to weather damage than cereals, so a delay in harvesting can lead to loss of yield and deterioration of quality. To reduce the time from maturity to combining, field crops may be desiccated. Desiccation is the chemical termination of plant growth at the stage when all growth functions, seed size and yield have been set. It helps to minimize late disease development and harvest problems caused by late weed growth, uneven ripening of crops and crop lodging. It also makes for better control of harvest timing.

What are desiccants?

Desiccants are contact herbicides which are designed to quickly dry down the crop. They interfere with photosynthesis, causing plant cells to break down and release their liquid contents so they can dry down more rapidly than would have happened naturally. It is important to note that although glyphosate can desiccate a crop, it is not a true desiccant. It is a systemic herbicide which must be absorbed and translocated to growing points to kill plants, and therefore takes longer to dry the crop. Glyphosate is useful as a pre-harvest herbicide for weed control but when its application is incorrectly timed, there is a danger of herbicide residue ending up in the seed and exceeding maximum residue limits. Moreover, it should not be used on pulse crops destined for planting seed because of an increased risk of poor emergence.

When to apply desiccants

When applying desiccants, timing is important. Incorrect timing of pre-harvest herbicides can negatively affect crop maturity. Desiccants applied too early can interfere with the process of seed filling, resulting in yield loss. Research suggests that the best time to desiccate is when the seed has less than 30% moisture.

The decision to use a desiccant depends on the risk of the crop losing quality if left to dry down naturally in the field, and whether a producer needs to manage harvest workload and timing. Individual circumstances will determine if desiccation will provide financial and operational benefits. Your SynergyAG rep can guide you in making that call.

Keep an eye out for diamondback moth

The diamondback moth has the creepy reputation of being the most destructive insect pest of Brassica crops in various parts of the world. The insect attacks plants in the Brassicaceae family including canola, cabbage, mustard, broccoli, kale and cauliflower. It is estimated to cost the world economy US$4–5 billion annually and is particularly problematic in warm climates. In Canada, it does not overwinter well because of the long, cold winters, however, populations can be carried by strong winds from areas that allow year-round persistence (like southern United States and northern Mexico) into the Canadian Prairies in the spring. All stages of the insect can also arrive on contaminated seedlings.

The adult moth is gray and brown with a cream-colored band on its back that may be shaped like a diamond pattern when at rest (Figure 1). The insect is about 6 – 9 mm long, and has pronounced antennae.

Figure 1. Adult Diamondback moth. Photo by Roy Ellis (Canola Council of Canada)


Adult females can lay an average of 160 eggs on leaf surfaces during their short life span of about 16 days. Eggs hatch after 4-8 days. Most crop damage is caused by the larval stage. The larvae are pale yellowish-green to green caterpillars about 12 mm long (Figure 2).  Larvae feed on leaves, buds, flowers, seedpods, and sometimes, the developing seeds. When disturbed, the diamondback moth larva will wriggle backward violently and may drop from the plant, suspended by a silken thread. After a few seconds, it climbs back onto the leaf to continue feeding.

Figure 2. Diamondback moth larva (right) and pupa (left). Photo: Government of Manitoba


The Canola Council of Canada lists the following tips for best management:

  • Control brassicaceous weeds including volunteer canola.
  • Monitor provincial agricultural websites for early warning notices.
  • Early arrival = multi-generations = higher risk of economic damage.
  • Scout fields in July and August. Monitor crops at least twice per week.
  • Removing plants in an area measuring 0.1 m2(about 12″ square), beat them onto a clean surface, and count the number of larvae dislodged from the plants.
  • Consider insecticide application when 20 to 30 larvae/0.1 m2are present at the advanced pod stage. This works out to approximately two to three larvae/plant if plant population is close to 100 plants/m2).
  • Minimize impact on beneficial insects by using economic thresholds to ensure insecticide application is made only when warranted.


Be sure to talk with your SynergyAG rep for your scouting and product needs.



Tackling Fusarium Head-on

Recently, I sat at the edge of my seat, staring at my computer screen in shock as I read a BBC news story about how scientists are battling to save my favourite fruit from extinction. The Panama disease that threatened to wipe out bananas in the 1950s had made an aggressive comeback. This current outbreak was caused by a different strain of the same culprit, Fusarium. The news almost had me going bananas.

Although we do not produce bananas here in Western Canada, we are all very familiar with the problems caused by Fusarium. Fusarium is one of the most challenging groups of disease-causing fungi. Fusarium head blight (FHB), for example, is caused by several species of the fungus and affects cereals including wheat, barley, corn, rye, oats and some forage grasses. These fungi overwinter in the soil, on infected crop residue, and on seed. In the spring and summer, they release spores which are spread by rain-splash and wind to cereal heads during flowering. Infection is favoured by moist, humid conditions when temperatures are between 16 to 28 °C. Plants can also be infected through wounds caused by insects or birds. Spores that reach a cereal flower may infect the developing kernel. Visible symptoms appear within a few days after infection. Diseased spikelets show premature bleaching as the pathogen spreads within the head (picture below). Over time, the entire head may be affected.


A wheat spikelet showing symptoms of Fusarium head blight infection. Photo: University of Illinois

Fusarium head blight causes significant yield losses, and the fungus also produces mycotoxins that downgrade kernel quality and pose a major health threat to domestic animals and humans. An integrated approach is important for controlling its spread and mitigating risks. Some useful strategies include crop rotation, allowing sufficient time for crop residue to decompose, using fusarium-resistant varieties, using a good seed treatment, and applying appropriate fungicides at the start of flowering to suppress FHB. Your SynergyAG rep can guide you in being proactive against Fusarium.

-Ikenna Mbakwe, PhD, PAg
Head of Research

cabbage seedpod weevil

Fear no Weevil: 4 Things to Know About the Cabbage Seedpod Weevil

Number 1

The cabbage seedpod weevil (CSW) has been known as a crop pest since the beginning of the 19th century. But it was in 1931 that it was first recorded in North America – in British Columbia. From there it is believed to have moved south and east, and is now found throughout much of the United States. It was detected in southern Alberta in 1995 and since then has continued to disperse through the Prairies (2018 survey below).

Cabbage Seedpod Weevil Survey, 2018. Agriculture and Agri-food Canada

Number 2

Host plants belong to the mustard family (Brassicaceae) e.g. canola, brown mustard, cauliflower, cabbage, broccoli, wild mustard, stinkweed. Weevil population peaks when the host crop begins flowering.

Number 3

Adult CSW are gray, about 3 mm long, with a pronounced snout (pictures below). They overwinter beneath leaf litter where they burrow into the soil surface and are protected from low temperatures. In spring, they emerge from their overwintering habitats to search for host plants and feed on floral buds, seeds, nectar and racemes. Females lay eggs into developing pods which later hatch into larvae. Most crop damage happens when larvae feed within developing pods. Each larva can consume 3 to 6 seeds. But further yield loss can result when larvae create exit holes, which makes pods more susceptible to shattering. The feeding punctures and larval exit holes can also serve as entry points for other small insects and pathogens. Larvae drop from exit holes and pupate in the soil. The new generation adults emerge 9-30 days after exit from the pods depending on temperature.

cabbage seedpod weevil

Cabbage Seedpod Weevil. Photos by Niki Beingessner, SynergyAG, Lewvan.

Number 4

The key to protecting yield is to prevent adult CSW from laying eggs in newly formed pods. Regular monitoring of fields is vital. Populations can be monitored by taking sweep net samples (180-degree sweeps) beginning from when the crop first enters the bud stage and continuing through the flowering period. Chemical control is recommended when an average of two to four adult weevils are collected per sweep.

The cabbage seedpod weevil plays dead when disturbed. But don’t let that fool you. They’ll rise up after a few seconds to resume their destructive activities. Be sure to talk with your local SynergyAG rep about how to control this and other insect pests.

-Ikenna Mbakwe, PhD, PAg
Head of Research