Blog: Agronomy & Extension

Manitoba Farmers Participate in 2023 NSA Sunflower Survey

In alternate years, the National Sunflower Association performs a sunflower survey in six states (ND, SD, MN, CO, KS and NE). The survey looks at several agronomic pests and pressures and the potential yield impacts in the given year. In 2023, Manitoba Crop Alliance (MCA) participated in the survey with the help of Ahmed Abdelmagid, research scientist for oilseed crops pathology at Agriculture and Agri-Food Canada’s (AAFC) Morden Research and Development Centre. Nine sunflower fields were surveyed in Manitoba, reflecting the approximately 85,000 total sunflower acres in 2023.

This project serves two purposes:

  1. Identifying factors that affected yield in the given year and which may be of increasing importance in the future, and
  2. Identifying potential research priorities.

Factors that were looked at specifically during the survey were the following:

  • Yield components – plant population, head diameter, seed size, % good seed, % centre seed set, bird damage
  • Agronomic information – crop type, row width, tillage practices
  • Weed Assessment
  • Diseases
  • Insect & bird damage

Fields were visited in mid- to late-September, once R9 was reached and each was surveyed at two different sites within the field. Of the nine Manitoba locations, six were oilseed production fields and the remaining three were confections, and all locations were distributed throughout southern Manitoba from Eastman to Westman areas.

The initial process in each sampling location was to do a plant count followed by another count including only “harvestable” plants (this would not include very small heads, heads with no seed, lodged plants). These harvestable plants were used in yield estimation against all the factors that lay ahead. Head diameter was measured in inches on five plants per location and centre seed set was measured (diameter of seed not set in the centre of each head). Next, seed samples were taken from three heads and stored in a paper bag to send for testing, but not before determining percentage good seed (% filled seed) and seed size.

A general assessment of the field was made at each sample location for yield limiting factors (birds, disease, insects, weeds, drought, uneven plant growth, hail, herbicide damage, lodging and plant spacing within the row) and the top two limiting factors were ranked. The most common limiting factor across the nine surveyed fields was disease (five fields) and the remaining four fields had greatest limiting factor being birds, drought, lodging or weed pressure. It was rare to find a second limiting factor in these fields, which had a positive impact on yield due to less pressure on the crop.

Bird damage was estimated in the percentage of seeds lost. Five fields had bird damage at the time of surveying, ranging from 0.5 – 4.5 per cent seed loss. Surveying is typically done around the same time blackbirds tend to begin feeding on sunflowers and one of these surveyed fields had a significant increase in bird damage by harvest.

Insect presence measurements accounted for sunflower midge, sunflower seed maggot, sunflower bud moth and long-horned beetle damage (not found in Manitoba). 25 heads at each field site were examined for the above insect damage, aside from long-horned beetle, which required stalk splitting to identify the larvae presence.

Sunflower midge damage. Photo credit: National Sunflower Association.
Sunflower midge damage. Photo credit: National Sunflower Association.
Sunflower seed maggot damage. Photo credit: NDSU.
Sunflower seed maggot damage. Photo credit: NDSU.
Sunflower bud moth damage. Photo credit: NDSU.
Sunflower bud moth damage. Photo credit: NDSU.


Disease observations and samples were taken of the following, when present:

  • Root lodging
  • Midstalk lodging            
  • Ground level lodging    
  • Sclerotinia wilt (basal stem)
  • Sclerotinia mid-stalk rot
  • Sclerotinia head rot
  • Rhizopus head rot
  • Downy mildew
  • Phomopsis stem canker
  • Phoma black stem
  • Verticillium wilt/leaf mottle
  • Charcoal rot
  • Rust

Lodged plants were identified, on average, at the nine locations as follows:

  • Root lodging or percent root upheaval – 2 per cent
  • Ground level lodging – 1.5 per cent
  • Mid stalk lodging – <1 per cent

Sclerotinia infections were significant, but averaged across all nine locations, the per cent instances are quite insignificant:

  • Sclerotinia wilt (basal stem) – 4 per cent
  • Sclerotinia mid-stalk rot – 3 per cent
  • Sclerotinia head rot – 6 per cent

Other diseases were more significant in 2023 and this likely reflects most years, but stem rots tend to go more unnoticed unless lodging is a major issue. Rhizopus head rot was found in two locations, but samples are being tested for disease presence. Rhizopus is not a disease Manitoba sunflower farmers have had to deal with in the past, so further testing is being pursued to determine if this is a misdiagnosis or a real issue. Downy mildew and charcoal rot were not found in any of the sample sites. Verticillum wilt was found to be present on 2 per cent of surveyed plants and rust remained low with roughly 6 per cent infection area on leaves.

Phomopsis and phoma were the real diseases of concern in surveyed fields, which reflects the prior mention of disease being the most yield limiting factor in 56 per cent of surveyed locations. According to final yields, neither disease seemed to impact yield noticeably and lodging due to stalk disease did not occur. Phomopsis stem canker was found in 10 per cent and phoma black stem in 8 per cent of plants surveyed with diseased stalk samples being taken for further analysis. Phoma had very high incidence (80 per cent) across the entire survey in Manitoba and the six states, meaning 80 per cent of all plants sampled had phoma infections. Phomopsis was lower, at 34 per cent incidence in all samples, however this was noted to be an increase from past surveys. It is thought that Phomopsis stem canker prevalence increased due to any of the following factors:

  • Susceptible hybrid
  • Drought stress or other factors
  • No fungicide use
  • Wet weather closer to harvest

Weeds were generally not a concern in fields surveyed except for one that had lambs quarters and Canada thistle escapes and heavy pressure. It was this field that was identified as having weed presence being the primary contributor to any yield loss that was incurred.

MCA has applied for partial funding through the provincial government Sustainable Canadian Agricultural Partnership call for funding for the sunflower disease survey for 2024-27. During this time, they will be partnering with Agriculture and Agri-Food Canada to do disease verification of samples collected from the 2023 and 2025 season. This partnership allows further collaboration and cooperation with our NDSU partners to participate in their survey, bringing our members a larger dataset, with more information on disease tends.

Corn Establishment in Dry Soil Conditions

“Corn roots will not grow into dry soils.” – Dr. Joe Lauer, professor of plant and agroecosystems sciences, University of Wisconsin-Madison (retired)

When Manitoba experiences a dry cycle, a major concern is the ability of our crops to endure very dry and crusting soils. Spring drought is particularly concerning for crop germination and emergence. Without moisture, germination simply will not occur. With limited moisture, germination may begin and become halted if/when moisture runs out, resulting in an unproductive seed(ling).

According to Joel Ransom, North Dakota State University small grains & corn extension agronomist, “For most soils, 0.5 inches of rain (sandy soils require slightly less) is needed in order for moisture to move to a two-inch depth (the seed zone) in dry soils. Poor seed-soil contact can restrict the corn seed from extracting enough moisture from the soil to germinate. Crop residues that touch the seed can similarly impede the movement of water to the seed. Occasionally, fertilizers placed with the seed inhibit germination due to their salt effect being more pronounced in dry soils1.”

Of course, soil moisture is not just required for germination. It is required for all vegetative and reproductive growth. Nodal root development is occurring as the growing seedling reaches V1 staging and this requires ample moisture in the top two inches of soil. This new root development will be the primary means by which the plant acquires water and nutrients by the V3 stage1, so successful nodal roots are critical for further development. If soil is to remain dry around the crown (where nodal roots develop, about 0.75 inches below soil surface) for extended periods during early vegetative growth, these nodal roots will not develop. As corn plants grow larger, they become too heavy without the support of this root system and will flop over. This is where the terms floppy or rootless corn syndrome come from and these have frequently been found in areas of higher compaction or shallow seeding in recent years but will be a common symptom of dry growing seasons.

Figure 1: First set of nodal roots developing on a V1 Corn Seedling. Photo: Dr. Bob Neilsen, Purdue University.

Weather conditions in the entire month of May are impossible to predict. It is extremely rare to have so little soil moisture that the crop is unable to germinate or that the crop runs out of moisture during early development. It is rare that this should occur and to the best of our knowledge, it has not happened in Manitoba on a large scale.

Should a crop failure occur in spring due to dry conditions and young seedlings die off via dehydration, a replanting scenario may be considered. Stand reduction does have to be very significant to justify replanting corn simply because of the delayed planting date. Manitoba Agricultural Services Corporation (MASC) historical data shows that there is an estimated yield loss of 5% per week delay in spring planting.

Figure 2: Average relative yield reported to MASC during each sowing week for the selected crops grown in Manitoba for the period of 2010-2019.

Replanting corn is a very expensive decision and most often is not economical unless stand loss is over 16,000 plants per acre. Even in that scenario, the farmer may still be looking at too significant a loss to make it worthwhile. Replanting grain corn should only ever be considered after careful economic analysis of costs against any potential gain2.

For more information on growing corn on the Prairies, see Corn Production Resources on our website.


  1. Ransom, Joel. “Dry Soils and Poor Corn Emergence.” NDSU Crop & Pest Report, NDSU, 1 June 2017,
  2. Manitoba Agriculture, Corn Seed Bed Preparation. 

Seeding Flax to Provide the Best Start

Typically, flax is seeded from May 1st to June 20th. It may be seeded the last out of all the crops as the bolls and seeds can stand and ripen in the fall without shelling while other crops like canola are being harvested. Prolonged exposure to fall weather, though, will reduce the quality of the harvested seed and make it ineligible for a food grade market. MASC data has shown that flax has good yield potential in the last week of May (Table 1), but yields decline in some areas as the calendar turns to June. MASC seeding deadline is June 20th for all of Manitoba.

Table 2: Relative Stubble Yield Response (2011 – 2020). Source: Manitoba Agricultural Services Corporation.

Yield response data from MASC, recorded from 2011 – 2020 (10 year results), shows that flax responds best when seeded following a pea crop, with the next best response after corn (Table 2). It generally has the poorest yield response when seeded following any oilseed crop, for obvious reasons. Research has shown that flax performs poorly specifically after canola and/or mustard, and not only because of disease issues. The poorer performance of flax on canola stubble is attributed to mycorrhizae fungi which do not associate strongly with canola and decrease in presence during the canola crop’s growing season. When flax is grown on canola stubble, the mycorrhizae populations are lower, which leads to poorer early  season nutrient update, especially phosphorus, a relatively immobile nutrient in the soil that is crucial to early flax development.

Flax does well after cereals or corn. It also performs well after legume crops and alfalfa, but Rhizoctonia disease may be a problem. Flax does not do well after potatoes due to the loose seedbed and potentially Rhizoctonia in this rotation as well. According to MASC, the most common crop stubble that flax is seeded into is spring wheat in Manitoba and very few acres are seeded into pea stubble, so that flax-on-pea yield data in Table 2 could be seen as skewed. Crop rotation is extremely important when making all cropping decisions, but flax is a particularly sensitive plant to many outside factors and rotation should be paid considerably close attention to. It is recommended to have at least three years between flax crops on a field to control various soil-borne or stubble-borne diseases of flax, such as pasmo.

Table 2: Relative Stubble Yield Response (2011 – 2020). Source: Manitoba Agricultural Services Corporation.

For a successful flax crop, the greatest strategy is to enable the crop to emerge in a uniform and dense plant stand. This helps the crop with weed control throughout the season and allows for consistent physiological maturity down the road.

Tips for a productive flax plant stand:

  • Target ½ to ¾ inch seeding depth to allow crop to emerge quickly
  • Do not overfertilize. Flax does not respond positively to increased rates of fertilizer. Excess nitrogen will cause prolonged maturity and potential lodging issues.
  • Target a higher seeding rate. Flax depends very heavily on adequate stand establishment and plant populations of 40 – 56 plants/ft2. Typical emergence for flax is 50% – 60% of seeding rate. Seeding rates on the high end of the recommended range should be used for ground prone to crusting when seeding late or under heavy weed pressure.
  • Do not seed flax on poorly drained soils or sandy soils because of poor water retention. Medium to heavy-textured soils are preferable. These soils may also crust in the spring, which can inhibit flax emergence.

For more information on growing flax on the Prairies, see Flax Production Resources on our website.

MCA-funded research at the 2023 Manitoba Agronomists’ Conference

On Dec. 13 and 14, 2023, Manitoba agronomists met to discuss the latest developments in pest, crop and soil management. This year, the conference theme was “Advanced Technologies: tools or replacements for agronomists?” Much of the research shared at the Manitoba Agronomists’ Conference was funded in part by Manitoba Crop Alliance (MCA).

The following is a summary of the posters shared that featured MCA-funded research:

Soil Fertility

  • Performance of Soybean-based Rotations in Manitoba: Soil P and K
    Ramona Mohr, Yong Min Kim, Mohammad Khakbazan, Debbie McLaren (ret’d), and Byron Irvine (ret’d), Agriculture and Agri-Food Canada

Crop Management

  • Leveraging On-Farm Research to Evaluate New Malting Barley Varieties for Production and Malting Selection in Manitoba
    Li Yueshu, Canadian Malting Barley Technical Centre, Ashley Ammeter, Morgan Cott, Daryl Rex, Andrew Hector, Manitoba Crop Alliance
  • Performance of Soybean-based Rotations in Manitoba: Yield and Quality
    Ramona Mohr, Yong Min Kim, Mohammad Khakbazan, Debbie McLaren (ret’d), Byron Irvine (ret’d), Agriculture and Agri-Food Canada
  • Establishment of Annual Crop-Living Mulch System
    Jessica Frey, Joanne Thiessen Martens, University of Manitoba

Pest Management

  • Performance of Soybean-based Rotations in Manitoba: Root Diseases
    Yong Min Kim, Debbie McLaren (ret’d), Ramona Mohr, Byron Irvine (ret’d), Mohammad Khakbazan, Agriculture and Agri-Food Canada
  • Are Intercropped Cover Crops Compatible with Canola Weed Management on the Canadian Prairies?
    Janelle Gawiak, Yvonne Lawley, University of Manitoba, Maryse Bourgault, University of Saskatchewan, Linda Gorim, University of Alberta
  • Manitoba Survey of Herbicide-resistant Weeds in 2022
    Charles Geddes, Mattea Pittman, Agriculture and Agri-Food Canada, Kim Brown-Livingston, Manitoba Agriculture, Julie Leeson, Agriculture and Agri-Food Canada

During the crop management session, Amy Delaquis also presented her research on Agronomic Management to Maximize Spring Wheat Yield and Protein while Minimizing Lodging Risk. Check out our factsheets that summarize this research:

For a full list of poster presentations and speakers from the 2023 conference, as well as a recording of the 2023 presentations (available February 2024), visit the Manitoba Agronomists’ Conference website.

Thank you to the conference partners – University of Manitoba, Manitoba Agriculture and the Prairie Certified Crop Advisor Board – for hosting an excellent conference!

Research on the Farm: Sunflower Plant Population Trials Summarized (2021 – 2023)

Manitoba Crop Alliance’s Research on the Farm program looks at common agronomic, crop-specific concerns on field-scale, replicated trials in commercial fields. 2023 saw the sunflower plant population trials completed with 21 site-years of data.

The objective of this specific trial was to quantify the agronomic and economic impacts of various plant populations on both oilseed and confectionary sunflower production in Manitoba. Constant genetic improvements in sunflower hybrids raise the question of whether farmers can either increase or decrease their planting populations with improvements in quality and/or yield. Farmers took to the field to make that final decision.

Figure 1: MCA Research on the Farm Sunflower Plant Population Trial locations, 2021 – 2023.

Tone Ag Consulting performs MCA’s Research on the Farm trials in all 6 of our crop-types. In this specific trial type, they are helping the farmer with planting and harvest of the plots, plus taking some key information during the growing season. This includes soil sampling in the spring followed by growth stage notes and precipitation data during the season.

Table 1: Three-year summary of sunflower plant population trial for 21 site years. Six site-years contributed statistically significant yield differences which would provide profit for the farm, based only on seed prices.

When looking at this full data set, it doesn’t necessarily give a farmer the details they are looking for. At the end of the day, they want to know the ROI for each treatment, which includes spring seed costs and sunflower prices off the combine. Simply stated, if the “high” planting rate outyielded the “low” and “check” planting rates, it may have only been marginally, therefore the higher seed cost of planting at a high rate was likely not the economical choice.

Table 2: Three-year economic summary of sunflower plant population trial for 21 site years. Net profit per acre was calculated using estimated seed cost in spring 2023 and contract pricing in fall 2023.

Sunflower farmers tend to be aware of the best management practices for their farm, which is evident in Table 2, above. Planting populations are reasonably simple to set up on-farm and MCA recommends farmers make the effort to periodically do this same testing. 2022 and 2023 were dry years in areas of Manitoba, which may have skewed results, but it is important to continue to collect data in years of varying precipitation to determine planting rates that work better on your farm in all environments.

New-to-flax chemistry now registered for in-crop use

It has long been known that flax farmers need stronger weed control options to successfully grow and maintain good quality and higher-yielding flax crops. BASF has been a strong supporter of flax in recent years, encouraging the growth of acres on the Prairies. In 2022, BASF announced a new registration for Heat ® LQ applied as a pre-harvest treatment aid on flax, which both MCA and SaskFlax partnered in running a field trial program for testing.

As of early November 2023, BASF announced that Armezon® herbicide is now registered for post-emergent applications to flax. This use was registered under the User Requested Minor Use Label Expansion program. Armezon® herbicide is a Group 27, post-emergent herbicide that is quickly absorbed by leaves, roots, and shoots to quickly control target weeds. The herbicide claims control of common ragweed, Eastern black nightshade, kochia (less than 10 cm), redroot pigweed, volunteer canola (prior to 6-leaf stage) and wild mustard, when applied at the recommended rate and with a specific adjuvant partner.

Manitoba flax farmers are very fortunate to have this ongoing support and can look forward to an additional tool in their toolbox to aid in successfully keeping their flax crops cleaner in 2024.

Further details on Armezon® herbicide registration in flax can be found in the accompanying documents.

Project Update: MCA Development of Long-Type Confection Sunflower Hybrids

Each year, Manitoba Crop Alliance (MCA) releases the Sunflower Variety Performance Trial (VPT) data for both oil and confection sunflowers. In recent years, several confection experimental lines have been tested under the company, MCA. It is reassuring to the future of the sunflower industry in Manitoba that several seed companies continue to invest in the success of this crop.

In 2011, the National Sunflower Association of Canada (NSAC), now amalgamated under MCA, joined the impressive list of organizations that are investing in variety development to bring improved sunflower hybrids to our farmer members. Manitoba has a strikingly short list of available confection hybrids and those that are available are not new genetics. There is also an absence of herbicide-tolerant hybrids with improved disease packages that would benefit confection sunflower farmers.

This is a very exciting time for MCA. As a project that started many years ago with NSAC and has remained a high priority in MCA’s research program, it is very possible that one of these lines will be registered soon, with strong interest from the sunflower industry. MCA is very proud of our breeder’s hard work and commitment to building these three strong experimental hybrids that have strong yields and promising genetic and agronomic packages for Manitoba’s unique growing conditions.

MCA sunflower breeder, Mike Hagen, standing in the first commercial field to test MCA experimental hybrids.

MCA is looking for confection sunflower farmers to conduct strip trials in their 2024 commercial sunflower fields. Interested farmer members can contact Daryl Rex, research trial specialist at MCA, for more information.

MCA’s Elite Sunflower Hybrid Guide


This project supports Manitoba Crop Alliance’s farmer-led hybrid confection sunflower breeding program. Hybrids with herbicide and disease resistance, suitable for Canadian growing conditions will be developed as part of this project.

Project Objectives

  1. Develop elite parent lines, possessing genes for tolerance to sulfonylurea herbicide, rust and downy mildew.
  2. Produce testing seed, test and isolate confection sunflower hybrids for Canadian production that are high yielding, lodging resistance with improved dark, long-type seed. Resistant to sulfonylurea herbicide, rust and downy mildew.

Flax Diseases: A 2023 Overview

Pasmo is the primary disease of concern in flax in Manitoba and has a regular seat at the table. Severity ranges from year to year and depends on how early symptoms start to show, but it can have significant effects on yield.

The fungus is both residue- and seed-borne, so best management practices include crop rotation, using clean seed, seeding early and fungicide use, which relies heavily on ideal timing. Keeping fields weed-free is another management practice that also benefits yields via disease prevention. Keeping inter-rows clean enables drying winds to pass through the crop easily and deter fungi or bacteria from setting, but also gets rid of other disease hosts that could enable infection of the crop.

Manitoba Crop Alliance, in partnership with SaskFlax, performs an annual flax disease survey on representative acres in Manitoba. It was uncharacteristically dry in Manitoba in 2023, which led industry members to believe disease pressure would likely be quite low across most crops and mundane disease surveys were to follow.

Pasmo and Aster Yellows were the main diseases of interests this year, but it isn’t yet known how they impacted yield. Pasmo ranged in incidence in-field from 0 – 42 per cent, with severity being as high as 75 per cent in the hardest-hit flax crops. Some flax crops were fortunate to have zero incidence of the disease, most likely due to thinner stands and drier conditions during the season.

Pasmo-infected flax stalk.

Aster Yellows were not significant, but in fields that were affected, it was easy to spot the damage and yield will have been impacted in diseased patches. This is a very random disease, infecting plants that have been fed on by aster leafhoppers that are specifically infected by the aster yellow phytoplasma. Aster yellows affect many different crops, with canola being the most economically significant in Manitoba. Aster leafhoppers are sucking insects that transmit aster yellow phytoplasma directly into the phloem of a healthy flax plant, thereby infecting that plant. Damage is evident in misshapen or unproductive bolls.

Flax aster yellows.

In preparation for the 2024 flax crop, farmers will want to follow some key tips for disease prevention:

  • Use clean seed
  • Diversify crop rotation
  • Use seed treatments
  • Keep fields weed-free

For more information on growing flax on the Prairies, see Flax Production Resources on our website.

Corn Facts: Drought and Harvest 2023

Drought conditions seriously threatened the 2023 grain corn crop in Manitoba. From planting until mid-September, many local fields remained depleted of adequate moisture to support good corn growth and development. As harvest occurs, it is easy to see where the drought impacted yields the most and where crops were graced with timely rains and have succeeded in yielding well.

The following are some facts that help tell the story of 2023 and why some fields were affected more than others:

  • Nodal root development and functionality is reliant on soil moisture. At a shallow depth of 0.75 inches, if soil moisture is not available, the roots cannot properly establish, extract soil water or nutrients, or support upright growth of the corn plant.
  • Corn leaves roll and appear pineapple- or onion-like in response to heat and drought. This decreases the surface area exposed to sunlight and reduces transpiration. Unfortunately, it also reduces photosynthetic activity in the plant, which impacts both maturity and yield.
  • Kernel rows per ear have been said to be determined by V6. Number of rows is determined more by genetics than by environment.
  • Kernels per row are determined from about V7 to a week prior to silking. This development is vulnerable to environmental stresses.

Figure 1. Corn water demand by growth stage.
Credit: Golden Harvest Seeds.

  • Drought stress has a major impact during the V13 to silking (R1) stages of corn development. Water demand is at its peak during this time, so drought and heat stress negatively impact reproduction. 
  • Silks initiate elongation from the kernels around seven days prior to silking. Drought stress can slow elongation, delaying silk emergence or even causing failure of silks to emerge from the husk. Successful emergence of silks is then threatened by moisture and heat stress, which may desiccate silks and make them unviable to pollen shed.
  • Adversely, drought stress speeds up pollen shed. Silk emergence and pollen shed may not sync, which means pollination potential is not met.
  • Water demand remains high during the remainder of the reproductive stages and is required for proper grain development and fill.
  • Drought stress can affect a corn plant’s ability to fill grain properly. As the plant begins to shut down and senesce, it is moving all its sugars and reserves to the grain to fill to its maximum. This process may be cut off by environmental factors, commonly including a severe frost.
  • Prolonged environmental stress will lead to premature physiological maturity. The lack of moisture tells the plant to go into survival mode and fill grain with its remaining energy and reserves (mentioned above). This enables the plant to shut down from the ground up and eventually reach R6 (physiological maturity). The grain begins to dry down from this point on.
  • Stalk diseases may be present, regardless of drought conditions during the growing season. Harvest affected fields first to avoid heavy winds and lodging losses.

Gibberella stalk rot on corn stalk.
Credit: Pioneer.

  • Ear moulds may be present, regardless of drought conditions during the growing season. Harvest affected fields first to avoid spread of disease on cobs and quality concerns.

Fusarium Ear Mould.


The value and importance of seed testing

If you are planning on saving seed for next year’s crop, seed testing should be considered, as weather conditions from the year the seed was grown, such as precipitation and heat, affect seed quality. Seed testing in the fall can provide growers with useful information that can save them both time and money – allowing them to plan for next year’s growing season with greater certainty.

Typically, seed tests evaluate variables such as germination, thousand kernel weight, vigour and seed-borne diseases. Understanding these variables is important when making seeding management decisions, as seeds with poor germination and vigour or those that contain seed diseases can negatively impact crop establishment, uniformity and health. This will ultimately affect yield.

Information collected from seed tests is also integral to achieving your desired plant population, as thousand kernel weight should be used to determine optimal seeding rates. Additionally, understanding seed germination and vigour can give you a better gauge of expected seed survival and how the seed will perform in the spring.

Germination tests evaluate the percentage of seeds likely to develop or germinate under optimal moisture, light and temperature conditions. Vigour tests are similar but provide information regarding the ability for seeds to produce normal seedings in suboptimal conditions. Cold stress tests are often used to determine this, although there are multiple vigour testing protocols used by labs. Vigour testing is important, as seed vigour usually drops before the seeds ability to germinate does. More information about calculating seeding rates can be found here.

It’s important to note that long periods of storage can affect seed quality. For example, both germination and vigour levels can decrease during winter storage. Therefore, secondary seed testing in early spring may also be necessary. More information about seed testing and seed test interpretation can be found here.

The following labs conduct seed testing: