Will I be able to improve the grade of my grain by using gravity tables and colour sorters?

Gravity tables and colour sorters have been shown to be an effective way of sorting out fusarium-damaged kernels (FDK) if the grower has the time and money to spend on the method. Gravity tables remove kernels based on density and are effective at removing heavily infected seeds, but can also result in the loss of healthy seed. Optical sorters remove kernels based on visual differences, but the process can be time-consuming and is more suited to hard wheat than soft wheat. Additionally, fusarium-damaged barley and oat do not show significant shrivelling and are not likely to be removed by equipment sorting by density, weight or colour.

It is important to remember that removing FDK (i.e. visibly infected kernels) from a grain sample does not mean that the grain is free of DON, the toxin produced by Fusarium graminearum. The relationship between FDK and DON varies and in years where infection occurs late in anthesis (or even after anthesis), visual symptoms are not always apparent whereas DON levels can still be elevated. While the Canadian Grain Commission grades wheat based on percent FDK, some markets are interested in DON levels. It is important to discuss with grain buyers and/or elevators their guidelines regarding FDK and DON. It is also recommended that growers test their grain for DON to best determine how to market it.

There is newer technology available that sorts grain based on chemical composition using near infrared transmission (NIR). This method is more effective at reducing DON levels because it is not only dependent on visual symptoms on the kernel. The machinery required to sort grain using NIR can be quite expensive to purchase, but is relatively inexpensive to run. For more information on this technology please refer to http://bomill.com/products/.

 

Submitted by

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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If I plan to sow Fusarium-infected seed, when should I use a seed treatment?

Using good quality seed, with high germinability and vigour, and low disease incidence, is always recommended. Cleaning of grain to remove fusarium damaged kernels can improve grade and seed germination. In addition, seed should be planted into warm, well-drained, fertile soil at the appropriate depth. Applying fungicidal seed treatments to cereal seed is also a beneficial management practice that helps reduce risks associated with seedling mortality and reductions in stand establishment due to seed-borne, seed-transmitted and soil-borne fungal pathogens especially when planting conditions are not optimal. Fusarium species are examples of fungi that can cause disease on germinating seeds and seedlings and reduce plant populations. The level of Fusarium infection in a seed lot should be determined by laboratory testing, not just by counting fusarium damaged kernels. In cases where Fusarium infections reduce germination, a germination test should be used to adjust the seeding rate so that emergence and yield are not compromised. Research has shown that when seeding rates are adjusted based on germination rates, seed with low levels of infection (5-10%) have no significant improvement in emergence or yield due to a seed treatment (May et al., 2010). However, it is important to keep in mind that other soil-borne, residue-borne or seed-borne microorganisms (i.e. pests other than Fusarium spp.) can also cause diseases on germinating seeds and seedlings, so even if Fusarium is not detected on seed, a seed treatment should still be considered as a beneficial risk management tool to protect against additional threats such as Pythium spp., Rhizoctonia spp., and others.

Seed treatment recommendations for each province are as follows:

Alberta

Threshold – 0%

Actions/Recommendations – Always use healthy seed with no detectable levels of F. graminearum

Always use a registered fungicidal seed treatment that includes Fusarium on the label

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex5210

Saskatchewan

Threshold – 2-3%

Actions/Recommendations – Use a seed treatment for F. graminearum infection in areas where F. graminearum is not established

Threshold – 5%

Actions/Recommendations -Do not use seed when F. graminearum infection levels exceed this threshold in areas where F. graminearum is not established

Threshold – 10%

Actions/Recommendations -Use a seed treatment when total Fusarium spp. infection levels exceed this threshold in areas where F. graminearum is established or when F. graminearum levels are less than 5% in areas where F. graminearum is not established

https://www.saskatchewan.ca/business/agriculture-natural-resources-and-industry/agribusiness-farmers-and-ranchers/crops-and-irrigation/crop-protection/disease/fusarium-head-blight

Manitoba

Threshold – none

Actions/Recommendations – Use clean seed with good germination, seed treatments may improve germination

http://www.gov.mb.ca/agriculture/crops/plant-diseases/print,dealing-with-fusarium-head-blight.html#field

REFERENCES

May, W. E., Fernandez, M. R. and Lafond, G. P. 2010. Effect of fungicidal seed treatments on the emergence, development, and grain yield of Fusarium graminearum-infected wheat and barley seed under field conditions. Can. J. Plant Sci. 90: 89 3_904.

Submitted by

Holly Derksen, Field Crop Pathologist

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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If I have grain or seed infected with Fusarium graminearum can I plant it?

In Alberta, any grain with detectable levels of F. graminearum cannot be used for seed because F. graminearum is a declared pest under Alberta’s Agricultural Pests Act. Section 22c of the Agricultural Pests Act states: “No person shall for propagation purposes acquire, sell, distribute or use any seed, root, tuber or other vegetable material containing a pest.”

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex5210

In Saskatchewan, F. graminearum is not a regulated pest. However, to reduce the spread of F. graminearum into areas where it is currently not established, seed containing more than 5% F. graminearum is not recommended to be used.

https://www.saskatchewan.ca/business/agriculture-natural-resources-and-industry/agribusiness-farmers-and-ranchers/crops-and-irrigation/crop-protection/disease/fusarium-head-blight

 In Manitoba, there are no restrictions or thresholds for planting F. graminearum-infected seed. However, grain should be tested for germination and Fusarium infection before determining its suitability for seed.

http://www.gov.mb.ca/agriculture/crops/plant-diseases/print,dealing-with-fusarium-head-blight.html#field

Submitted by

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture and Forestry

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Will storage of infected grain for over 1 year reduce Fusarium spp. infection and DON levels?

The viability of various Fusarium spp. during storage is dependent on the storage conditions, with temperature playing a key role. Scientific studies have demonstrated that Fusarium infection levels will be reduced when infected grain is stored for at least 6-9 months at a constant temperature of 25 °C and where either relative humidity is >62% or seed moisture content is at least 10-14%. One study demonstrated elimination of Fusarium graminearum when corn seed was stored in sealed containers at 30°C and a seed moisture content of 14%. However, the same is not true for infected grain stored at cooler temperatures (less than 15°C) which are more consistent with the recommendations for grain storage on the Canadian Prairies. At temperatures below 15C the viability of the pathogen (Fusarium spp.) is unchanged, unchanged, especially under drier conditions, making long term storage of infected grain a poor strategy for reducing Fusarium infection levels. Also, if the grain is to be used for seed, prolonged storage of infected grain at higher temperatures and moisture levels may result in reduced vigour and germination rates.

The mycotoxin deoxynivalenol (DON) in Fusarium infected grain is also unaffected by long-term storage, regardless of the temperature. Under safe storage conditions changes in DON levels would be unlikely.

Submitted by

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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If my grain has high levels of DON can I still use it for seed?

Deoxynivalenol (DON) is a mycotoxin produced by the fungus that causes fusarium head blight (FHB). The importance of determining DON levels in your harvested grain relates to the use of that product for human/animal consumption. DON is poisonous to humans so it is carefully monitored in grain used for food. Additionally, it is poisonous to livestock and can cause feed refusal and poor weight gain in livestock if present above recommended levels.

The relationships between fusarium-damaged kernels (FDK), seed infection by Fusarium spp., and DON levels are not consistent. Just because FHB was observed in the field and/or FDK were observed in a harvested sample it does not necessarily mean that DON is present. Conversely, the lack of these symptoms does not necessarily mean that DON is not present. The latter situation is often the case in years where conditions are conducive for Fusarium infection after anthesis. These DON levels are not accounted for when grading grain is based solely on the percentage of FDK.

While DON levels may affect the suitability of harvested grain as food or feed, seedling health and seed germination is affected by the extent of infection of seed by hyphae of Fusarium graminearum.  Thus, the level of infection by Fusarium spp., including F. graminearum, is a better measure of whether or not the grain should be used for seed in a subsequent season.

Recommendations:

For purposes of replanting, growers should have seed tested by an accredited lab for germination, vigour, and Fusarium infection levels. Based on this information growers can determine whether or not a grain sample is appropriate for planting (with or without a seed treatment) and whether the seeding rate would need to be adjusted. (See future questions in this series that will address whether or not to plant Fusarium-infected seed.)

For purposes of marketing and livestock feeding, growers should have grain tested for DON levels by an accredited lab. Grain companies and buyers are increasingly requesting information on DON levels as opposed to just FDK.

Submitted by:

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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Have a follow-up question?

Getting the Facts on Fusarium Head Blight

Fusarium head blight, or FHB, is a major disease that wheat and other cereal producers deal with each year to varying levels. The conditions in 2016 were conducive for infection in both winter and spring wheat as well as other cereal crops (symptoms were observed in both barley and oats). While 2016 was not the worse year on record for FHB in Manitoba (see post on FHB survey results), levels across the prairies were amongst the highest they have been in recent years.

Manitoba Agriculture has partnered with Alberta Agriculture and Forestry and the Saskatchewan Ministry of Agriculture to develop a Q & A series “Getting the Facts on Fusarium Head Blight”. This series will address FHB issues producers faced in the 2016 season as well as issues they are facing regarding infected seed. The answers provided will be a combined effort of the provincial disease specialists with input from researchers at Agriculture and Agri-Food Canada, the University of Saskatchewan, and the University of Manitoba.

If you have a question you would like to see addressed please submit via Crop Chatter or contact your provincial disease specialist.

Submitted by

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

Respond
Have a follow-up question?

2016 Manitoba Fusarium Head Blight Survey

The following are the results of spring and winter wheat fields surveyed for Fusarium head blight (FHB) by Manitoba Agriculture Staff. Fusarium head blight was observed in nearly every field surveyed (97% of winter wheat fields surveyed and 93% of spring wheat fields surveyed). The average FHB index for winter wheat in 2016 was 2.7% which was slightly below the 10-year-average (3.1%). The average FHB index for spring wheat in 2016 was 2.4% which was slightly above the 10-year-average (2.2%).

Winter wheat:

FHB was observed in 30/31 fields surveyed.

Region # Fields Surveyed Average Incidence Average Severity Average FHB Index
Central 13 18% 19% 3.6%
Eastern/Interlake 13 11% 16% 2.6%
Southwest 5 6% 11% 0.6%
MANITOBA 31 13% 16% 2.7%

*No winter wheat fields in the Northwest region were surveyed

Spring wheat:

FHB was observed in 50/54 fields surveyed.

Region # Fields Surveyed Average Incidence Average Severity Average FHB Index
Central 17 29% 12% 3.9%
Eastern/Interlake 17 8% 11% 1.1%
Northwest 10 7% 8% 0.7%
Southwest 10 23% 19% 3.9%
MANITOBA 54 17% 12% 2.4%

 

Submitted by Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

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Avoid Crop Injury – Recommendation for Sprayer Clean Out

Submitted by Jeanette Gaultier, MAFRD Pesticides Specialist

Crop injury caused by improperly cleaned sprayers accounted for 5 to 15 percent of total pesticide incidents reported to MAFRD over the past three years (see chart below). The acceptable number should be 0%, since injury caused by tank contamination is completely avoidable!

Picture1

Herbicides effective at low concentrations, such as group 2 herbicides, are the usual suspects. Improper clean out of group 14 herbicides, which also work at low concentrations and are increasing in use, are partly responsible for the 3X rise in tank contamination injury between 2012 and 2014. However, even low levels of other herbicide groups (e.g. group 4s) can cause injury to sensitive crops.

So, while cleaning is not the most fun job on the farm, it’s important (just like mom said). Follow these tips, from page 15 of the 2015 Guide to Field Crop Protection, to achieve a clean sprayer (www.gov.mb.ca/agriculture/crops/guides-and-publications/pubs/crop-protection-guide-intro.pdf):

  1. Clean your equipment as soon as possible after application. Sprayers should be cleaned at the end of an application, at the end of the day or when switching products (whichever comes first).
  2. Use the appropriate cleaning method. Cleaning usually begins and ends with water rinses, with an ammonia, a detergent (may include surfactants), or a water rinse in between. Refer to the Guide to Crop Protection or the product label for directions. Rule of thumb for products that don’t list a method: use water for water soluble formulations, detergent for EC, SC or flowable formulations and ammonia for less soluble products.
  3. Don’t rush. Allow water to circulate for at least 10 minutes, ammonia for 15 minutes and detergent for 5 minutes. Some labels may recommend leaving a rinse in the tank for a few hours or overnight, if possible.
  4. Remember the nozzles. Run the rinse through the boom and nozzles for about 5 minutes. Take an extra few minutes to inspect your nozzles and screens. New pesticide formulations are less likely to collect on screens but suspended particles or algae in water can also be culprits.

The first rinse of a sprayer is best disposed of by applying in the field that was treated. Further rinses should be disposed of in locations away from water and other sensitive areas.

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Scouting for Aster Leafhoppers

Submitted by John Gavloski, MAFRD Entomologist and Holly Derksen, MAFRD Field Crop Pathologist

Aster leafhoppers and other species of leafhoppers have been observed in large numbers in an individual winter wheat field in east-central North Dakota (NDSU Crop & Pest Report, May 14) At this time, aster leafhoppers have not been reported in Manitoba, and it is too early to know what the risk is for crops in Manitoba. Determining the risk will involve knowing when they arrive in Manitoba, what the populations are like, and what percent of the population carries the aster yellows phytoplasm. But it is not too early to start scouting for them in vegetation that is tall enough to sweep with a sweep net. Aster leafhoppers are small, about 2-3 mm long as adults, wedge-shaped, and have six distinctive dark coloured spots on their head (see image). Adults will readily fly when disturbed.

AsterLeafhopperFromWinterWheat.JG.Graysville,MB.June24,11

Aster leafhoppers can carry aster yellows, a disease caused by a bacterium-like organism known as a phytoplasma. Aster yellows can infect many crops including carrot, potato, flax, and cereals. Although canola is not a preferred host plant, aster leafhoppers will feed on it, and signs of aster yellows are quite visible in canola. Aster yellows was a significant problem for canola growers (and potentially cereal growers) in 2012. The leafhoppers blew in early and often in 2012 and had high levels of infectivity with aster yellows. The earlier a plant becomes infected with this disease, the more significant the yield effect can be. It is unknown at this time what percentage, if any, of the leafhopper population currently present in North Dakota is infected with aster yellows.

There are no economic thresholds for aster leafhopper in field crops. They are highly mobile insects that move quickly from crop to crop and new populations can blow in from the south at any time of the year.

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Should Manitoba growers be worried about the early reports of stripe rust in Alberta?

Submitted by Holly Derksen, MAFRD Field Crop Pathologist

Probably not.

Stripe rust has been reported in winter wheat fields in Alberta this spring (http://www.producer.com/2015/04/stripe-rust-in-alberta-winter-wheat/). This could indicate that the fungus overwintered on the crop. Overwintering of stripe rust in Canada also occurred in 2011, a year where there were measurable losses from stripe rust in both winter and spring wheat in Alberta and parts of Saskatchewan. That year a breakdown in resistance in the 2010 planted winter wheat crop led to higher infections leading into 2011. Persistent snow cover allowed for good overwintering conditions and a cool, wet spring favoured spread and infection of the stripe rust fungus. Growers in Alberta are being encouraged to vigilantly scout for the spread and proliferation of this disease this spring, especially in varieties that do not carry any resistance. Reports from Montana and Oregon have also indicated an early outbreak of stripe rust with fungicide applications being recommended in many cases.

In Manitoba, the majority of our inoculum blows in from the central US states by what is known as the “Puccinia Pathway”. Progress of this inoculum, as well as other cereal rusts, is documented on the USDA’s website (http://www.ars.usda.gov/News/docs.htm?docid=9757). To date, there have been a number of stripe rust detections with the furthest north located near Omaha, Nebraska. There have been no reports of stripe rust in Manitoba, however, inoculum can move quickly so growers should continue to scout their winter wheat and newly emerging spring wheat for early infections. The ideal timing for a fungicide application for protection against stripe rust in wheat is at the flag leaf stage. If rust infections are only noticed later in the year, especially past the flowering stage, a fungicide is likely unwarranted as the yield effect will be minimal.

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