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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Summary of Insects on Crops in Manitoba in 2016

A “Summary of Insects on Crops in Manitoba in 2016” is posted on the Manitoba Agriculture insect page at the link http://www.gov.mb.ca/agriculture/crops/insects/pubs/2016-summary.pdf

This report is based partially on observation by myself and my summer assistant. A large part of this information, however, is based on observations and reports from agronomists, farmers, farm production extension specialists, extension coordinators, and others who contributed information over the season. This information was helpful in providing timely updates on where and when insects were of concern throughout the season, and it is a compilation of this data that makes up this summary. Thank you very much to those who contributed information over the growing season.

Note also that the information in the summary is what has been observed personally or reported, and may not be complete in many instances. Although we encourage the reporting of information on insect populations and control to make our weekly updates as complete and useful as possible, some areas of high insect populations and areas where control took place may not have been reported.

I hope this information is useful in your winter planning and preparations for next year

Submitted by: John Gavloski, Entomologist, Manitoba Agriculture

Visit the Insect Pages of our Manitoba Agriculture website at: http://www.gov.mb.ca/agriculture/crops/insects/index.html

Manitoba Agriculture on Twitter: @MBGovAg
Manitoba Agriculture on YouTube: www.youtube.com/ManitobaAgriculture
Manitoba Agriculture website: www.manitoba.ca/agriculture

 

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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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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

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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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The Slow Dry Down & Harvest of the 2016 Grain Corn Crop

Modified from a previous Crop Chatter post made November 18, 2014.

November is here and there remains grain corn to be harvested in some parts of Manitoba. In some cases, moisture contents are still higher than wanted or wet field conditions are hampering progress. But with winter approaching, many are opting to harvest under the less than ideal conditions.

What are normal dry down rates in corn? The best dry down rates are in September. Under good weather conditions from the mid to end of September, dry down rates can vary from 0.75 to 1.0% per day (can be greater in some cases when conditions are warm, sunny and dry, or zero on cool, rainy days!). Into early October, dry down ranges from 0.5% to 0.75% per day. In late October, dry down rate will decrease to less than 0.33% per day. And into November, dry down rate will further decrease to 0.15% per day to negligible amounts.

It is important to keep in mind that moisture loss for any particular day may be higher or lower depending on the temperature, relative humidity, sunshine, wind or rain conditions that day.

However, regardless of kernel moisture content in November, if left standing the crop can dry down throughout the winter months to moisture contents below 20%.

Potential Yield Loss.  If the crop remains out longer than anticipated and into the winter months, potential yield loss will depend on many factors, including stalk strength, ear drop, snow cover or wildlife damage. Ear drop will vary by hybrid and environmental conditions as well as the amount of grain on the ear (smaller ears should stay attached better than larger ears).  Stalk strength should also be considered when evaluating harvest timing (and this includes assessments of stalk rots). Compromised stalk strength could lead to increased stalk breakage, resulting in lost yield.

If winter conditions are cool with minimal snowfall, then corn will continue to dry and can be harvested throughout the winter.

If you do find yourself in the position of needing/wanting to overwinter your corn, please touch base with your local MASC agent.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

Manitoba Agriculture on Twitter: @MBGovAg
Manitoba Agriculture on YouTube: www.youtube.com/ManitobaAgriculture
Manitoba Agriculture website: www.manitoba.ca/agriculture

 

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Is Manitoba’s Winter Wheat Crop Set Up to Survive Winter?

The most common question I receive over the winter months related to winter wheat production is “How is the cold weather/warm weather/lack of snow impacting my winter wheat?” Unfortunately, there are no easy answers over the winter months as we typically have to wait until spring when winter wheat breaks dormancy and stand establishment is known.

However, there can be a few key factors during fall establishment and weather conditions over the winter months that can provide guidance in terms of assessing weather and its impact to Manitoba’s winter wheat prior to the crop actively resuming growth next spring.

First step: record crop condition prior to winter. The crop stage and health/vigour of the crop as it heads into winter will provide an indication if the crop has a high chance of surviving the winter with minimal winterkill or winter injury. Ideally plants should be at the 3 leaf to 1 tiller stage and have well-developed crown tissue (and of course established into adequate standing stubble to ensure snow catch). And remember, the stage of crop development in the fall influences not only winter survival, but also yield potential, crop competitiveness, maturity and the risk of infection with diseases such as rust and fusarium head blight.

Second step: note the weather after seeding and prior to winter. Cool conditions in the fall where plants grow for 4 to 5 weeks, followed by 4 to 8 weeks (October to November) of growth that allow plant to acclimate and vernalize, is the ideal situation (relates back to an optimum seeding date of the first couple weeks of September). Read more about cold acclimation and vernalization here: http://cropchatter.com/winter-wheat-survival-impacted-by-fall-management-decisions-the-weather/. Another key weather factor is open field conditions with little or no snow cover until freeze-up as this allows soil temperatures to gradually decline to freezing levels.

If your winter wheat crop and the fall weather met the above conditions, your crop is likely well-positioned to survive Manitoba’s winter.

Third step: record any weather stresses over the winter months. In the fall, winter wheat producers can take all the necessary steps to set their crop up to survive winter with minimal winterkill or injury. However, it is often the winter/early spring weather in Manitoba that can impact winter survival.  Producers should take notes of cold snaps (how long they lasted, when did they occur) and the snow cover during those events to gauge potential impact to their winter wheat crop.

Regardless of the amount of cold acclimation, we typically need to receive good snow cover to protect the crop from the sustained cold temperatures normally seen in January and February in Manitoba. The ideal situation would be a minimum of 4 inches of trapped snow cover through December to early March to buffer soil temperature changes and provide protection to the crown tissue.

To assist with recording any soil temperature stresses, there is real-time monitoring of soil temperatures in the four winter wheat fields across Manitoba (see http://cropchatter.com/monitoring-real-time-soil-temperatures-in-manitoba-winter-wheat-fields/). The data will also be made available in the near future to the Winter Cereal Survival Model website at https://www.wheatworkers.ca/wcsm.php which can provide additional information on potential injury due to cold soil temperatures.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

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Monitoring Real-Time Soil Temperatures in Manitoba Winter Wheat Fields

Over the past three winters, Manitoba Agriculture through the AgWeather Program has been measuring soil temperatures real-time in winter wheat fields.  The monitoring of soil temperatures can provide an early indication if there is a concern for winter injury or winterkill.  The earlier a problem is identified or suspected, we are able to provide that information to industry so careful assessment of acres occurs in the spring.

There are 4 Manitoba Agriculture AgWeather Program weather stations measuring real time soil temperatures in winter wheat fields.  The sites are at Crystal City, Kleefeld, Oakburn and Virden.  Bookmark the link: ftp://mawpvs.dyndns.org/Tx_DMZ/WWST2016_17.png

In the coming weeks, the data will also be made available to Western Ag for their Winter Cereal Survival Model, available at the following link: http://www.wheatworkers.ca/FowlerSite/winter_cereals/WWModel.php.

I would highly recommend taking the time to read instructions on how to use the site and interpret the results.  Click here for instructions on how to use the model.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

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Can Stripe Rust Overwinter in Manitoba?

Short Answer: Yes.

Long Answer: Normally in Manitoba, the majority of our inoculum blows in from the central US states by what is known as the “Puccinia Pathway”. However, according to Dr. Brent McCallum, a Research Scientist with AAFC in Morden, MB, there was evidence of both stripe and leaf rust overwintering on winter wheat in Manitoba a few years ago but at such low levels it wasn’t a concern. Dr. Kelly Turkington, a Research Scientist with AAFC in Lacombe, AB, also indicated overwintering of stripe rust occurred in Alberta and parts of Saskatchewan in 2010/11 where there were measurable losses. In that particular year, there was a breakdown of resistance in the 2010 planted winter wheat crop and that led to higher infections into 2011.

So yes, stripe rust can overwinter. However, the ability of stripe rust to overwinter in Manitoba, or elsewhere, would depend on factors such as the severity of the winter and snowfall amounts.

If stripe rust is seen in the fall, take note of the variety and its resistance rating. Although nothing can be done about variety selection at this point, in the future consider stripe rust resistance when evaluating and selecting winter wheat varieties. Genetics….it’s a fast and easy way to protect your crop from disease pressure!

If winter weather conditions allow for overwintering of stripe rust, it could provide a local source of inoculum early in the spring – as early as the crop starts actively growing. A cool, wet spring could also favor spread and infection of stripe rust, not only to winter wheat but to other crops such as spring wheat.

If you do see stripe rust this fall in your winter wheat crop, mark those fields as ones to watch as soon as the crop breaks dormancy next spring. If stripe rust does overwinter, a fungicide application may be necessary.

Should a fall fungicide application be considered?

There has been some recent research conducted looking at the yield response and economics of a fall fungicide application in winter wheat. From 2011 to 2013, researchers from AAFC conducted a study across Western Canada looking at a variety of management factors, including one looking at a fall fungicide application. Results were recently reported in Top Crop Manager at http://www.topcropmanager.com/business-management/improving-winter-wheat-19554. The following statements are from the article.

In regards to the fall fungicide treatment, “the study showed some benefit from the fall foliar fungicide treatment, however the increase was small and resulted in decreased net returns,” says Turkington (who was involved with the study). “In areas with confirmed stripe rust in the fall, the yields gains were a bit better. However the cost of application is prohibitive at this point compared to no application. ”

More research is currently underway by Turkington and Dr. Randy Kutcher (University of Saskatchewan) looking at a fall fungicide application, a spring fungicide application at flag leaf emergence, and a dual application (one in the fall and one in the spring).  “The preliminary results after the first two years aren’t showing much of a benefit from the fall foliar fungicide application, similar to our recent study,” Turkington says. “Some of the results suggest a dual fall and spring application does not provide any additional benefit over a spring application in Western Canada.”

So for this fall, don’t pull out the sprayer if you see stripe rust in your winter wheat.  But, be ready to scout in the spring! And look for more updates to current winter wheat research underway across Western Canada.

Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist and Holly Derksen, Field Crops Pathologist, Manitoba Agriculture; with assistance from Dr. Brent McCallum, AAFC Morden and Dr. Kelly Turkington, AAFC Lacombe.

Manitoba Agriculture on Twitter: @MBGovAg
Manitoba Agriculture on YouTube: www.youtube.com/ManitobaAgriculture
Manitoba Agriculture website: www.manitoba.ca/agriculture

 

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Testing Weeds for Herbicide-Resistance

Do you have weeds that survived this year’s herbicide application(s)? Since there are many factors that can contribute to weed escapes, consider:

  • The distribution of escaped weeds. Herbicide-resistant weeds tend to occur in patches as opposed to geometric patterns (e.g. spray miss) or throughout the field (e.g. tolerant weeds).
  • Possibility of reduced herbicide efficacy. 2016 was a challenging year for weed management due to untimely and excessive rainfall. In many cases, weeds escaped because of herbicide application timing with respect to weed growth stage, limited herbicide choices because of crop growth stage (when producers finally could get on their fields) and product rainfastness.
  • Weed species. Annual weed species, like wild oat, green foxtail, cleavers, kochia, hemp-nettle, smartweeds, ragweeds and wild mustard, may be more likely to develop resistance compared with other weed species. Because the development of herbicide-resistance is based on chance, resistant weed patches are typically a single species, as opposed to non-resistant weed escapes, which may affect multiple weed species.

Suspect weed escapes can be confirmed as resistant or susceptible by herbicide-resistance testing. For most weeds, dry, mature seed is required for the analysis.  Although more is better, many labs require at least 100 g of small weed seeds (e.g. cleavers) and 200-250 g of large weed seeds (e.g. wild oat).  Weed seed samples should be submitted by December 31st, 2016 to either:

For suspected glyphosate-resistant kochia, a genetic-based tissue test is also available from the Pest Surveillance Initiative: http://www.mbpestlab.ca/field-testing/. In this case, about 5 to 10 g of green plant tissue (e.g. leaves and stems from plant tips) is needed for the analysis. Samples should be placed on ice and shipped immediately after collection. The advantage of the genetic test (vs. seed analysis) for kochia is the ability to determine resistance in-season.

picture1

Submitted by: Jeanette Gaultier, Provincial Weed Specialist, Manitoba Agriculture

For more information on resistant weeds and weed management, visit the Manitoba Agriculture website: http://www.gov.mb.ca/agriculture/crops/weeds/

 

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Are Herbicides Still Effective After a Fall Frost?

Fall is a great time to control perennials such as Canada thistle, perennial sow thistle and dandelion. As temperatures cool, nutrients move from the leaves down into the roots and if a herbicide can be taken up and translocated with those nutrients, it can equal better control. Glyphosate and/or the group 4s are examples of herbicides that provide effective fall control of perennials.

A frost event though, can kill some weeds or can damage leaf tissue which will reduce herbicide uptake and reduce the level of weed control. Within the next few days after the frost, you need to assess the target weeds in the areas that you want to obtain control – are the weeds still growing?  How much leaf tissue has been damaged?

Light frost: A light frost (0 to -3°C) can actually improve weed control by increasing herbicide translocation to the root.  However, duration of the frost also plays a role.  Check your weeds for frost damage if you plan on a herbicide application after a light frost.  Herbicides can only be taken up and translocated by weeds that are healthy and actively growing.

If you do spray – spray in the afternoon when temperatures are warm and sunny, as this will help with herbicide uptake.   You’re looking for daytime temperatures of ~8 to 10°C for at least 2 hours. Use rates appropriate to the stage and time of year – fall applications of glyphosate are recommended at a higher rate than when controlling weeds pre-harvest.

Hard frost: Depending on the damage, a hard frost (≤ -5°C) can put an end to (effective) post-harvest weed control. However, if the plant leaves are still shiny green with minimal leaf tissue damage (i.e. not blackened/brown or brittle) or if less than 40% of the plant has more serious leaf tissue damage (i.e. blackened/brown or brittle) there may still be a window to make a herbicide application. Wait at least 48 hours before assessing frost damage after a hard frost.

If you do spray – read the ‘If you spray’ paragraph above, it still applies.  You need those daytime temperatures to hit ~8 to 10°C for at least 2 hours. In addition, consider your coverage – higher water volumes may improve uptake in more heavily damaged weeds.

One last thing – look at the forecast for the next week following the application.  If daytime temperatures are below 8°C and/or if night-time temperatures are forecasted to continually be below freezing, it may be too late to make the application to get the economic control you are looking for.

Submitted by: Jeanette Gaultier, Provincial Weed Specialist, Manitoba Agriculture

Visit Manitoba Agriculture Crops webpage for more current topics: www.gov.mb.ca/agriculture/crops/seasonal-reports/current-crop-topics.html#agronomy; or the Manitoba Agriculture Weeds webpage for more information on fall control of dandelion and quackgrass: www.gov.mb.ca/agriculture/crops/weeds/.

 

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What areas of Manitoba received the most rainfall in early October 2016?

The following precipitation maps are provided by Manitoba Agriculture’s Ag Weather Program.  The displayed map shows Total Accumulated Precipitation from October 2 to October 4, 2016.

Picture1

 

 

 

 

 

Follow Manitoba Agriculture on Twitter at @MBGovAg to get these seasonal reports and more.

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ANNUAL OR WINTER ANNUAL?

Fall is the most effective time to manage certain weed species. The recommendations seem clear-cut:  winter annuals = fall herbicide application/tillage; annuals = no fall management.  But figuring out the life cycle of the weeds in your field this fall is the catch……

Bromes, cleavers, chickweed, night-flowering catchfly, narrow-leaved hawk’s-beard, shepherd’s-purse and stinkweed are all facultative winter annuals, meaning that they can germinate in either the fall or the spring depending on environmental conditions.  These weeds are often best managed in the fall, if populations warrant it.  In general, waiting until about this time of year maximizes fall-germinating flushes of winter annuals.  If using a herbicide, consider weed stage and the weather forecast, prior to application.

The problem is, given the right conditions – like the long falls and mild winters we’ve had the last few years –several of our annual weed species can also successfully overwinter:

Biennial wormwood – Despite its name, biennial wormwood behaves like an annual in agricultural fields.  When scouting, estimate the average growth stage of biennial wormwood populations in a field.  If the majority of the plants have already set seed, a fall herbicide application won’t help.  An application may be worthwhile only if there is a large flush of biennial wormwood that haven’t set seed and are less than ~3 inches tall.  Herbicide tank-mixes containing glyphosate + group 4 are more effective than glyphosate + group 2 on this weed.

Round-leaved mallow (RLM) – This annual weed can act as either a winter annual or a short-lived perennial, although it is more sensitive to freezing than our common winter annuals.  Mild winters in 2015 & 2016 provided the right conditions for RLM to overwinter, allowing it to become (even more) problematic in certain fields over the last few growing seasons.  Long range forecasters are predicting a harsh winter across the prairies this year, which should control RLM.  However, if you have little faith in forecasts and decide to apply a herbicide, glyphosate mixed with either Distinct or DyVel DSp has activity on this weed.

IMG_20150915_081215

Round-leaved mallow post-harvest


Stork’s bill –
Like biennial wormwood, stork’s bill tends to be predominantly an annual in Manitoba.  If this is a problem weed for you, scout affected fields to determine average weed stage.  Again, if most of your stork’s bill has set seed you’re better off working on a plan for next year.  Stork’s bill, especially larger plants, is relatively tolerant of many herbicides.  If you decide to apply a herbicide because of stork’s bill this fall, glyphosate + group 2 or glyphosate + group 2 + group 4 on weeds up to the 4 to 6 leaf stage is probably your best bet.

Submitted by: Jeanette Gaultier, Provincial Weed Specialist, Manitoba Agriculture

Information on more weeds and their life cycles is available at: www.gov.mb.ca/agriculture/crops/weeds/
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Winter Wheat Survival – Impacted by Fall Management Decisions & the Weather!

For winter wheat, survival through our cold Manitoba winters is directly influenced by fall management decisions, including variety selection, seeding date and depth, adequate plant stands, fertility and stubble height/density. Optimal winter survival can also be influenced by fall weather conditions and snow cover.

What is the ideal situation heading into the winter?

  • Plant stage would be at the 3 to 4 leaf with 1 to 2 tillers, and well developed crown tissue.
  • Cool conditions in the fall, where plants would grow for 4-5 weeks, followed by 4-8 weeks (October to November) of growth that allowed plant to acclimate (harden off) and vernalize (giving the plant the signal to flower next spring).
  • A minimum of 4 inches of trapped snow cover through December to early March to buffer soil temperature changes and provide protection to the crown tissue.

What is cold acclimation and vernalization? 

Cold Acclimation. The ability of the winter wheat plant to survive the winter often depends on its ability to withstand low temperatures.  Under normal field conditions, eight to twelve weeks of growth is usually required for the full development of winter hardiness.  The first four to five weeks is a period of active growth that takes place when average daily soil temperatures at a depth of two inches (5 cm) are above 9°C. Both the cold acclimation process and winter survival require energy and this period of warm temperature allows for the establishment of healthy vigorous plants. Plants with well developed crowns before freeze-up are most desirable.  However, plants that enter the winter with two to three leaves are usually not seriously disadvantaged.

Cold acclimation of winter wheat plants begins once fall temperatures drop below 9°C.   In the field, four to eight weeks at temperatures below 9°C is usually required to fully cold harden plants. However, regardless of the amount of cold acclimation, the wheat plant must receive insulating snow cover to survive the cold prairie winters.

Vernalization. During the period of cold acclimation, the low temperatures also initiate in the plant a physiological response called vernalization.  During vernalization, the plant converts from vegetative to reproductive growth and the reproductive structures are developed.  Because of this vernalization requirement, winter wheat produces only leaves for both the main stem and tillers aboveground in the fall in preparation for winter.  The growing point and buds of both the main stem and tillers remain belowground, insulated against the cold winter temperatures. Once vernalization requirements are met, the growing point differentiates and develops an embryonic head.  At this time, wheat head size or total number of spikelets per head is determined.  What is important to note here is neither seedling growth nor tillering is required for vernalization to occur.  This process can begin in seeds as soon as they absorb water and swell.  Hence, late planted wheat that has not emerged prior to winter should be adequately vernalized.   Or in extreme conditions, vernalization may occur under cool spring conditions.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

Manitoba Agriculture on Twitter: @MBGovAg
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Manitoba Agriculture website: www.manitoba.ca/agriculture
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3 Questions to Ask Your Corn Seed Dealer about Goss’s Wilt Ratings

Goss’s Wilt was reported in several areas of Manitoba during the 2016 growing season. Goss’s Wilt is a bacterial disease and CANNOT be controlled by a fungicide. Managing Goss’s Wilt include weed control, tillage and most importantly rotation and hybrid selection (genetics!). And with the seed ordering season quickly upon Manitoba corn growers, here are 3 questions you should ask your seed dealer about Goss’s Wilt ratings.  The more information you have, the more informed decision you can make.

But before that, some key points:

  • there is no third party data available for Manitoba hybrids;
  • ratings will likely change over time as more years of testing are completed, in different locations and conditions;
  • resistance does not equal immunity! Plants don’t have immune systems and therefore can’t be immune to any disease. Depending on the level of disease pressure, hybrids that are rated as resistant/tolerant can still be infected to some degree. If disease pressure is high (i.e. high inoculum levels, conducive environmental conditions for a long period of time), yield loss due to Goss’s Wilt can still occur in the best rated hybrids.

But First! Before you start asking your seed dealer questions, if you experienced Goss’s Wilt this year perhaps there’s a few questions you can ask yourself (or your neighbor if they had Goss’s Wilt). Was Goss’s Wilt present in every corn field, just one or a few? What were the levels of Goss’s Wilt in individual fields? Do you (or your neighbor) know the resistance rating of those hybrids, both exhibiting symptoms or not exhibiting symptoms? Are you keeping good field notes? While there is no third party data available, you could start making subjective on-farm comparisons (but at the same time recognizing the limitations of those comparisons).

Question 1: What is the rating scale used?  Since there is no universal system for determining Goss’s Wilt ratings in Manitoba, there can be differences between companies and their hybrid ratings. For some companies, a rating scale of 1 to 9 is used, where 1=Poor and 9=Excellent.  However, other companies use the same 1 to 9 scale, but 1 = Resistant and 9 = Susceptible. Then there are others that only use a 1 to 5 scale.  So read the fine print….what does a 3 really mean? And remember, since there is no universal system in Manitoba, you can only really compare between hybrids within a single company.

Question 2: How is the testing done to establish the ratings? Ask if the testing is done under natural infection or through disease nurseries with inoculation.  Relying on natural infection to determine ratings is not as dependable as disease nurseries with inoculation (and wounding). Goss’s Wilt typically shows up in patches and can be very weather –dependent. Also, Goss’s Wilt needs an entry point, often caused by hail, wind damage, etc. No symptoms under natural infection may not indicate resistance, but instead conditions weren’t conducive for infection, i.e. escape.  Artificially inoculated nurseries may be resource intensive, but provide a better chance for determining resistance levels of hybrids being evaluated.

Question 3: Where is the testing done to establish the ratings? For some companies, testing is done in the United States, while other companies have established trials in Manitoba.  Why would this be important? There is variability in the pathogen population, where strains are separated into groups based on DNA analysis. Further research is on-going at the University of Manitoba with funding provided by the Manitoba Corn Growers Association and Growing Forward 2 to determine the strains of Goss’s Wilt present in Manitoba. We are only beginning to understand the pathogen population here in Manitoba so there is more research that needs to be done to fully understand the role of host resistance. In the meantime, testing conducted with disease nurseries and inoculation, either here or elsewhere, is a good step to provide information on hybrid resistance ratings.

Remember, resistance ratings to Goss’s Wilt is only one of many hybrid characteristics producers should consider when choosing their hybrid!

Written by: Pam de Rocquigny, Provincial Cereal Crops Specialist & Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

For more information on Goss’s Wilt, visit Manitoba Agriculture’s website at https://www.gov.mb.ca/agriculture/crops/plant-diseases/goss-wilt.html

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Weather & Hybrid Characteristics – Their Roles in Grain Corn Dry Down

Updated from Crop Chatter Posts Made in 2012 and 2015

Grain corn in Manitoba is maturing quickly, and some of the earliest maturing fields have reached physiological maturity. Normal plant processes and weather conditions are the major influences on grain dry down, although hybrid characteristics can also play a role. As corn harvest approaches, a quick review of the facts concerning grain drydown might be helpful.

Grain drydown can be separated into two stages: the grain fill period and after physiological maturity.

Drydown During Grain Fill. The grain fill stages (R1 to R5) begins at flowering and is completed at physiological maturity. Grain filling is characterized by the rapid accumulation of dry matter in the kernel and the rapid movement of water out of the kernel.  Decreases in kernel moisture occur from a combination of actual water loss (evaporation) from the kernel surface and the accumulation of dry matter.  The corn plant uses “internal plumbing” to move water out of the kernel since water movement out of the kernel is regulated by how much dry matter is being forced into the kernel.  The corn plant is much more efficient in removing water from the kernel using its “internal plumbing” instead of physical evaporation through the kernel surface.

Drydown After Physiological Maturity. Physiological maturity (R6) occurs when kernel moisture is at approximately 30% (but can vary).  At this stage of growth, a layer of cells at the base of the kernel dies and turns black (hence black layer), the “internal plumbing” is therefore disconnected, and a barrier is formed between the kernel and the corn plant.  For this reason, post-maturity grain moisture loss occurs primarily by evaporative loss from the kernel itself. Research many years ago established that post-maturity moisture loss through the kernel connective tissues (placental tissues) back to the cob is essentially non-existent.

Role of Weather. As moisture loss after maturity is due to physical evaporation, field drying of mature corn grain is influenced primarily by weather factors, especially temperature and humidity.  In simple terms, warmer temperatures and lower humidity encourage rapid field drying of corn grain.

Because moisture loss is greatest just after physiological maturity, both because the weather is usually warmer and because wet kernels lose water more easily, it stands to reason that a corn crop that matures earlier in the season will dry down faster than a crop that matures later in the season.  However, it is important to keep in mind that grain moisture loss for any particular day may be quite high or low depending on the exact temperature, humidity, sunshine, or rain conditions that day. It is not unheard of for grain moisture to decline more than one percentage point per day for a period of days when conditions are warm, sunny and dry. By the same token, there may be zero dry down on cool, rainy days.

Role of Hybrid Characteristics.  A number of hybrid characteristics can influence the rate of dry down, but to a lesser degree than weather. However, when weather conditions are not favorable for rapid grain dry down, hybrid characteristics that influence the rate of grain drying become more important.  The relative importance of each trait varies throughout the duration of the field dry down process and, as mentioned earlier, is most influential when weather conditions are not conducive for rapid grain drying.

  • Husk Leaf Number. The fewer the number of husk leaves, the more rapid the grain moisture loss.
  • Husk Leaf Thickness. The thinner the husk leaves, the more rapid the grain moisture loss.
  • Husk Leaf Senescence. The sooner the husk leaves senesce (die), the more rapid the grain moisture loss.
  • Husk Coverage of the Ear. The less the husk covers the tip of the ear, the more rapid the grain moisture loss.
  • Husk Tightness. The looser the husk covers the ear, the more rapid the grain moisture loss.
  • Ear Declination. The sooner the ears drop from an upright position to a downward position, the more rapid the grain moisture loss.
  • Cob Diameter. The narrower the cob diameter, the more rapid the grain moisture loss.
  • Kernel Type.  Flint-dent kernel types tend to dry down slower in comparison to dent kernel types due to the harder nature of the kernel.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

Manitoba Agriculture on Twitter: @MBGovAg
Manitoba Agriculture on YouTube: www.youtube.com/ManitobaAgriculture
Manitoba Agriculture website: www.manitoba.ca/agriculture
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Tips to Marketing Downgraded Crops

Over the past few weeks, we’ve heard about the impact of the poor weather conditions over the harvest period on the quality of harvested grain.  With the crop off the field and into the bin, marketing now becomes the focus of many producers.

In the attached article (updated from 2014) by Gary Smart, Farm Management Specialist with Manitoba Agriculture, he provides excellent information to cope with downgraded crops.  Some highlights include:

  • When marketing poor quality grain, be prepared and don’t panic, especially right at harvest time.
  • Know the quality and find a buyer who will offer the best value.
  • Take good samples. Without thorough samples, it is tough to know what is actually in the bin.
  • Communicate with the buyer if already some of this year’s crop is already contracted.
  • Unless cash flow is an issue on the farm, being patient could be the best action to take as new markets may arise for poor quality grain.

ARTICLE: Marketing Poor Quality Grain (2016)

For further information, support and resources, contact the Manitoba Agriculture’s Farm Management Team at http://www.gov.mb.ca/agriculture/business-and-economics/farm-business-management-contacts.html

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

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Canadian Grain Commission’s Harvest Sample Program

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Photo Credit: Canadian Grain Commission

Mitchell Japp, the Provincial Cereal Crops Specialist with the Saskatchewan Ministry of Agriculture, recently wrote an article on the Canadian Grain Commission’s Harvest Sample Program – what it is, how to request a sample kit in order to submit a harvest sample, and getting results.  The complete article is available here: Harvest Sample Program.

The CGC is providing a valuable service to individual farmers and industry with the Harvest Sample Program, but it takes participation for it to work.  I would encourage Crop Chatter subscribers to click on the link and read Mitchell’s article!

 

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

For more information, visit the Canadian Grain Commission page.
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Northern Corn Rootworm – Additional Established Populations Found in Manitoba

Established populations of Northern Corn Rootworm have been found in additional locations, as reported in the most recent Manitoba Insect & Disease Update – August 17, 2016.  The following is provided by John Gavloski, Provincial Entomologist with Manitoba Agriculture.

When corn is grown in the same field for several years in a row, it becomes more susceptible to various potential pests. One such pest is northern corn rootworm (Diabrotica barberi). Until last year only the occasional specimen of northern corn rootworm had been found in Manitoba, and not at levels that appeared to be an established population in a corn field. Last year we did find a well established population in a field in the Souris area. This year we are looking more intensively for them, and have found established populations in corn fields near Morden and Winkler. All fields where they have been found so far have had a long history of consecutive corn being grown in the same field.

This time of year you will see the adult beetles (Figure 1), often on the silks of the corn plants. These adult beetles are generally not of concern, and will lay eggs in the soil of the corn field they are in. When larvae hatch from these eggs the next spring, if there is corn in the field again they will feed on the corn roots. If corn is not in the field they will starve to death. Thus crop rotation is the easiest and cheapest way of dealing with them.

northern-corn-rootworm-on-corn

Figure 1. Northern Corn Rootworm

If anyone finds corn rootworm on their corn, or insects they think may be corn rootworm, we are trying to verify the range of this insect in Manitoba. So samples would be welcome and can be sent to John Gavloski, Manitoba Agriculture, Box 1149, 65-3rd Ave. NE, Carman, MB, R0G 0J0.

Visit the Insect Pages of Manitoba Agriculture’s website at: http://www.gov.mb.ca/agriculture/crops/insects/index.html

 

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Preventing Stored Grain Insects at Harvest Time

#Harvest16 is here and a below is a quick review (from the most recent Manitoba Disease & Insect Update – August 10, 2016) of preventing stored grain insects from John Gavloski, Provincial Entomologist with Manitoba Agriculture.

Preventing stored grain insects: A reminder before moving and storing new grain to clean old grain out of bins, augers, combines, truck beds, and other areas where grain or grain debris may be. Infestations of stored grain insects such as rusty grain beetles usually do not get started by harvesting the insects along with the grain. They are often the result of insects already being present in bins or equipment used to move grain, or insects being able to get into the stored grain through openings in bins or storage structures. Figure 1 (below) is a picture of a sawtoothed grain beetle (top right), red flour beetle (bottom left), and rusty grain beetle (bottom right) with a grain of wheat (top left) to give perspective on size.

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Figure 1. Some beetles that may occur in stored grain.

Some insects in stored grain, such as the rusty grain beetle, will feed primarily on the grain, while others, such as foreign grain beetle, may be feeding primarily on molds growing on grain that is too moist. So it is good to know the species you are dealing with as management options may differ. Additional information on identifying and managing insects on stored grain can be found at: http://www.gov.mb.ca/agriculture/crops/insects/prevention-and-management-of-insects-and-mites-in-farm-stored-grain.html

For long-term storage of grain, lowering the grain temperature below 15C as soon as possible after the grain is placed in storage can help minimize the risk of stored grain insects. Below 15C potential insect pests of stored grain stop laying eggs and development stops. Grain that is not aerated or moved after harvest can often remain warm enough for insects to survive the winter.

Following proper storage recommendations is also a key component in Cereals Canada’s Keep It Clean initiative. More information is available at http://www.cerealscanada.ca/keep-it-clean/

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

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