Summary of Presentations from the International Congress of Entomology, September 25-30, 2016

Submitted & Summarized by: John Gavloski, Entomologist, Manitoba Agriculture

The following link provides highlights from some of the presentations most pertinent to agronomists and farmers in Manitoba. Please contact me for further information on these presentations or meetings. Due to there being concurrent sessions at these meetings, there were many more presentations than what is presented in this summary. These were selected because of their relevance or potential interest to those working in agriculture in Manitoba. I have categorized the presentation reported by commodity group or discipline.

The information presented is a combination of material from oral presentations, poster presentations and provided as abstracts for the various symposiums. Many presentations have multiple authors, however only the presenting author is reported in this summary.

http://www.gov.mb.ca/agriculture/crops/insects/pubs/int-congress-of-entomology-2016-summary.pdf

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

 

 

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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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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.

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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.

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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.

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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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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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Minimum Air Temperatures – September 13/14, 2016

From Manitoba Agriculture’s AgWeather Program, a map showing minimum air temperatures reached September 13/14:

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In addition, the Crop Weather Report is a weekly summary of temperature (max., min., avg) and total rainfall along with seasonal accumulations of degree days, corn heat units and rainfall (actuals and % of normal) are provided for about 50 locations in the five regions.

Following are links to weather maps in pdf format for the time period of May 1st to September 11th:

The above maps will be updated every Monday during the growing season. They are available on the Manitoba Agriculture weather web site at http://www.gov.mb.ca/agriculture/weather/index.html .

For more information or to subscribe to the weekly Crop and Weather reports send your request to [email protected].

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

 

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It’s That Time of Year – Talking Fall Frosts in Manitoba

UPDATED FROM ARCHIVED CROP CHATTER POST MADE AUGUST 15, 2013

As we enter in the later parts of the growing season, fall frost enters the minds of most people involved in the grain industry.  As everyone knows, frost can have an impact on a crop’s quality and yield.  There were a few areas reporting a light frost event the morning of September 14th.

The extent of frost damage to a crop will depend on several factors. The species, stage, and hardening of the crop, the soil type and soil moisture, the actual air temperature, the duration of freezing, and the rapidity with which freezing takes place are all important. A drop in air temperature of short duration will cause less damage than a prolonged periodthe same low temperature. When the air temperature drops to 0°C, cereal and other crops may not sustain damage. Rather, damage or total loss is more common when minimum temperatures drop below -2°C, often referred to as a killing frost.

Given its sporadic nature, long-range forecasting of frost is nearly impossible. Rather, the climate record of an area is used to determine probable dates of frost based on long-term temperature records. While this will not provide an actual frost date in a particular year, it will present the likelihood that frost may occur on a certain date. This can be a valuable planning tool.

The Manitoba Ag-Weather Program released updated FIRST FALL FROST MAPS in 2014 which are made from the new township gridded normal from a wider dataset of 1950-2010:

For additional information, please visit Manitoba Agriculture’s AgWeather Program at http://www.gov.mb.ca/agriculture/weather/agricultural-climate-of-mb.html.

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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So we had a Frost on our Soybean, Now what?

The first step in accessing frost damage is asking how cold it was last night. A light frost of -1°C for short durations may clip off a few off the top leaves with no effect on yield. The concern begins when a killing frost at least -2°C occurs for an extended period of time. In this situation you will see frozen leaves and pods throughout the canopy.  This may cause quality issues and yield reduction if the crop has not reached full maturity.

See the latest MB Ag Weather latest frost map: http://www.gov.mb.ca/agriculture/weather/pubs/minimum-air-temperature.pdf

What growth stage are your beans at, see http://www.manitobapulse.ca/soybean-staging-guide/ as a reference.

A killing frost at the R8 growth stage will see no yield or quality loss. The R8 stage is when the leaves have dropped off, all pods are brown, and seeds rattle within the pods when plants are shaken.

If however your beans are at the R7 growth stage, (which means one pod on the plant has reached its mature color), research has shown yield loss can range from 5-10 % dependent upon the severity of the frost. Quality issues in the way of green seed may also occur.

Finally, if your beans are at the R6 growth stage-(this is where pods containing a green seed that fills the pod cavity at one of the four uppermost nodes on main stem), yield losses can range from 20-30 %.  You will also have green seed issues which can also lead to marketing concerns.

There are a few areas in Manitoba where the beans are at the end of this R6 growth stage.  Most of the beans in Manitoba are at the R7-R8 growth stage. A light frost should not affect yield and quality for these beans. If beans were at the R6 growth stage and a hard frost occurred yield and quality losses would be noticeable.

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Picture: Light frost damage on soybeans near Hamiota, 2016.

Photo from L.Grenkow, Manitoba Pulse Soybean Growers

Submitted by: Dennis Lange, Industry Development Specialist-Pulses, Manitoba Agriculture

 

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