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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Winter Wheat Stand Assessment – Start Now but be Patient!

Winter wheat is starting to resume growth after what has been a generally mild winter in Manitoba.  Now is the time producers across Manitoba can start assessing their winter wheat stands.

So what should the plant stand be in a winter wheat field?   An optimum winter wheat plant stand consists of 20-30 plants per square foot.  However, it is well-known that winter wheat has the amazing ability to compensate for thin plant stands by increasing tillering.  The impact of poor stands on yield is not black and white.  Research has shown that a plant stand of 7-8 plants per square foot yields about 70-80% of a normal stand (see Target Plant Stands for Winter Wheat).   However, the key point to remember is a thin stand won’t likely compensate fully to produce full yields.

Trying to make the decision on whether to keep that winter wheat stand or replant is never easy and SHOULDN’T BE RUSHED. Stands are rarely uniform and the variability within the field makes the decision more difficult.  What is important to keep in mind is timely management in the spring increases the success of a winter wheat crop. A thin winter wheat stand with timely weed control and nitrogen fertilizer applied early will almost always be worth saving.

AgriInsurance Considerations:

Winter wheat and fall rye destroyed prior to June 20th are not be eligible for a Stage 1 indemnity (50% coverage), only the 25% reseed benefit for losses prior to June 20th. If you are considering reseeding due to  poor plant stands and before destroying any winter wheat fields, please contact your local MASC insurance agent.  For more information, please visit MASC’s website at: http://www.masc.mb.ca/masc.nsf/program_winter_wheat.html

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

For more information on winter wheat production, visit Manitoba Agriculture’s website at https://www.gov.mb.ca/agriculture/crops/production/winter-wheat.html
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Updated Soil Temperatures in Winter Wheat Fields 2014/15

Soil temperatures in four winter wheat fields were measured throughout the 2014/15 winter. Plotting soil temperatures against various ‘hardiness” curves can provide an early indication if there is a concern for winter injury or winterkill.  I had posted initial data (up to beginning of March – http://cropchatter.com/early-indicators-for-wheat-survival-in-2015/), and presented that data at the Winter Cereals Manitoba AGM middle of March.

However, the figure is now updated to include data up until middle of April when the weather stations were removed from the fields.

Figure 1: 2014/15 Soil Temperatures Measured at 1 Inch Depth in Four Winter Wheat Fields

2014 15 Soil Temperatures

 Data Source:  MAFRD AgWeather Program

Since majority of winter wheat acres are considered “well-hardened” and soil temperatures didn’t reach levels that went below the “high hardiness’ curve, winterkill isn’t expected to be a large concern based solely on soil temperatures measured in these fields over the winter.  However, since soil temperatures at one location did dip below the “mid hardiness’ curve, or at some locations got close to that curve, some areas within fields may be impacted where there was perhaps minimal snow cover due to lack of stubble, etc.  Each field should still be scouted and assessed as growth resumes in earnest over the next few weeks.

Note: You will notice the hardening curves end beginning of April as I don’t have data to continue the curve to May 1st.  However, imagine a curve for each line continuing upward until approximately the -2°C mark. 

Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD 

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Assessing Winter Wheat Survival

Spring is right around the corner…hopefully! It is that time of year where producers start thinking about their winter wheat crop and how it survived our Manitoba winter.  There are 3 common ways to assess winter survival.

1. Sod Extraction Method – A producer can extract several ‘sods’ from the field with a shovel.  Warm up the sods inside while keeping the soil moist.  In 5 to 7 days, assess the crowns for new root growth which indicates the plant has survived.

2.  Bag Test Method – This method was developed by Ducks Unlimited in North Dakota and involves five easy steps:

1)      Dig or chisel plants out of the soil without damaging the crown.

2)      Rinse the soil off the crown and roots.

3)      Using scissors, trim off the roots and leaves and all but one inch of the stem above the crown.

4)      Put the crowns in a Ziploc bag and puff some air into it before sealing.

5)      Keep at room temperature and observe every 2 days.  Repeat the rinsing and air every 2 days.

Plants that are alive will extend leaves and grow new white roots.  If new growth is not observed after 6 days, consider the plant dead.  There is a good YouTube® video illustrating this method at: http://www.youtube.com/watch?v=soCj2OsLJ_w&feature=youtu.be

3. The Wait for Spring Growth Method – This method requires producers wait until the crop breaks dormancy and new root growth commences out in the field; this could take until mid-May in some years depending on spring weather conditions.  This method does still require producers dig up plants within the field as brown, dried leaves do not necessarily indicate winter injury, and green overwintering leaves are not a sure sign that the crop has survived.  To properly assess, dig up some plants, rinse the roots with water and examine the crown for the development of new white roots.  If new roots are developing, and the crown appears white and healthy, the plant is likely in good condition.

Regardless of method used to assess winter survival, producers should still scout their winter wheat fields to determine plant stands. It has occurred where plants will green up and then slowly go ‘backwards’ and eventually die; there are enough nutrients in the crown to allow the plants to green up, but if winter injury occurred, it can cause vascular damage so that the nutrients that are left cannot move, or root rot diseases can move in and kill the plants.  So don’t scout the field once and assume all is okay.

Additional information on winter wheat production is available on Crop Chatter:

 Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD

Additional information on winter wheat production is available on MAFRD’s website at: http://www.gov.mb.ca/agriculture/crops/production/winter-wheat.html
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Update on Winter Wheat Seeded Fall 2014

Despite the delayed harvest of 2014, Manitoba producers did seed a limited acreage of winter wheat.  It is estimated seeded acres are at or below 200,000, which is down from what was seeded in Fall 2013 and 2012 (see Table 1).

Table 1: Historical Acres of Winter Wheat Seeded in Manitoba

winter wheat seeded acresSource:  MASC Seeded Acreage Reports 2009-2014.

 

Fall Establishment.  The good news is much of that seeding occurred under “optimal” conditions – before or at recommended seeding dates, into fields with standing stubble, and into good soil moisture.  The winter wheat crop emerged quickly and uniformly, reaching the recommended stage of 3 leaf to 1 tiller prior to snow fall.

The stage of crop development in the fall is important as it not only influences winter survival, but it can also impact yield potential, crop competiveness and maturity. However, winter survival is also influenced by fall management practices, including variety selection, seeding date and depth, fertilizer placement and stubble conditions.

Take Notes Now & Over the Winter.  Manitoba producers have done their part to ensure their crop reaches maximum winter hardiness. Now is where we hope for good snow cover and moderate winter temperatures so the 2014/15 winter wheat crop can overwinter and emerge in spring in excellent condition!  To help you with spring assessment of winter survival and crop life, record the following over the winter:

  1. crop’s condition such as crop stage and stand prior to snow cover.  Also note well acclimated plants will hold leaves close to the ground.
  2. winter stresses such as cold snaps, when they occurred and their duration,
  3. length and timing of snow cover. For winter survival, February/March snow cover is the best.

 

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD

To learn more on potential impacts of fall growth stages on winter wheat production factors, please visit MAFRD’s website at: http://www.gov.mb.ca/agriculture/crops/production/what-happens-if-my-winter-wheat-did-not-emerge-.html

 

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Preparing Unseeded Acres for Winter Wheat

Producers that have been unable to seed an annual crop this spring due to excess moisture conditions may want to consider preparing a portion of their land for winter wheat seeding this fall.

The key to successful winter wheat production is winter survival. The most successful management factor to help ensure winter survival is seeding into standing stubble that will catch and hold snow.  This is something that was evident the spring of 2014 where generally winter wheat seeded into good standing stubble survived the winter better than those fields that had poor stubble and therefore poor snow catch.

The following article was originally written by John Heard, Crop Nutrition Specialist with MAFRD in 2005, then updated in 2011 and now again in 2014.

Preparing Unseeded Acres for Winter Wheat Seeding – July 2014

For additional information on winter wheat production, visit MAFRD’s website at http://www.gov.mb.ca/agriculture/crops/production/winter-wheat.html

Submitted by: Pam de Rocquigny, MAFRD Cereal Crops Specialist

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Managing Winter Wheat Fields with Variable Plant Stands

Reports coming in across Manitoba indicates winter wheat survival ranges from excellent to poor.  In talking with some agronomists, those fields that did not have adequate stubble (density and height) and therefore poor snow cover are faring the worse.  Seeding date also seems to be playing a role where the later seeded fields are also impacted by winterkill or injury.

What is an Optimum Plant Stand?  An optimum winter wheat plant stand consists of 20-30 plants per square foot. But there is good yield potential with a less than optimum plant stand.  Check out the following post on CropChatter “Winter Wheat Stand Assessments” at http://cropchatter.com/winter-wheat-stand-assessments/

What if I Have a Field with Small Patches of Poor Stands?  For fields with small patches of poor stands, the best option is to leave the field and focus on management strategies such as controlling broadleaf and grassy weeds in a weed control program, early application of nitrogen to encourage tillering, and increase disease scouting since weakened plants may be delayed in growth leading to increased risk of rust and fusarium head blight infection.

What if My Field Has Large Patches of Poor Stands?  If you have fields with larger patches with few or no plants, decisions become more difficult. The first option is to keep the field and adjust your management based on the thin stand. Farmers will have to make hard decisions on what further inputs to put into the crop. Fungicide applications for foliar disease and fusarium head blight may not pencil out at reduced yield potential.

To help manage the larger patches, a possible option may be to plant winter wheat into the larger gaps. Winter wheat planted in the spring will not vernalize so it will not produce a head. However, it will provide ground cover and compete with weeds until harvest.

For winter wheat fields whose stand is extremely variable with large patches of dead or weakened plants, replanting may become a more realistic option. If you are considering reseeding and before destroying any wheat fields, you will need to contact your local MASC insurance agent. For more information on winter wheat insurance information, please visit MASC’s website at: http://www.masc.mb.ca/masc.nsf/program_winter_wheat.html

There is also additional information on Crop Chatter if faced with re-seeding:

Submitted by:  Pam de Rocquigny, MAFRD Provincial Cereal Crops Specialist

 

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What are my options if my winter wheat does not germinate this fall?

Poor emergence or plant stands are leaving many producers wondering if their winter wheat crop will survive the winter, what type of stands they might expect in the spring, and whether the crop will undergo the necessary processes to produce a head next year.   Unfortunately at this stage there isn’t much that can be done except understand the potential impact to crop production if the crop didn’t emerge or has just emerged.

The stage of crop development in the fall influences not only winter survival and yield potential but also crop competitiveness, maturity and the risk of infection with diseases such as rust and fusarium head blight (see Table 1 below).

Table 1:  Potential impacts of fall growth stages on winter wheat production factors

Growth Stage

Date of Germination

Yield Factor

Competition Factor*

Relative Maturity

3 leaf & tiller

Sept 5

100%

5

0 days

1-2 leaf

Sept 15

90-100%

4

+ 4

Sprouted

(not emerged)

Oct 1

80-100%

2

+ 8

Not germinated (imbibed)

Oct 15

60-100%

1

+ 10

* Competition factor: 5 = most competitive, 1 = least competitive

As the table illustrates, there may be minimal impact to yield potential of a crop that didn’t emerge in the fall but maturity will likely be delayed.  Crop competitiveness may be decreased so early season nitrogen application to encourage tillering, as well as timely weed control, will be very important.

In regards to vernalization concerns and whether the crop will produce heads next year, the key points to remember are:

  • Neither fall 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.
  • Vernalization may also occur under cool spring conditions.

If next spring winter wheat fields whose stands are extremely variable with large patches of dead or weakened plants, replanting may become a more realistic option.  If you are considering reseeding and before destroying any wheat fields, you will need to contact your local MASC insurance agent.  For more information on winter wheat insurance information, please visit MASC’s website at: http://www.masc.mb.ca/masc.nsf/program_winter_wheat.html

There are numerous articles on MAFRI’s site dealing with dry conditions and poor germination, including “What Happens if my Winter Wheat did not Emerge?”, “Spring Germinating Winter Wheat” and “Concerned About Your Winter Wheat Stand?”.  For more information on winter wheat production, please visit MAFRD’s website at: http://www.gov.mb.ca/agriculture/crops/production/winter-wheat.html

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD

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