Economics & Agronomics – Crop Management Decisions Need Both!

It’s an obvious statement to say successful farm management decisions need both agronomic and economic considerations. Farmers weigh out input cost versus the benefit to yield and quality of grain before making the decisions to buy and use new or additional products.

 Agronomy and economic crop management goes much beyond inputs. Consideration of crop rotation, Cost of Production, seeding date and weather indicators for disease all need to be considered. Within agronomic decisions there can be tools to estimate the economic impacts of different decisions. The ‘My Farm’, ‘Cost of Production’, ‘Canola Reseed Calculator’ and ‘Sclerotinia Treatment Decision Tool’ are all based on yield trends and agronomy to help make economic decisions easier.

See slideshow at http://www.gov.mb.ca/agriculture/business-and-economics/financial-management/pubs/presentation-mac-agronomicseconomics.pdf

Submitted by Roy Arnott – Farm Business Management, Killarney and Anastasia Kubinec – Crops Branch, Carman.

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Minimum Temperature Maps – May 13, 14, 15 & 16

Across many areas of Manitoba, frost was recorded over several evenings. Manitoba Agriculture’s Ag Weather Program has created minimum low temperature maps.  Frost was recorded across Manitoba in the early morning of May 13th.  However, the following early morning of May 14th saw temperatures drop to -7C in some areas of Central Manitoba.

MinT0513

MinT0514

Following are links to all four minimum temperature maps in pdf format:

Follow Manitoba Agriculture on Twitter at @MBGovAg

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The Potential Impact of Spring Frost on Winter Wheat

With the forecasted cooler overnight temperatures, here is a refresher on the potential impact spring frost can have on winter wheat crops in Manitoba. (Hopefully, we won’t have a need for this post!).  Currently, winter wheat acres range in development from tillering to stem elongation.

For winter wheat at tillering stage, plants can withstand very low temperatures for a period of time (-11°C for less than 2 hours). Frost damaged winter wheat at this stage will have leaf chlorosis and necrotic leaf tips. However, the effect on yield will be slight.

For winter wheat at jointing stage (stem elongation), plants can tolerate temperatures of -4°C for less than 2 hours.  Frost injury symptoms could include a dead leaf appearing in the whorl if the growing point was damaged, leaf yellowing or burning, or splitting or bending of the lower stem.  The impact to yield can range from moderate to severe, and lodging can also occur later in the season if stems were damaged.

For winter wheat at the boot stage, plants can tolerate temperatures of -2°C for less than 2 hours.  Frost injury symptoms in winter wheat (or even fall rye) can include spikes being trapped inside the boot and they may not emerge normally, spikes may emerge but may remain yellow or even white (sometimes only portions of the head may be impacted), awns may be twisted and you may see floret sterility resulting in poor kernel set and low grain yield.

In 2012, we did see winter wheat crops impacted by frost.  A frost event occurred May 30 when some winter wheat acres were at the early flag emergence stage.  When the spikes started to emerge, injury symptoms were noted.  In the photo below (taken by Ingrid Kristjanson, MAFRD),  you will note frost injury symptoms of twisted awns and incomplete kernel set.

Frost damaged winter wheat - ingrid

Frost Damaged Winter Wheat; Frost was Recorded May 30 at Early Flag Leaf Stage (2012) – Photo by Ingrid Kristjanson, Manitoba Agriculture

In Manitoba Agriculture’s June 3, 2015 webinar (available on YouTube at http://youtu.be/UDa3uWMmZzg), I covered some of the basics of frost injury symptoms in winter cereal crops and what to look for in terms of recovery.

For more information on frost damage in winter cereals and other crop types, please refer to Manitoba Agriculture’s Spring Frost Damage Bulletin.

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

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Will my early seeded wheat survive the forecasted cold snap?

With the forecasted cool temperatures, perhaps a quick refresher is needed for the potential impact on Manitoba’s spring cereal crops.

Spring cereals such as wheat, barley and oats are very tolerant to temperatures as low as -6°C since the growing point is below the soil surface until the 5 leaf stage to jointing.  In the May 21, 2015 NDSU Crop & Pest Report, Joel Ransom who is the Extension Agronomist for Cereal Crops, wrote there is “variation for tolerance between crops, however. In general terms for the cereals grown in ND (and provided they are at the same stage of development), tolerance to freezing temperatures can be ranked in the following order: winter rye (most tolerant to frost) > winter wheat > oats > barley > wheat > corn (least tolerant).”

Frost damaged spring cereals will have wilted, dark green and discolored leaves and will become necrotic at the leaf tips within 1 or 2 days after freezing. However, new leaf growth (normal green color) from the growing point should follow within 2-3 days. However, it can be upwards of 5 days if growing conditions remain cool after the frost event.

Fortunately, majority of emerged spring wheat, oats and barley acres in Manitoba are in the 1 to 3 leaf stages of development where the growing point is still below ground and therefore protected from the cool air temperatures.

For cereal acres that have recently been planted, but haven’t emerged, there is often concern cold and freezing temperatures can kill sprouted seed. In a 2015 article by Jochum Weirsma (University of Minnesota), he reports “literature has shown that sprouted wheat and young seedling will likely survive temperatures in the low twenties (20F = -6.7C).  A quick first check of the color of radicle (first root) and coleoptile (first leaf) is the first step: a white and firm radicle and coleoptile will indicate that the sprout is not damaged by frost after the seed has been allowed to thaw out. A second test to determine viability of seed is to dig up seed and bring it home, place it between moist paper towels, and keep it at room temperature.  If the seed is viable the sprouts should start to grow within 24 hours.”

And remember, temperature and crop type are only two factors that play a role in determining the impact of spring frosts – duration of temperatures, other weather conditions, soil moisture and residue cover can also have an impact.

More additional information on frost damage, refer to Manitoba Agriculture’s Spring Frost Damage Bulletin or the Crop Chatter post Effect of Spring Frost on Emerging Crops.

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

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Impact of Frost on Winter Wheat & Fall Rye

The May 30th frost had the potential to impact winter wheat and fall rye crops in Manitoba as some may have been in crop stages more sensitive to freezing temperatures.  In MAFRD’s June 3 webinar (available on YouTube at http://youtu.be/UDa3uWMmZzg), I covered some of the basics of frost injury symptoms in winter cereal crops and what to look for in terms of recovery.  The more vulnerable growth stages are either the jointing (stem elongation) or boot stage of development.

For winter wheat at jointing stage, plants can tolerate temperatures of -4°C for less than 2 hours.  In areas of Manitoba, these temperatures may have been achieved along with some acres at the jointing stage, but whether the duration was long enough is unclear so scouting will be important over the coming days/weeks. Frost injury symptoms could include a dead leaf appearing in the whorl if the growing point was damaged, leaf yellowing or burning, or splitting or bending of the lower stem.  The impact to yield can range from moderate to severe, and lodging can also occur later in the season if stems were damaged.

For winter wheat at the boot stage, plants can tolerate temperatures of -2°C for less than 2 hours.  There may have been limited acres at this growth stage for winter wheat. However, it is possible some fall rye acres were at the boot stage, and in many areas temperatures did fall below -2°C for more than 2 hours.  Frost injury symptoms in either crop can include spikes being trapped inside the boot and they may not emerge normally, spikes may emerge but may remain yellow or even white (sometimes only portions of the head may be impacted), awns may be twisted and you may see floret sterility resulting in poor kernel set and low grain yield.

In 2012, we did see winter wheat crops impacted by frost.  A frost event occurred May 30 when some winter wheat acres were at the early flag emergence stage.  When the spikes started to emerge, injury symptoms were noted.  In the photo below (taken by Ingrid Kristjanson, MAFRD),  you will note frost injury symptoms of twisted awns and incomplete kernel set.

Frost damaged winter wheat - ingrid

Frost Damaged Winter Wheat; Frost was Recorded May 30 at Early Flag Leaf Stage (2012) – Photo by Ingrid Kristjanson, MAFRD

For more information on frost damage in winter cereals and other crop types, please refer to MAFRD’s Spring Frost Damage Bulletin.

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

 

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Cereal Crops Recovering from Frost Injury

The May 30th frost impacted spring cereal crops across Manitoba. Fortunately, majority of spring wheat, oats and barley were at the tillering stages of development where the growing point is still below ground and therefore protected from the cool air temperatures (the growing point moves above ground at jointing or stem elongation).

However, this doesn’t mean cereal crops escaped without some symptoms of injury.  In MAFRD’s June 3 webinar (available on YouTube at http://youtu.be/UDa3uWMmZzg), I covered some of the basics of frost injury symptoms in cereal crops and what to look for in terms of recovery. (And for those interested in canola and flax, my colleague Anastasia Kubinec of MAFRD covered some excellent material for those crop types in the same webinar).

For cereals, you want to look for new leaf growth (normal green color) from the growing point that should follow within 2 to 3 days after the frost event. It can go upwards of 5 days if growing conditions are cool.  Below is a great photo by Lionel Kaskiw with MAFRD which shows barley impacted by frost recovering.  You’ll also notice the water-soaked appearance of some of the older leaves, a classic symptom of frost injury.

Frost Damaged Barley

Frost-Damaged Barley Recovering; Note New Leaf Growth Emerging from the Growing Point – Photo by Lionel Kaskiw, MAFRD (2015)

Fortunately, the loss of leaf tissue at this early stage should have little impact on yield.  But be cautious when applying herbicides in the coming days.  Generally, you want to wait for at least 48 hours after the frost event, as well as seeing the crop resuming growth.  However, please check with your local chemical representative in terms of when it should be safe to apply herbicides after a frost event as it can be product-specific.

More additional information on frost damage, refer to MAFRD’s Spring Frost Damage Bulletin.

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

 

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Assessing Spring Frost Damage after Corn Emergence

Although there isn’t many acres of emerged corn in Manitoba, some corn has emerged and was recently impacted by the weekend’s frost events.

Corn in the V5 stage (5 leaves with collars showing) or less will recover from light frosts because the growing point is still below the soil surface.  Symptoms of frost damage will start to show up about 1 to 2 days after a frost. Symptoms are water soaked leaves (see Figure 1) that eventually turn brown and necrotic. Frost will often kill young corn leaves but plants, even with extensive leaf damage, will likely recover if the growing point was not injured. The death of leaf tissue above the growing point has only a small effect on corn growth and yield at early stages of development.

While extremely rare, if air temperatures drop to temperatures of -2°C or less for more than a few hours, the growing point region of a young corn plant can be injured or killed even if it is still below the soil surface.

frosted corn 2009

Figure 1: Frost Damaged Corn. Photo by Pam de Rocquigny (2009)

To assess corn plants, look at the growing point approximately 3 to 5 days after the frost occurred.  By this time, surviving corn plants should be showing new leaf tissue expanding from the whorls (see Figure 2).  Note, it is not unusual for the new leaves to get ‘caught up’ in the dead leaf tissue.  You can also check the growing point, which can be found by pulling up the entire corn plant, including roots, and splitting the entire plant lengthwise. If the growing point is white or creamy in appearance injury didn’t occur.  However, damaged tissue in the growing point region will be discolored and soft or “water-soaked”. There will also be lack of new regrowth from the whorl.

Frosted Corn CDS 2009 Day 6 (2)

Figure 1: Frost Damaged Corn, 6 Days after Frost Event. Photo by Pam de Rocquigny (2009)

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

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Getting What You Expect Out of Your Herbicide – Part 1: Cold Spring Weather

Submitted by Anastasia Kubinec, MAFRD Oilseed Crop Specialist

As seeding and spraying collide, for pre-seed burn off and winter cereals in-crop applications, here are some tips for early applications to get the best performance out of your herbicides. Part 1 is only covering the pre-seed herbicide options and the types of products that would be used on winter cereals.

  • Spray when weeds are actively growing
  • Spray when the temperatures are at least 150C
  • Use the water volume stated on the label
  • Use the surfactant or adjuvant included or recommended
  • Watch and follow the rain free period

Some of the herbicides that work well under cool conditions are:

  • Most Group 4 herbicides
  • Most of the residual herbicides of any group
  • “Fop” group 1 herbicides (ex. Horizon)
  • Carfentrazone (ex. CleanStart, Aim)

Frost and Spraying

Actual temperature and duration of the frost will impact plant growth, how well the herbicide will work and crop safety. For most Group 1 and Group 2 herbicides, it is better to wait at least 48 hours before application to allow weeds and the crop to recoup and start actively growing.

For pre-seed glyphosate, after a light frost (0 to -2°C), spraying could resume 24 hours later, but temperatures need to go up. Avoid spraying until the temperature is above 8°C….the closer it is to 150C and above, the better the control. If a harder frost occurs, avoid spraying for 48 hours and assess the damage on the target weeds. You want to see that plants are still green and actively growing, and daytime temperatures are warming up.

Frost occurring within 24 hours after spraying can also impact control.

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Effect of Spring Frost on Emerging Crops

Submitted by Anastasia Kubinec, Manitoba Agriculture, Oilseeds Crop Specialist

Originally posted May 8th and 30th, 2015…..re-post May 13, 2016.

Don’t assume because there is frost (or snow) on the ground, that your emerging crop in dead!

With the drop in temperatures in the past couple of days, there are a few things to keep in mind if the mercury dips below 0°C. The temperature is the instigator for causing frost, but whether it is -0.1°C or -4°C the damage inflicted is highly influenced on these other factors:

  1. Duration
    • Short frost = < 2 hours,  may not cause much damage if frost is light (above -1 to -2°C), crop type and staging is tolerant, conditions wet and crop has become acclimatized.
    • Short frost = < 2 hours, but hard frost (lower than -2°C), crops like canola are more sensitive to longer frost vs. cereals, damage can be variable in field and across area.
    • Long frost = > 2 hours, whether frost is light or hard the longer the negative temperatures the more time for damage to happen.  Tolerance by crop type varies.
  2. Other Environmental Conditions
    • Cloudy and wet – prior to a frost, cool temperatures slow plant growth and ‘hardens’ plants off, which will help them tolerate a frost.  Also wet soil helps buffer the cold air effects on the plants, as wet soils change temperature slower than dry soils.
    • Sunny and dry – The combination of a  dramatic drop in air temperatures when plants are actively growing then a brilliant sunny day after the frost event is where we have seen the most damage.  Scouting after the frost (24 and 48 hours) is very important though to assess extent and percentage of field injury.
    • Field trash cover – increased trash in fields was seen to increase frost damage on very susceptible crops in the 2009 June frost
  3. Crop Type
    • Spring Cereals – more tolerant than other crops types, can tolerant to temperatures as low as -6°C as growing point below ground until the 5 leaf stage.
    • Winter Wheat – can withstand very low temperatures for a short period of time (-11°C for less than 2 hours) up until the tillering stage.
    • Corn – smaller then V5, will recover from light frost as growing point below ground. Leaves probably will be killed, but plants will recover if the growing point ok.
    • Oilseeds – environmental conditions impact frost severity on susceptible canola and flax cotyledons. Resiliency increases at the 3-4 leaf stage (canola) or 2nd whorl (flax).  Sunflowers are fairly tolerant  up to the V4 stage.
    • Pulses – peas are most tolerant, then soybean, edibles bean are very susceptible even before emergence.   Field pea crops are rarely lost to frost. Soybean are more sensitive, but the smaller the soybean plant the more tolerant they are  – from emergence to cotyledon can withstand short light frosts.

Scouting After a Frost

Scouting should start 24 – 48 hours after the frost and continue for the 5 days following the frost event.  Look for leaves wilting, looking “water-soaked” or see “frost banding”.  Watch for new growth in the plant.  You do not want to see plants wilted and not perking back up or pinching off on the stem near the growing point (canola, flax, soybeans).  Also assess the area affected by frost, small areas or a few plants damaged are ok, as other plants emerged (or just emerging) will fill in those spaces.  Large dead areas may need to be re-seeded.

If in doubt of what look for, call your local agronomists, local FPE Specialist with Manitoba Agriculture or the Crop Industry Branch.

For more specific details on what actually occurs to plants with a frost and crop specific details and symptoms to look for (and how long after a frost to do assessment) see Manitoba Agriculture’s Spring Frost Damage Bulletin.

 

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Should I Still Be Concerned About a Spring Frost?

Spring frost is something that producers need to consider into late May and in some areas of Manitoba, there is an elevated risk of occurence into the month of June.

Average Date of last Spring Frost – is considered after May 19th.  In the  Portage la Prairie, Langruth, Pilot Mound, Morden and Altona regions there is less than a 50 percent chance that frost will occur after the 19th. In other areas, the last spring frost occurs, on average, after May 24. On higher elevations, central Interlake and the south-eastern regions of Manitoba can expect frost during the first week of June in one out of every two years.  Figure 1: Manitoba Average Last Spring Frost

1 in 4 year risk– that the last frost will occur about eight days later than average. This means a 25 % risk that the last spring frost will occur after May 24 in the Portage la Prairie and Altona regions. In most other regions of Manitoba, a 25% risk of a spring frost in the first week of June and in the Riding Mountain and Hodgson regions, that is will occur later than mid-June.  Figure 2: Manitoba Last Spring Frost (1 in 4 years)

1 in 10 year risk – a 10% risk that the last spring frost will occur later than June 3 for most regions.  A recent example of this is in 2009, when there was a wide spread frost through the agricultural growing region on June 6th.  Figure 3: Manitoba Last Spring Frost (1 in 10 years)

If a frost does occur, please refer to MAFRI`s Spring Frost Damage Bulletin to help assess the situation at http://www.gov.mb.ca/agriculture/crops/cropproduction/faa23s00.html

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