Freeze Event Across Oklahoma: What Wheat Growers Should Look For in the Next Few Days

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Temperatures dropped below freezing across parts of the state. Here is how growth stage, temperature, and duration of the freeze influence potential wheat injury.

Amanda de Oliveira Silva, Small Grains Extension Specialist

Several areas across Oklahoma experienced freezing temperatures overnight, with some locations recording multiple hours below freezing (Figures 1 and 2). There is potential for freeze injury, especially in drought-stressed wheat that has reached jointing or later growth stages. If wheat is still before jointing, the growing point remains below the soil surface and is more protected from freezing injury.

However, with the warm conditions we experienced earlier this spring, the crop is running slightly ahead of schedule, and some fields have already reached or passed the jointing stage. At this stage, the developing head has started to move up the elongating stem and is no longer protected.

In the coming days we may start to see additional symptoms of freeze injury. The extent of the injury will depend on several factors, including the growth stage of the plants, how low the temperature dropped, and how long temperatures remained at those levels. Brief freezes often cause little damage, but several hours below critical temperatures during jointing or reproductive stages can reduce yield (Figure 3).

Figure 1. Minimum air temperature (in Fahrenheit) over the past 24 hours at each Mesonet station. Figure courtesy Oklahoma Mesonet.
Figure 2. Number of hours spent at or below freezing (32°F) over the past 48 hours at Mesonet station. Figure courtesy Oklahoma Mesonet.

What are the temperatures that can damage the wheat plants?

The potential for freeze injury depends largely on the growth stage of the crop. Anecdotal evidence sometimes suggests varietal differences in resistance to spring freeze injury, but this is often due to differences in plant maturity at the time of the freeze event. Earlier-maturing varieties are more likely to be injured during spring freezes simply because they are typically more advanced in development.

The susceptibility of wheat plants to freeze injury steadily increases as the crop progresses from jointing to heading and flowering.

Figure 3 below provides a general guide to temperature thresholds and their potential impact on yield. Keep in mind that these values are not exact, but they serve as useful rules of thumb.

Temperatures closer to the soil surface may be slightly higher than those recorded by weather stations located about one meter above the ground, especially when soil moisture is present. Because each freeze event is unique, it is difficult to define exact thresholds. For example, a field at the jointing stage exposed to 24°F for two hours may experience similar injury to wheat exposed to 28°F for a longer period of time.

Figure 3. Temperatures that can cause injury to winter wheat at different growth stages. Source: Kansas State University publication C646: Spring Freeze Injury to Kansas Wheat.

How long should I wait to assess the injury?

Patience is important when evaluating freeze damage. The full extent of injury is usually not visible within the first day or two after the freeze event.

If warm temperatures return quickly, symptoms may become evident within 5–7 days. If temperatures remain cool, it may take 10–14 days before the extent of the injury can be properly assessed.

What freeze injury symptoms should I look for?

One common symptom is leaf tip burn, where leaf tips turn yellow and necrotic (Figure 4). This type of damage is often cosmetic and may not significantly affect yield.

More severe freeze damage may cause entire leaves to turn yellow or white, and plants may lose their turgidity and appear flaccid (Figure 5). In some cases, a “silage” smell may be noticeable several days after the freeze event.

Figure 4. Leaf tips that have turned necrotic due to freezing temperatures. Photo taken in March 2017 courtesy of Josh Bushong, OSU Northwest Area Extension Agronomist.
Figure 5. More severe freeze damage causing leaves to turn yellow-white and plants to lose turgidity. Source: Kansas State University publication C646: Spring Freeze Injury to Kansas Wheat.

The most important plant part to check: the developing head (growing point)

This is particularly important in areas where fields are more advanced in growth. Plants may appear healthy overall while the developing head has been damaged or killed.

To examine the growing point, carefully slice the stem lengthwise. A healthy growing point will have a firm, whitish-green appearance and remain turgid (Figures 6 and 7, left). Often you can lightly flick the head; if it bounces back and does not break, it is likely still healthy.

If the growing point is mushy, limp, breaks easily, or appears brown, it has likely been compromised (Figure 7, right). Another indication of damage is when the next emerging leaf becomes necrotic and lower stems appear discolored with lesions or enlarged nodes.

Figure 6. Close up of a healthy wheat head (growing point) above the second node showing  whitish-green color and turgidity.
Figure 7. Plants that appear healthy may still have damaged heads. The photo on the left shows a healthy head, while the photo on the right shows a freeze-damaged head.

Freeze injury at later growth stages

Freezing temperatures at the boot stage may cause the head to become trapped in the flag leaf sheath, preventing proper head emergence (Figure 8). Whitish awn tips are often an indication that the head was exposed to freezing temperatures and that the flower parts may have been damaged.

Freezes during flowering may cause sterility due to damage to the anthers (the male reproductive organ), resulting in poor kernel set and yield losses (Figure 9).

Figure 8. Freeze injury at the boot stage may cause heads to remain trapped in the boot.
Figure 9. Freeze during flowering may cause sterility due to damage to the anthers, resulting in poor kernel set and yield loss.

Can wheat recover from freeze injury?

The percentage of damaged heads does not always translate directly into yield loss. At the jointing stage, wheat still has the potential to produce additional tillers or retain secondary tillers.

Whether these tillers can compensate for damaged primary tillers will depend on subsequent weather conditions. If growing conditions are favorable, late-emerging tillers may still produce grain. However, if the crop is already near flowering or later stages, recovery becomes much more limited.

Key points to keep in mind

• Every freeze event is unique. Injury must be evaluated on a field-by-field basis. Temperature thresholds are guidelines, not exact predictors of damage. In some cases, conditions may suggest severe injury but fields recover with minimal impact.

• The extent of injury depends on several factors, including growth stage, minimum temperature reached, and duration of freezing temperatures. Field conditions such as elevation, residue cover, and soil moisture can also influence canopy temperatures.

• Symptoms may take several days to appear. Damage may become noticeable over the next days or into the middle of next week. Healthy wheat heads will remain firm and green, while damaged heads may appear bleached, yellow, or brown and break easily when pressed.

Stay Connected!

Enroll in the OSU Wheat text update service by texting the word “wheat” to (855) 452-0486 to receive timely information throughout the wheat season.

If you start to observe freeze injury in your fields over the next several days, send us a text and let us know what you are seeing.

Additional Resources

Contact your local Extension office.

C646: Spring Freeze Injury to Kansas Wheat.

Check Your Wheat: Greenbugs Reported in Central Oklahoma

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Ashleigh M. Faris, Cropping Systems Extension Entomologist

Wheat producers in central Oklahoma are reporting the presence of the greenbug,Schizaphis graminum, in winter wheat fields. Greenbugs are one of the most important insect pests of wheat in the southern Great Plains and can occur from fall through spring. These aphids feed on plant sap and inject toxins into wheat plants, causing characteristic leaf discoloration and plant injury.

Early detection through field scouting is essential to determine whether populations are increasing and if an insecticide treatment is justified.

Greenbug Identification & Biology

Key identifying characteristics of greenbug (Figure 1):

  • Small aphids (~1/16 inch long)
  • Pale to lime-green body
  • Dark green stripe down the middle of the back
  • Dark tips on antennae and legs
  • Found in colonies on the underside of wheat leaves
Figure 1. Greenbug nymphs and adults on wheat leaf. Greenbugs are distinguishable from other aphids based on their lime green bodies, dark green stripe down back, dark antennae, and dark leg tips. Image courtesy of https://databases.nbair.res.in/.

Greenbugs reproduce rapidly under favorable conditions (between 55° F and 95° F) and often occur in patches within fields rather than evenly distributed populations. During periods of cool weather, the greenbug may increase to enormous numbers, due to the absence of natural enemies, which develop significantly slower compared to greenbugs at such temperatures. On the other hand, cold weather can also influence aphid populations. However, this latest cold snap is not enough to eliminate greenbugs. It takes average temperatures below 20° F for at least a week to kill a substantial number of greenbugs in wheat.

Greenbug Damage in Wheat

Greenbugs damage wheat in two ways, through direct feeding and injection of toxic saliva. Greenbugs may also transmit barley yellow dwarf virus (BYDV), which can further reduce yield potential.

Typical early symptoms include small, reddish or copper spots on leaves (Figure 2) and yellowing around feeding sites. Advanced infestations will result in leaves turning yellow or orange, dead leaf tissue, stunted plants, and expanding patches of dead wheat. Heavy infestations may kill seedlings and reduce tillering, particularly during drought stress.

Figure 2. Early damage to wheat caused by greenbugs appears as yellow to reddish, coppery spots. Image courtesy of Alton Sparks, Kansas State Extension.

How to Scout for Greenbugs

The Glance-N-Go™ sampling system developed by Oklahoma State University can help determine whether aphid populations exceed economic thresholds. Download the Greenbug Glance N’ Go Sampler app for your smartphone. You will then input the control cost ($/Acre), crop value ($/Acre), and the Spring sampling window. Use a zig-zag or W-pattern (Figure 3) to scout your field, checking undersides of leaves at three tillers per stop for greenbugs and brown mummies. Use the app to record the numbers of these insects and sample until the app tells you to stop sampling or tells you treat. As temperatures warm, continue to scout regularly as greenbug populations may build.

Figure 3. Scouting pattern for greenbug. Walk a W-pattern across the field and examine plants at multiple locations. Inspect the underside of leaves and base of tillers for aphids and beneficial insects. Image courtesy of A.M. Faris, Oklahoma State University Extension.

Scouting recommendations without the Greenbug Glance N’ Go Sampler app:

  1. Walk a W or zigzag pattern across the field.
  2. Examine 10–20 plants at each stop.
  3. Check:
    • Underside of leaves
    • Leaf midrib
    • Base of tillers
  4. Record:
    • Aphids per tiller
    • Presence of aphid mummies (Figure 4)
    • Beneficial insects

Beneficial Insects

Natural enemies frequently control aphid populations. While scouting for greenbug you should also look for lady beetles, lacewing larvae, hoverfly larvae, and parasitized aphids (“mummies”) (Figure 4). If beneficial insects are abundant, aphid populations may decline without insecticide treatment. Where there are one to two lady beetles (adults and larvae) per foot of row, or 15 to 20 percent of the greenbugs have been parasitized, control measures could be delayed until it is determined whether the greenbug population is continuing to increase.

Based on current wheat scouting, it appears that parasitoid numbers are low this 2026 season so continuing to scout for greenbug will be critical in responding to populations that go unchecked by beneficials.

Figure 4. Brown mummy amongst greenbugs. The brown, inflated insect in the top let of the image is a greenbug that has been parasitized. Look for these mummies when making management decisions. Image courtesy of David Voegtlin, University of Illinois.

Economic Threshold Guidelines

The simplest way to determine if action needs to be taken against greenbugs is to utilize the Glance-N-Go™ sampling system developed by Oklahoma State University. Approximate guidelines historically used in Oklahoma wheat can be found in Table 1 below.

Table 1. Approximate guidelines historically used in Oklahoma wheat for greenbug.

Wheat Growth Stage# Greenbugs per Linear Foot
Seedling wheat50
3–6-inch wheat, 3 tillers or more100 – 300
Late vegetative wheat300 to 500

Thresholds are influenced by:

  • Wheat growth stage
  • Crop value
  • Cost of treatment
  • Presence of beneficial insects

Insecticides Labeled for Greenbugs in Wheat

Aphid feeding and insecticide performance are strongly influenced by temperature. Greenbugs tend to move higher on wheat plants during warm conditions but may move lower on the plant or below ground during cold weather, reducing exposure to insecticides. As a result, damaging populations are most often observed in late winter and early spring. Insecticides generally perform best when temperatures are above 50°F, and control may occur more slowly in cooler conditions (e.g., control at 45° F may take roughly twice as long as at 70° F). If applications must be made under cooler temperatures, use the highest labeled rate. Wheat grown under irrigation can typically tolerate higher greenbug populations than dryland wheat.

Table 2. Common foliar options for greenbug in winter wheat.

Active IngredientExample Trade Names
Dimethoate*Dimethoate 4E
Chlorantraniliprole + Lambda-cyhalothrinBeseige*
Lambda-cyhalothrinWarrior II*
Gamma-cyhalothrinProaxis*, Declare
Zeta-cypermethrinMustang Maxx
SulfoxaflorTransform WG
FlupyradifuroneSivanto Prime
*Greenbug is known to have many biotypes. Besiege and Proaxis Insecticides may provide suppression only. Use the maximum rate when treating greenbug.

Always follow pesticide label directions, application sites, and rates. Be sure to read and follow the label for preharvest intervals (PHI) and restricted-entry intervals (REI). Use a minimum of 10 GPA by ground and 3 GPA by air (if labelled for aerial application) to ensure adequate coverage.

For assistance with aphid identification or treatment decisions, see OSU Fact Sheet EPP-7099 Small Grain Aphids in Oklahoma and Their Management, or contact your local OSU Extension office.

First Hollow Stem Update – 3/13/2026

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Amanda de Oliveira Silva, Small Grains Extension Specialist

The first hollow stem stage indicates the beginning of stem elongation or just before the jointing stage. It is a good indicator of when producers should remove cattle from wheat pasture. This occurs when there is 1.5 cm (5/8”, or the diameter of a dime) of hollow stem below the developing grain head (see full explanation). 

The latest FHS results from OSU forage trials in Stillwater (Table 1) and Chickasha (Table 2) are listed below. For an additional resource and wheat update on FHS, see the Mesonet First Hollow Stem Advisor. 

OSU Small Grains Program monitors FHS occurrence on a twice-per-week basis

As in previous years, we will continue monitoring FHS occurrence in our wheat plots at Stillwater and Chickasha and share updates on this blog. In past years, our forage trials—where FHS samples are collected—were seeded early to simulate a grazed system, though forage was not removed. This method created an accelerated growth environment, allowing us to identify the earliest onset of FHS. Varieties that reach FHS earliest in these trials should be closely monitored in commercial fields.

This year, we are continuing with a new approach by simulating grazing with a mower in the forage trial in Stillwater. This will allow us to compare whether varieties reach FHS at different times when grazed versus non-grazed. We hypothesize that the simulated grazing treatment will likely delay FHS relative to the non-grazed treatment, with FHS differences among varieties becoming less pronounced. We also hypothesize that the amount of delay will vary among varieties, such that an early-FHS variety in the non-grazed environment may appear more intermediate in its FHS arrival with canopy removal. This comparison will provide insight into how canopy removal from grazing impacts the timing of reproductive development.

The latest FHS results for each variety planted in our forage trials at Stillwater and Chickasha are summarized below (Tables 1 and 2). All varieties have reached the 1.5 cm FHS threshold.

Table 1. First Hollow Stem (FHS) results for each wheat variety collected at Stillwater. Plots were planted on 10/10/2025, with one section left unclipped and the other clipped to simulate grazing. The FHS threshold is 1.5 cm (5/8″ or approximately the diameter of a dime). Reported values represent the average of ten measurements per variety. Varieties that exceed the threshold are highlighted in red. For the simulated grazing, plots were mowed on January 2nd and 13th, and on February 9th and 16th at a 3” cutting height, with the frequency representing a light grazing treatment.

Table 2. First Hollow Stem (FHS) results for each wheat variety collected at Chickasha. Plots were planted on 9/25/2025, with all sections left unclipped (i.e., not grazed). The FHS threshold is 1.5 cm (5/8″ or approximately the diameter of a dime). Reported values represent the average of ten measurements per variety. Varieties that exceed the threshold are highlighted in red.

Contact your local Extension office and us if you have questions. 

Additional resources available:

Acknowledgments: 

Tyler Lynch, Senior Agriculturalist

Francisco H. Aispuro Arana, Graduate Research Assistant

Israel Molina Cyrineu, Graduate Research Assistant

Yanina Correndo, Graduate Research Assistant

Juan Bautista Bruno, Visiting scholar

Ana Sarah Silveira Barbosa, Visiting scholar

First Hollow Stem Update – 3/5/2026

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Amanda de Oliveira Silva, Small Grains Extension Specialist

The first hollow stem stage indicates the beginning of stem elongation or just before the jointing stage. It is a good indicator of when producers should remove cattle from wheat pasture. This occurs when there is 1.5 cm (5/8”, or the diameter of a dime) of hollow stem below the developing grain head (see full explanation). 

The latest FHS results from OSU forage trials in Stillwater (Table 1) and Chickasha (Table 2) are listed below. For an additional resource and wheat update on FHS, see the Mesonet First Hollow Stem Advisor. 

OSU Small Grains Program monitors FHS occurrence on a twice-per-week basis

As in previous years, we will continue monitoring FHS occurrence in our wheat plots at Stillwater and Chickasha and share updates on this blog. In past years, our forage trials—where FHS samples are collected—were seeded early to simulate a grazed system, though forage was not removed. This method created an accelerated growth environment, allowing us to identify the earliest onset of FHS. Varieties that reach FHS earliest in these trials should be closely monitored in commercial fields.

This year, we are continuing with a new approach by simulating grazing with a mower in the forage trial in Stillwater. This will allow us to compare whether varieties reach FHS at different times when grazed versus non-grazed. We hypothesize that the simulated grazing treatment will likely delay FHS relative to the non-grazed treatment, with FHS differences among varieties becoming less pronounced. We also hypothesize that the amount of delay will vary among varieties, such that an early-FHS variety in the non-grazed environment may appear more intermediate in its FHS arrival with canopy removal. This comparison will provide insight into how canopy removal from grazing impacts the timing of reproductive development.

The latest FHS results for each variety planted in our forage trials at Stillwater and Chickasha are summarized below (Tables 1 and 2). Most varieties have reached the 1.5 cm FHS threshold.

Table 1. First Hollow Stem (FHS) results for each wheat variety collected at Stillwater. Plots were planted on 10/10/2025, with one section left unclipped and the other clipped to simulate grazing. The FHS threshold is 1.5 cm (5/8″ or approximately the diameter of a dime). Reported values represent the average of ten measurements per variety. Varieties that exceed the threshold are highlighted in red. For the simulated grazing, plots were mowed on January 2nd and 13th, and on February 9th and 16th at a 3” cutting height, with the frequency representing a light grazing treatment.

Table 2. First Hollow Stem (FHS) results for each wheat variety collected at Chickasha. Plots were planted on 9/25/2025, with all sections left unclipped (i.e., not grazed). The FHS threshold is 1.5 cm (5/8″ or approximately the diameter of a dime). Reported values represent the average of ten measurements per variety. Varieties that exceed the threshold are highlighted in red.

Contact your local Extension office and us if you have questions. 

Additional resources available:

Acknowledgments: 

Tyler Lynch, Senior Agriculturalist

Francisco H. Aispuro Arana, Graduate Research Assistant

Israel Molina Cyrineu, Graduate Research Assistant

Yanina Correndo, Graduate Research Assistant

Juan Bautista Bruno, Visiting scholar

Ana Sarah Silveira Barbosa, Visiting scholar

First Hollow Stem Update – 3/2/2026

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Amanda de Oliveira Silva, Small Grains Extension Specialist

The first hollow stem stage indicates the beginning of stem elongation or just before the jointing stage. It is a good indicator of when producers should remove cattle from wheat pasture. This occurs when there is 1.5 cm (5/8”, or the diameter of a dime) of hollow stem below the developing grain head (see full explanation). 

The latest FHS results from OSU forage trials in Stillwater (Table 1) and Chickasha (Table 2) are listed below. For an additional resource and wheat update on FHS, see the Mesonet First Hollow Stem Advisor. 

OSU Small Grains Program monitors FHS occurrence on a twice-per-week basis

As in previous years, we will continue monitoring FHS occurrence in our wheat plots at Stillwater and Chickasha and share updates on this blog. In past years, our forage trials—where FHS samples are collected—were seeded early to simulate a grazed system, though forage was not removed. This method created an accelerated growth environment, allowing us to identify the earliest onset of FHS. Varieties that reach FHS earliest in these trials should be closely monitored in commercial fields.

This year, we are continuing with a new approach by simulating grazing with a mower in the forage trial in Stillwater. This will allow us to compare whether varieties reach FHS at different times when grazed versus non-grazed. We hypothesize that the simulated grazing treatment will likely delay FHS relative to the non-grazed treatment, with FHS differences among varieties becoming less pronounced. We also hypothesize that the amount of delay will vary among varieties, such that an early-FHS variety in the non-grazed environment may appear more intermediate in its FHS arrival with canopy removal. This comparison will provide insight into how canopy removal from grazing impacts the timing of reproductive development.

The latest FHS results for each variety planted in our forage trials at Stillwater and Chickasha are summarized below (Tables 1 and 2). Some varieties have reached the 1.5 cm FHS threshold.

Table 1. First Hollow Stem (FHS) results for each wheat variety collected at Stillwater. Plots were planted on 10/10/2025, with one section left unclipped and the other clipped to simulate grazing. The FHS threshold is 1.5 cm (5/8″ or approximately the diameter of a dime). Reported values represent the average of ten measurements per variety. Varieties that exceed the threshold are highlighted in red. For the simulated grazing, plots were mowed on January 2nd and 13th, and on February 9th and 16th at a 3” cutting height, with the frequency representing a light grazing treatment.

 Table 2. First Hollow Stem (FHS) results for each wheat variety collected at Chickasha. Plots were planted on 9/25/2025, with all sections left unclipped (i.e., not grazed). The FHS threshold is 1.5 cm (5/8″ or approximately the diameter of a dime). Reported values represent the average of ten measurements per variety. Varieties that exceed the threshold are highlighted in red.

Contact your local Extension office and us if you have questions. 

Additional resources available:

Acknowledgments: 

Tyler Lynch, Senior Agriculturalist

Francisco H. Aispuro Arana, Graduate Research Assistant

Israel Molina Cyrineu, Graduate Research Assistant

Yanina Correndo, Graduate Research Assistant

Juan Bautista Bruno, Visiting scholar

Ana Sarah Silveira Barbosa, Visiting scholar

First Hollow Stem Update – 2/17/2026

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Amanda de Oliveira Silva, Small Grains Extension Specialist

The first hollow stem stage indicates the beginning of stem elongation or just before the jointing stage. It is a good indicator of when producers should remove cattle from wheat pasture. This occurs when there is 1.5 cm (5/8”, or the diameter of a dime) of hollow stem below the developing grain head (see full explanation). 

The latest FHS results from OSU forage trials in Stillwater (Table 1) and Chickasha (Table 2) are listed below. For an additional resource and wheat update on FHS, see the Mesonet First Hollow Stem Advisor. 

OSU Small Grains Program monitors FHS occurrence on a twice-per-week basis

As in previous years, we will continue monitoring FHS occurrence in our wheat plots at Stillwater and Chickasha and share updates on this blog. In past years, our forage trials—where FHS samples are collected—were seeded early to simulate a grazed system, though forage was not removed. This method created an accelerated growth environment, allowing us to identify the earliest onset of FHS. Varieties that reach FHS earliest in these trials should be closely monitored in commercial fields.

This year, we are continuing with a new approach by simulating grazing with a mower in the forage trial in Stillwater. This will allow us to compare whether varieties reach FHS at different times when grazed versus non-grazed. We hypothesize that the simulated grazing treatment will likely delay FHS relative to the non-grazed treatment, with FHS differences among varieties becoming less pronounced. We also hypothesize that the amount of delay will vary among varieties, such that an early-FHS variety in the non-grazed environment may appear more intermediate in its FHS arrival with canopy removal. This comparison will provide insight into how canopy removal from grazing impacts the timing of reproductive development.

The latest FHS results for each variety planted in our forage trials at Stillwater and Chickasha are summarized below (Tables 1 and 2). Most varieties are still well below the 1.5 cm FHS threshold.

Table 1. First Hollow Stem (FHS) results for each wheat variety collected at Stillwater. Plots were planted on 10/10/2025, with one section left unclipped and the other clipped to simulate grazing. The FHS threshold is 1.5 cm (5/8″ or approximately the diameter of a dime). Reported values represent the average of ten measurements per variety. Varieties that exceed the threshold are highlighted in red. For the simulated grazing, plots were mowed on January 2nd and 13th, and on February 9th and 16th at a 3” cutting height, with the frequency representing a light grazing treatment.

Table 2. First Hollow Stem (FHS) results for each wheat variety collected at Chickasha. Plots were planted on 9/25/2025, with all sections left unclipped (i.e., not grazed). The FHS threshold is 1.5 cm (5/8″ or approximately the diameter of a dime). Reported values represent the average of ten measurements per variety. Varieties that exceed the threshold are highlighted in red.

Contact your local Extension office and us if you have questions. 

Additional resources available:

Acknowledgments: 

Tyler Lynch, Senior Agriculturalist

Francisco H. Aispuro Arana, Graduate Research Assistant

Israel Molina Cyrineu, Graduate Research Assistant

Yanina Correndo, Graduate Research Assistant

Juan Bautista Bruno, Visiting scholar

Ana Sarah Silveira Barbosa, Visiting scholar

Oklahoma wheat planting – 2025

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Amanda de Oliveira Silva, Small Grains Extension Specialist

Soil moisture conditions are currently favorable for wheat planting across much of Oklahoma. Many of you may be eager to get seed in the ground, but before moving ahead, it is important to consider a few key points.

Planting date

For dual-purpose wheat (grazing + grain), the optimal planting window in most of Oklahoma is mid-September (Figure 1). Planting during this period provides the best balance between fall forage production and maintaining grain yield potential.

  • Early planting may increase fall forage production but also raises the risk of pests and diseases. It’s usually only recommended for wheat intended for graze-out or dual-purpose.
  • Grain-only wheat should generally be planted about 3-4 weeks later (mid-October, Figure 1) in many parts of the state. Our recent work shows there is more flexibility than we thought, and planting a little later can still work well depending on the weather.
Figure 1. Forage and grain yield potential in relation to the day of the year. Every 1,000 kg/ha is equal to approximately 900 lb/acre or 15 bu/acre. Ideal planting dates for dual-purpose wheat in Oklahoma are mid-September (i.e., approximately day 260). Planting for grain-only should occur at least 3-4 weeks after dual-purpose planting (i.e., mid-October or approximately day 285).

Watch for Fall Armyworms

Planting too early increases the chance of fall armyworm infestations. These pests are small and easy to miss, but you might notice “window-pane” feeding on leaves (Figure 2). Check beneath crop residue as well, since they often hide there during the heat of the day (Figure 3).

Figure 2. Symptom of “window paned” leaves shows severe feeding from the fall armyworm. Photo taken on October 2, 2019, at Canadian County by Amanda Silva.
Figure 3. Fall armyworms may be found under crop residue during the day. Photo taken on October 2, 2019 at Canadian County by Amanda Silva.

Volunteer wheat and Virus Risk

Early planting also raises the risk of wheat streak mosaic and Triticum mosaic viruses, spread by the wheat curl mite. Because seed treatments do not control these viruses and few varieties have strong resistance (i.e., Breakthrough), cultural practices are critical:

  • Control volunteer wheat and other grassy hosts as much as possible.
  • Ensure volunteer wheat is completely dead for at least two weeks before planting. This breaks the “green bridge” that mites use to move into new seedlings.
  • Planting a little later can also help lower virus pressure.

We saw significant wheat streak mosaic issues last year, making these steps especially important in 2025.

Other Planting Considerations

Before planting:

  • Soil test to guide fertility needs and reduce input costs.
  • Use high-quality seed to promote good germination and stand establishment.
  • Consider fungicide and insecticide seed treatments to protect against soilborne diseases and early pest pressure such as root rots.

Need More Information?

Your county OSU Extension office is a great resource for information. You can also reach out directly to us:

Pre-harvest sprouting and post-harvest seed dormancy in late harvested wheat

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Amanda de Oliveira Silva, Small Grains Extension Specialist, Oklahoma State University

The Oklahoma wheat harvest was delayed in many areas this year due to frequent rainfall events. I have received several questions about sprouted wheat seeds and potential issues with post-harvest dormancy, especially when using that grain for seed this fall. So, I would like to share a few considerations.

Pre-harvest sprouting

Pre-harvest sprouting refers to wheat grains that begin to germinate while still on the wheat head, before harvest. Once wheat reaches physiological maturity, it can begin to germinate if exposed to ideal moisture and warm temperatures for just a few days. That is what happened in some locations in northcentral OK this season.

The risk of sprouting depends on both genetics and environmental conditions. Wheat varieties differ in their resistance to sprouting (i.e., some are more prone to sprouting than others).

Can I use sprout-damaged wheat for seed?

It depends, especially on the level of sprouting.

  • If wheat kernels appear swollen or with a cracked seed coat, but with no visible root or shoot emerging from the seed, they might still be viable to be used as seed. In this case, run a germination test to assess seed quality before planting.
  • However, if you see visible roots or a developing coleoptile emerging from the seed (see Picture 1), those seeds should not be used. They will likely have poor viability and may fail to emerge.
Picture 1. Pre-harvest sprouted wheat damage, showing grain with split seed coat and radicle starting to become visible. The photo was taken on June 10, 2022 by Glen Calvert, former Extension Ag Educator at Washita County.

Will pre-harvest sprouting damage affect wheat quality?

Yes. As wheat starts to sprout (i.e., begins to germinate), it produces alpha-amylase and other enzymes that break down starch and protein in the grain. Increased enzyme activity can reduce flour and baking quality, affecting dough strength, loaf volume, and crumb structure. The more severe the sprouting, the greater the loss in marketability and end-use quality.

Post-harvest seed dormancy

Since harvest was late this year, will post-harvest dormancy affect planting this fall?

It is possible. Wheat seed is considered dormant when it fails to germinate even under favorable conditions or take so long that emergence is delayed, thus causing poor stands. Dormancy can be worsened when planting in warm soil (above 70F), which is typical during early sowing of graze-out or dual-purpose systems in Oklahoma.

Some level of seed dormancy is beneficial as it helps prevent pre-harvest sprouting as previously discussed. Dormancy is highest right before harvest and gradually decreases over time. But the rate at which it decreases depends on genetics and several other factors, including:

  • Seed coat properties: Inhibitory compounds in the seed coat of hard red winter wheat varieties can extend post-harvest dormancy.
  • Storage conditions: Seed stored at extreme temperatures (hot or cold) tend to lose dormancy faster than those stored at ambient air temperatures. This is why placing seed samples in a refrigerator for a day or two before conducting germination tests is a common practice.
  • Grain-fill environment: Cooler and wetter conditions during grain fill result in stronger dormancy than hot and dry conditions during this period. This means that the same wheat variety may exhibit different germination behavior depending on the environment in which the seed was produced.

For most hard red winter wheat varieties, dormancy naturally dissipates by October. However, early sowing shortens the interval between harvest and planting, which increases the risk of planting dormant seed, leading to delayed emergence and poor stands.

Dormancy can be mistaken by other problems like dead or damaged seeds. Running a germination test can help to identify what is going on.

What to check before planting saved seed:

  1. Germination Test

      Even if the grain didn’t visibly sprout in the head, it may have undergone internal changes (like enzyme activity) that reduce vigor. A standard germination test is the best way to assess viability.

      The Oklahoma Department of Agriculture, Food and Forestry offers this service. Click here for more information.

      2. Fungal infections and seed quality:

      Prolonged wet conditions during grain filling and harvest can lead to seed-borne fungal diseases. These can reduce seed quality and emergence. Consider using a fungicide seed treatment to reduce this risk.  

      3. Test weight and shrunken kernels

      Low test weight and shriveled seeds often indicate poor grain fill. These seeds might have reduced starch reserves, which weakens seedling growth.

      Aim for test weight above 58 lb/bu for seed use.

      Summary

      • Delayed harvest increases the risk of pre-harvest sprouting.
      • Both can impact seed viability and plant emergence this fall.
      • Before using your own grain as seed, be sure to run a germination test and assess overall seed quality.

      Resources:

      Oklahoma Wheat Harvest Moves Slightly Forward over Last Week – July 7, 2025

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      By: The Oklahoma Wheat Commission

      Oklahoma wheat harvest moved forward at a slow pace over the 4th of July weekend, with rain showers hitting several parts of the Panhandle, Northern and Northeast Oklahoma at different times. There is a region in the Goodwell, Guymon and Hooker area that is still working on irrigated wheat production that has been delayed due to rains this past week.  In North Central Oklahoma, little progress has been made, with producers cutting just to check moisture samples while fighting with mud. In Northeast Oklahoma progress was made over the weekend, but rain showers yesterday evening have put harvest at a standstill as of today.

      Several producers are weighing options as weeds become more of an issue. Test weights have dropped significantly in many parts of North Central Oklahoma in the 56 lbs. to 58 lbs. per bushel. Many producers have been surprised test weights have been holding up as good as they have been despite everything the crop has been through.

      The statewide average for test weight is still reported at  59 lbs. as much heavier weights were harvested earlier in the season. Yields across the state are ranging from the mid 40’s to mid 50’s for the most part, with some lower yielding wheat being reported due to heavy rains.

      Management intensive producers have reported higher yields ranging in the mid 60’s to mid 80’s. Producers had better wheat in many Northern parts of the state but now will see some yield loss due to lower test weights. Protein ranges have been all over the board from 9.8% to 14.2% depending on management and location. Protein average for the state of Oklahoma is at 11.2%. 

      The Oklahoma Wheat Commission is calling harvest 85% completed as of today. This will be the last harvest report of the season and will be considered a fair representation of quality in the state, even though some quality targets will be lower than expected on what remains.

      **It should be noted some minor instances of sprout has been reported at a 1% to 3% level, but in most regions the crop is still holding up without much sprout damage.  If sprout becomes more of an issue, then producers will most likely opt to utilize for feed wheat.

      Intensively managed wheat reported to be making in the mid 60’s. No protein was reported at this time. This region is considered to be 95% harvested.

      Garber/Kremlin/Hunter/PondCreek- Producers have been fighting mud in this region all harvest, with little movement over the past 5 days. Test weights have declined some ranging from 55 lbs. to 58 lbs. per bushel. Yields reported in the mid 40’s to mid 50’s for the most part. Some intensively managed fields making in the mid 60’s.  Protein averaging 11.2%. This region considered to be 57% harvested.

      Tonkawa/PoncaCity/Blackwell/Braman– Test weights being reported at 56 lbs. to         58 lbs. per bushel.  This region has had heavy rains the last 5 days putting harvest at a standstill for the past week. Yields on early cuttings ranging from low 40’s to mid 50’s for the most part. It should be noted that a large area in this region has suffered severe flooding and hail events.  Also several fields will most likely be abandoned due to heavy weed issues.  Protein on early cuttings averaging 11.1%.  This region is considered 52% harvested.

      Northeast Oklahoma

      Afton/Miami- Producers have fought rain in this region all harvest, but towards the beginning of the weekend a couple days was suitable for cutting, with producers making progress. Rain showers yesterday also halted further progress. This region reporting two classes — Hard Red Winter and Soft Red Winter wheat.  This region reported at 80% percent complete.

      **Hard Red Winter Class, test weights have been averaging 56 lbs. per bushel.  Yields are ranging in the mid 20’s to mid 50’s depending on variety and location.

      **Soft Red Winter Class, test weights have been averaging 56 lbs. per bushel. Yields are ranging in the mid 20’s to mid 50’s depending on variety and location. We did have a couple of yields reported in the low 70’s.

      Wheat Classes And What They Are Used For

      Hard Red Winter (HRW) – A versatile wheat with excellent milling and baking characteristics for pan bread. Hard Red Winter wheat is also a choice for Asian noodles, hard rolls, flat breads, general purpose flour and cereal.

      Soft Red Winter (SRW) – A versatile, weak-gluten wheat with excellent milling and baking characteristics suited for cookies, crackers, pretzels, pastries and flat breads.

      Panhandle

      Balko/Goodwell/Guymon/Hooker- A large portion of dryland harvest has now been completed in all regions of the Panhandle.   Dryland wheat harvest is 98 percent complete. A great deal of irrigated wheat harvest has taken place in central regions of the Panhandle around the Balko area, while producers in the Guymon and Hooker region have been delayed with rains and high humidity. Dryland wheat yields reported from 20 bushels to 50 bushels per acre depending on variety and location.   Irrigated wheat yields from 80 bushels to 120 bushels per acre.  Test weights on dryland wheat ranging from 55 lbs. to 62 lbs. per bushel depending on variety and location.   Test weight on irrigated wheat that was reported ranging from 57 lbs. to 61 lbs. per bushel.   Protein average for the Panhandle has varied more so than other years but many parts of the region looking at 12% averages.  The Panhandle region is considered 75 percent completed with harvest.

      Below, see the 7-day forecast provided by the Oklahoma Mesonet.

      NWS Days 1-5 Precipitation Forecast 

      The Days 1-5 Precipitation Forecast is produced by the National Weather Service’s Weather Prediction Center for July 7-12, 2025.  

      Oklahoma Wheat Harvest Makes Progress in Panhandle and Northeast Oklahoma, Stalled in Many Parts of North Central Regions

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      By: The Oklahoma Wheat Comission

      Oklahoma wheat harvest moves forward the last couple of days with harvesting still going on in Central and Northern parts of the state where rains have been missed. Large portions of North Central Oklahoma along the I-35 corridor have been plagued with rain this past week which has hindered any movement in that region.  Some producers in that area were going to try this afternoon, but many think it will be tomorrow or Friday at the earliest before they can get back in fields if it doesn’t rain again. The majority of harvest today and the last couple days has been taking place in the Panhandle and in Northeast Oklahoma, where they finally missed out on heavy rains. 

      The statewide average for test weight is still reported at  59 lbs. as much heavier weights were harvested earlier in the season. (Test weights are ranging now from 55 lbs. to 60 lbs. per bushel depending on variety, environment and location.) Yields across the state are ranging from the mid 40’s to mid 50’s for the most part, with some lower yielding wheat being reported due to heavy rains.

      Management intensive producers have reported higher yields ranging in the mid 60’s to mid 80’s. Producers had better wheat in many Northern parts of the state but now will see some yield loss due to lower test weights. Protein ranges have been all over the board from 9.8% to 14.2% depending on management and location. Protein average for the state of Oklahoma is at 11.2%.  The Oklahoma Wheat Commission is calling harvest 82% completed as of today.

      **It should be noted some minor instances of sprout has been reported at a 2 to 3% level, but in most regions the crop is still holding up without much sprout damage.

      North Central and Northern Oklahoma

      Okeene/Fairview/Ringwood/Lahoma- Test weights still coming in favorable ranging from 58 lbs. to 60 lbs. per bushel with many still 60 plus. Yields ranging from the mid 40’s to mid 50’s for the most part, with intensive management fields making 60 to 80 bushels. Protein reports are varying across this area with lower than expected proteins in some areas and much higher than expected proteins in other parts.   The protein average in this region is at 11.8%.  The Fairview/Ringwood/Lahoma areas are reported at 95% complete.

      McWillie/Helena/Goltry- Test weights still averaging 60 lbs. per bushel on later cuttings.  Yields ranging from high 30’s to mid 50’s depending on management practices. Some intensively managed wheat reported to be making in the mid 60’s. No protein was reported at this time. This region is considered to be 95% harvested.

      Kremlin/Hunter/PondCreek- Producers have been fighting mud in this region all harvest, with little movement over the past 5 days. Test weights have declined some ranging from 55 lbs. to 58 lbs. per bushel. Yields reported in the mid 40’s to mid 50’s for the most part. Some intensively managed fields making in the mid 60’s.  Protein averaging 11.2%. This region considered to be 55% harvested. Harvest has been at a standstill the last couple days, some producers were planning on trying to get into the field this afternoon if moisture dries down and no more rain comes.

      Tonkawa/PoncaCity/Blackwell/Braman– Test weights being reported at 56 lbs. to         58 lbs. per bushel.  This region has had heavy rains the last 5 days putting harvest at a standstill for the past week. Yields on early cuttings ranging from low 40’s to mid 50’s for the most part. It should be noted that a large area in this region has suffered severe flooding and hail events.  Also several fields will most likely be abandoned due to heavy weed issues.  Protein on early cuttings averaging 11.1%.  This region is considered 50% harvested. One producer was going to try to get back into the fields today, while others think it will be tomorrow or Friday at the earliest, if no more rain comes.

      Northeast Oklahoma

      Afton/Miami- Producers have fought rain in this region all harvest, but the last couple days they have not received heavy rains in this region like in other parts of Northern Oklahoma, which has allowed them to make great progress. This region reporting two classes — Hard Red Winter and Soft Red Winter wheat.  This region reported at 60% percent complete.

      **Hard Red Winter Class, test weights have been averaging 56 lbs. per bushel.  Yields are ranging in the mid 20’s to mid 50’s depending on variety and location.

      **Soft Red Winter Class, test weights have been averaging 56 lbs. per bushel. Yields are ranging in the mid 20’s to mid 50’s depending on variety and location.

      Wheat Classes And What They Are Used For

      Hard Red Winter (HRW) – A versatile wheat with excellent milling and baking characteristics for pan bread. Hard Red Winter wheat is also a choice for Asian noodles, hard rolls, flat breads, general purpose flour and cereal.

      Soft Red Winter (SRW) – A versatile, weak-gluten wheat with excellent milling and baking characteristics suited for cookies, crackers, pretzels, pastries and flat breads.

      Panhandle

      Balko/Goodwell/Guymon/Hooker- A large portion of dryland harvest has now been completed in all regions of the Panhandle.   Dryland wheat harvest is 90 percent complete. A great deal of irrigated wheat harvest has taken place in central regions of the Panhandle around the Balko area, while producers have started to get into irrigated wheat around the Guymon and Hooker areas the last couple days. Dryland wheat yields reported from 20 bushels to 50 bushels per acre depending on variety and location.   Irrigated wheat yields from 80 bushels to 120 bushels per acre.  Test weights on dryland wheat ranging from 55 lbs. to 62 lbs. per bushel depending on variety and location.   Test weight on irrigated wheat that was reported ranging from 58 lbs. to 61 lbs. per bushel.   No protein reported.  

      Below, see the 7-day forecast provided by the Oklahoma Mesonet.

      NWS Days 1-5 Precipitation Forecast 

      The Days 1-5 Precipitation Forecast is produced by the National Weather Service’s Weather Prediction Center for July 2-7, 2025.