Spring-planted oat for forage

Spring-planted oat has been a “go to” forage crop for southern Great Plains beef producers for years. It is a good option when winter wheat was not planted in the fall due to wet conditions, or, as is the case this year, when wheat failed to emerge due to drought. Forage production potential for spring-planted oat is around 1,500 to 2,00 lb/ac, but you will need about 60 – 75 lb/ac of nitrogen to make this type of yield. A fact sheet detailing spring oat production for hay can be found at www.wheat.okstate.edu.  I will provide the Cliff’s Notes version below.

Seed — Plant 80 – 100 lb/ac of good quality seed that has a germination of no less than 85%. There aren’t many options regarding varieties, so you will likely be limited to whatever seed is available in your area. The key is not to cut back on seeding rate, regardless of variety.

Seedbed — Sow oat seed at approximately 1/2 to 3/4 inches deep. Most producers will fare better with a conventionally-tilled seedbed. You are planting seed at a time of year when the ground is already marginal regarding temperature. Conventionally-tilled seedbeds warm more quickly, which should speed germination. There is one exception to the conventional till recommendation. If you are sowing into a stale seedbed or a failed wheat crop that is very thin, no-till should be okay. Just avoid situations where excessive residue will keep the soil cold.

Grazing — Oat plants should have a minimum of six inches of growth prior to grazing. Unlike fall-seeded cereals, you should not expect a large amount of tillering. Dr. Redfearn indicates a good stand of spring oat can provide a 750 lb animal approximately 60 days of grazing when stocked at 1.5 animals per acre

Hay — Oat should be cut for hay at early heading.

Plant growth regulators for wheat

Wheat lodging is not generally a widespread problem in Oklahoma, but it does occur. Lodging occurs due to a variety of factors, and as shown in the figure below, the timing of lodging will determine the final impact on grain yield. Lodging at head emergence, for example, can cause as little as 30 or as much as 80% yield reduction. The numbers in the figure do not account for harvest losses, which can exceed losses associated with lower photosynthetic capacity shown in the figure.

Slide05

Freeze injury or disease can cause lodging due to stem failure, which is characterized by plant stems breaking near the base. I the absence of weakened stems due to freeze or disease, most lodging in wheat is caused by failure of the root anchorage system (root lodging). Root lodging occurs when the anchorage system of a top-heavy wheat plant is weakened due to moist soil and wind provides sufficient force to overcome the rotational stiffness of the root/soil complex. Research has shown that increasing the soil water content from 17 to 26% reduced the force required for anchorage failure by 33%, and as little as 0.25 inches of water plus 11 mph winds were enough to cause lodging. The thicker the wheat crop and/or the taller the wheat crop, the more force that winds exert on the root anchorage system and the greater the likelihood of lodging.

Severe lodging in an Oklahoma wheat field in 2013

In 2013 and 2014 we evaluated the plant growth regulator trinexapac-ethyl, which is sold under the trade name Palisade®. Palisade is a giberellic acid inhibitor and works primarily by reducing plant height. In our study we evaluated 12 oz/ac of Palisade with and without 4 oz/ac of Tilt (propiconazole) applied at Feekes GS 7 (two nodes visible above the soil surface). We included an untreated check and ALL plots, including the check, received 10.5 oz/ac of Quilt Xcel at Feekes GS 10.5 (heading). We conducted the trial at Stillwater (Irr), Perkins (Irr), and Chickasha (Non-Irr).

 

I provided 2013 results in a blog post last year, and this post provides an update including our 2014 findings. While application of Palisade resulted in numeric reductions in plant height at Chickasha and Stillwater in 2013, differences among treatments were not statistically significant. In 2014 application of Palisade or Palisade plus Tilt significantly reduced plant height at Chickasha and Perkins.

Wheat plant height as affected by plant growth regulators in 2013

Wheat plant height as affected by plant growth regulators in 2013

 

Wheat plant height as affected by plant growth regulator in 2014

Wheat plant height as affected by plant growth regulator in 2014

We rated plots for lodging at harvest using a 1 – 10 scale with 0 equaling no lodging and 10 equaling complete lodging.  Application of Palisade plus Tilt reduced lodging over Palisade alone at Chickasha. Application of Palidsade or Palisade plus Tilt resulted in numeric reductions in lodging scores at Stillwater in 2013, but the result were too variable to result in statistical significance. Palisade did not affect lodging at Perkins in 2013. There was no lodging for any site or treatment in 2014.

 

Lodging as affected by plant growth regulator in 2013. No lodging occurred in 2014 regardless of treatment.

Lodging as affected by plant growth regulator in 2013. No lodging occurred in 2014 regardless of treatment.

 

Application of Palisade or Palisade plus Tilt increased grain yield at Chickasha and had no effect on grain yield at Stillwater or Perkins in 2013. It is interesting to note that the Palisade treatment increased grain yield at Perkins in 2013 even though the plots lodged at comparable levels as the non treated check. My best hypothesis is that the treated plots lodged later than the non treated plots, as all plots were standing at anthesis (see picture below). Application of Palisade or Palisade plus Tilt increased grain yield at Perkins in 2014 even though there was no lodging. There were no differences in grain yield at Stillwater or Chickasha in 2014. Lodging occurred at Chickasha, but occurred later in the season.

Wheat grain yield as affected by plant growth regulator in 2013

Wheat grain yield as affected by plant growth regulator in 2013

Wheat grain yield as affected by plant growth regulator in 2014

Wheat grain yield as affected by plant growth regulator in 2014

 

To summarize our work, we found a trend for one to two inch reductions in plant height when Palisade or Palisade plus Tilt were applied, but this did not consistently translate to increased grain yield. Our results are consistent with other wheat plant growth regulator research, which has reported similar variation in response among sites and years.  The literature also shows that reduction in lodging is relative to the straw strength of the variety. That is, a plant growth regulator will not make a lodging prone variety stand like one with excellent straw strength, rather they will make it less prone to lodging relative to the same variety non treated.

Based on current evidence, plant growth regulators in Oklahoma are best kept on acres with high (> 80 bu/ac) yield potential that may have greater propensity for lodging due to variety or fertility.  If these high yield potential acres are being sprayed with a growth regulator at GS 7, the addition of a foliar fungicide might be prudent if it can be included at a relatively low cost. This early-season fungicide application will not, however, substitute for a fungicide application at flag leaf.

Full disclosure: Syngenta donated the product for this trial, but the only funding for the research was provided by the Oklahoma Agricultural Experiment Station and the Oklahoma Cooperative Extension Service. We conducted a separate trial evaluating Palisade in drought stress environments that was partially funded by Syngenta. The analysis and recommendations made in this blog post are based on research findings from 2013 and 2014 production years. Recommendations may change as further research is conducted and new information is obtained.

First hollow stem update 02/19/15

First hollow stem is the optimal time to remove cattle from wheat pasture (full explanation). We measure first hollow in our September-sown wheat forage plots at Stillwater each year, and the warm temperatures have caused first hollow stem to advance ahead of schedule this year. The small grains extension crew split ten stems from each of the 56 lines tested in our program yesterday and Sy Llano, WB-Cedar, WB-Redhawk, and a few experimental lines were all at first hollow stem. Early varieties such as Gallagher, Greer, Everest, WB4458, TAM 114, and Brawl CL Plus are not far behind. A full listing of first hollow stem measurements are included in the table at the end of this blog. We will take another set of measurements the first of next week and report the results on this blog.

The numbers reported from Stillwater are likely behind those being observed in southern Oklahoma and ahead of those observed in northern Oklahoma. Jim Johnson with the Noble Foundation reported seeing quite a bit of first hollow stem in early varieties last week.

Probability of first hollow stem for early maturing wheat varieties as estimated on 02/19/15. Red areas indicate there is at least 50% likelihood that early-maturing wheat varieties have reached first hollow stem in the shaded area.

Probability of first hollow stem for early maturing wheat varieties as estimated on 02/19/15. Red areas indicate there is at least 50% likelihood that early-maturing wheat varieties have reached first hollow stem in the shaded area.

One week projection of first hollow stem for early-maturing wheat cultivars 02/19/15

One week projection of first hollow stem for early-maturing wheat cultivars 02/19/15

The First Hollow Stem Advisor on the Oklahoma Mesonet indicates that  early varieties in southern Oklahoma are likely past first hollow stem and that early varieties in central Oklahoma will reach this point within a week.

Keep in mind the one week projection uses historical weather conditions which are slightly above our current forecast. Cooler than normal conditions will not last long and wheat can grow anytime average daily temperature is above 32F. So, my advice is to move cattle off of wheat pasture in southern Oklahoma yesterday, start moving them off of wheat pasture in central Oklahoma today, and move cattle off wheat pasture in northern Oklahoma next week.

 

First hollow stem measured in wheat sown 09/16/2014 at Stillwater, OK. Varieties at or past first hollow stem (>1.5 cm of hollow stem) are shaded in red.
Variety cm of hollow stem 02/18/14
Endurance 0.1
Deliver 0.0
Pete 0.0
OK Rising 0.0
Billings 0.7
Ruby Lee 0.0
Garrison 0.1
Duster 0.1
Gallagher 1.2
Iba 0.2
Centerfield 0.0
Doublestop CL Plus 0.0
NF 101 0.9
Everest 1.3
1863 0.6
KanMark 0.5
Oakley CL 1.0
KS061406 0.4
Sy Llano 2.7
Sy Southwind 0.8
Greer 1.4
Jackpot 0.8
Sy Monument 0.0
06BC722#25 0.5
AP09T7631 0.7
WB-Cedar 1.5
WB-Redhawk 1.5
WB4458 1.3
WB-Grainfield 0.1
Winterhawk 0.8
T153 1.1
T154 0.6
T158 0.1
LCS Mint 0.7
LCS Wizard 0.4
LCS Pistol 0.8
LCH13DH-20-87 0.4
LCH13DH-14-91 1.8
TAM 112 0.9
TAM 204 1.0
TAM 113 0.7
TAM 114 1.3
CO11D174 0.5
Byrd 0.5
Brawl CL Plus 1.2
OK09125 0.9
OK1059060-2C14 0.4
OK10126 0.5
OK11D25056 0.2
OK11231 0.6
OK12621 0.7
OK13625 1.6
OK0986130-7C13 2.2
OK08P707W-19C13 0.9
OK10728W 1.0
OK11755W 1.2
Average 0.7

 

 

Checking for first hollow stem

First hollow stem occurs just prior to jointing and is the optimal time to remove cattle from wheat pasture. First hollow stem usually occurs in mid to late February in southern Oklahoma and early March in northern Oklahoma. Grazing past first hollow stem can reduce wheat grain yield by as much as 5% per day and the added cattle gains are not enough to offset the value of the reduced wheat yield.

Similar to previous years, we will monitor occurrence of first hollow stem in our wheat plots at Stillwater and report the findings on this blog. There is also a new first hollow stem advisor available on the Oklahoma Mesonet that can assist in determining when to start scouting.

Checking for first hollow stem is fairly easy.

  • You must check first hollow stem in a nongrazed area of the same variety and planting date. Variety can affect date of first hollow stem by as much as three weeks and planting date can affect it even more.
  • Dig or pull up a few plants and split the largest tiller longitudinally (lengthways) and measure the amount of hollow stem present below the developing grain head. You must dig plants because at this stage the developing grain head may still be below the soil surface.
  • If there is 1.5 cm of hollow stem present (see picture below), it is time to remove cattle. 1.5 cm is about the same as the diameter of a dime.
  • Detailed information on first hollow stem can be found at www.wheat.okstate.edu under ‘wheat management’ then ‘grazing’
  • Image
The plant on the left is past first hollow stem and is jointing. The plant on the right is at first hollow stem

The plant on the left is past first hollow stem and is jointing. The plant on the right is at first hollow stem

Wheat disease update – 11 February 2015

Wheat disease updates are written by Dr. Bob Hunger, OSU Extension Plant Pathologist

Oklahoma: Reports of diseases in Oklahoma have been sparse (as expected for this time of year) but certainly more numerous than last year when drought curtailed foliar diseases.  Yesterday (10-Feb) I found wheat leaf rust at a low, but consistent level in guard strips of Jagalene planted around a large wheat breeder nursery here in Stillwater.  Susceptible-type pustules were on lower leaves at 15-25%.  As temperature increases and with moisture this rust will increase and spread.

Gary Strickland (Extension Educator – southwest Oklahoma) indicated to me that he had heard reports of some leaf rust in Tillman County and also has seen a few pustules here and there on wheat in Jackson County, but nothing severe.  He has seen no powdery mildew and no root rots to speak of.  He also indicated there were a lot of acres of “little wheat” with some looking good if moisture had been received but that the southwest OK was quickly drying out.

Symptoms of wheat soilborne mosaic/wheat spindle streak mosaic (SB/SS) have shown up in Dr. Edward’s variety demonstration as well as in my SB/SS evaluation nursery, but symptoms are not yet striking as the flush of spring growth has not yet started.

Wheat soilborne mosaic virus can cause yellowing in the spring in susceptible varieties such as the one on the left.

Wheat soilborne mosaic virus can cause yellowing in the spring in susceptible varieties such as the one on the left.

 

Reports/excerpts of reports from other states:

Louisiana; Dr. Stephen Harrison (Professor; Wheat & Oat Breeder, LSU AGCenter) 3-Feb-2015:  “Stripe rust has been reported in several commercial fields and nurseries around central and northeast Louisiana.”

 

Texas Dr. Amir Ibrahim (Prof, Small Grains Breeding and Genetics, Texas A&M AgriLife Research) 3-Feb-2015:  “Wheat stripe rust found in Texas Blacklands area:  On January 29th, Russell Sutton, Assistant Research Scientist with the Small Grains program at Texas A&M University and our anchor in the northern Blacklands area and northeast Texas, visited our research plots near Ennis Texas. Russell found a small hot spot of stripe rust on the susceptible variety ‘Patton’ that we use as a spreader. The spot was about three feet in diameter and the lower leaves where heavily infected. The wheat appears to have completed the tillering stage and ready to begin jointing.  Russell will return in two weeks and collect some spores and look for more infection sites.

Time to start topdressing wheat

There are few crop inputs that deliver as much return on investment as nitrogen fertilizer. It takes approximately two pounds of nitrogen, costing approximately $1.00, to produce one bushel of grain worth about $5.00. Of course, nitrogen is not the only yield determining factor in a wheat crop. Also, the law of diminishing marginal returns eventually kicks in, but nitrogen fertilizer is still one of the safest bets in the house.

Top dress nitrogen fertilizer is especially important because it is applied and utilized at a time when the plant is transitioning from vegetative to reproductive growth. Several things, including the number of potential grain sites, are determined just prior to jointing and it is imperative that the plant has the fuel it needs to complete these tasks. Jointing also marks the beginning of rapid nitrogen uptake by the plant which is used to build new leaves, stem, and the developing grain head. The nitrogen stored in these plant parts will be used to fill the grain later in the season, and the plant is dependent on this stored nitrogen to complete grain fill.

In the bullet points below, I will hit the major points regarding top dress nitrogen for wheat.  I have also posted three slide presentations with audio regarding topdressing wheat at my YouTube channel available by clicking here or by searching YouTube for OSU Small Grains. 

When to apply

  • In order to have full benefit, nitrogen must be in the rooting zone by the time wheat is jointing. Jointing occurs around the end of February in southern OK and around the second week of March in northern OK.
  • Moisture is required to move nitrogen into the rooting zone. Since precipitation is usually very limited in January and February in Oklahoma we need the nitrogen out on the field when the precipitation arrives. This, along with the fact that we have 5.5 million acres to cover, means that we need to get started in January to get everything taken care of in a timely fashion.
  • If you are using the Sensor Based Nitrogen Recommendation system your yield predictions and nitrogen recommendations generally become more accurate as the season progresses; however, growers wishing to hedge their nitrogen bet could apply a partial top dress in January or early February and supplement with a second top dress just prior to jointing if SBNR recommendations call for additional nitrogen.
  • Do not apply nitrogen to frozen ground. Nitrogen will move with water. If melting snow or frozen rain is moving to the ditch, so will nitrogen applied to the soil surface.
  • Consider splitting or delaying top dress nitrogen applications to sandy soils until closer to jointing, as leaching can occur.

How much to apply

  • On average it takes about 2 lbs/ac of N for every bushel of wheat yield. In addition, dual-purpose wheat requires 30 lbs/ac of N for every 100 lbs/ac of beef removed. You can subtract your soil test NO3-N from these total requirements.
  • It is okay to adjust topdress N plans based on your current yield potential. When you submitted your soil test, you might have stated a 50 bu/ac yield goal which would require 100 lbs/ac of nitrogen; however, it is important to take a hard look and determine if this yield goal is still realistic based on your current crop status. I am not suggesting to adjust based on what you think the weather might do, but it is okay to take inventory and adjust your topdress N up or down based on current field conditions.
  • Don’t have an N-rich strip? It would be a lot cooler if you did. An N-rich strip would take the guess work out of adjusting your topdress N up or down based on your current crop conditions. Your county extension educator can provide more information on N-rich strips and you can find more information on the web at www.npk.okstate.edu

What source to use

  • The plant does not care about nitrogen source. A pound of nitrogen is a pound of nitrogen. Focus on getting the correct amount applied at the correct time, and choose your product based on price and application uniformity.
  • Use a source that can be applied uniformly. In my experience, spinner trucks or buggies are generally the least uniform. Air trucks or streamers are the most uniform.
  • Streamer nozzles almost eliminate leaf burn from UAN; however, leaf burn is generally not an issue until temperatures warm and/or you are applying fairly large amounts of UAN. Stream nozzles are also not affected much by wind and deliver a uniform pattern in a variety of conditions. There are also some studies that indicate banding of UAN through the use of stream nozzles will reduce nitrogen immobilization on crop residue. All in all, I am a big fan of streamer nozzles. You cannot, however, tank mix herbicides when using streamer nozzles.
    Streamer nozzles provide uniform application of UAN in a wide variety of environmental conditions.

    Streamer nozzles provide uniform application of UAN in a wide variety of environmental conditions.

    Poor nitrogen application can result in a streaked field. Some of the areas in this field were over fertilized while some were under fertilized resulting in wasted nitrogen and less than optimal crop yield.

    Poor nitrogen application can result in a streaked field. Some of the areas in this field were over fertilized while some were under fertilized resulting in wasted nitrogen and less than optimal crop yield.

Winter grain mites in northcentral OK

Jeff Bedwell forwarded reports of winter grain mites in Major and Alfalfa counties over the past week. This does not appear to be a widespread problem, but growers should check wheat fields to see if winter grain mites are present. We had a lot of issues with winter grain mites and brown wheat mites in Oklahoma last year. Unfortunately, many of these fields were not diagnosed until the damage was severe and visible from a distance. In this case, a rescue treatment was still effective at controlling the pest, but some yield loss had already occurred thus reducing the return on pesticide investment.

Winter grain mites are small (about 1 mm long) with black bodies and orange-red legs. Winter grain mites complete two generations per year and the adults can live for up to 40 days. The generation we are dealing with now resulted from oversummering eggs laid last spring. The second generation peaks in March/April and results from eggs laid in January/February.

Image

Winter grain mites on wheat near Blair, Oklahoma.

 

Scouting
Winter grain mites are not a problem you will notice in a timely fashion while standing up. You will need to get close to the soil surface and move residue to find these pests. Winter grain mites are light sensitive and prefer calm air to windy conditions; therefore, scouting early in the morning, late in the evening, or on cloudy days generally works best. Be sure to look under residue in no-till fields and under clumps of soil in conventional-till fields.

Scouting for winter grain mites requires getting close to the soil surface and moving residue to disturb mites.

Scouting for winter grain mites requires getting close to the soil surface and moving residue to disturb mites.

Injury

Winter grain mites feed by piercing plant cells in the leaf, which results in “stippling”.  As injury continues, the leaves take on a characteristic grayish or silverish cast.  Winter grain mites are more likely to cause injury in wheat if it is already stressed due to lack of moisture or nutrients. Also be advised that freeze injury can easily be confused for winter grain mite injury.

Wheat damaged by winter grain mite often has a silver or grayish appearance from a distance

Wheat damaged by winter grain mite often has a silver or bronzed appearance from a distance

When to spray
There are no established thresholds for winter grain mite. Healthy, well-fertilized wheat plants can generally outgrow injury, so it takes large numbers to justify control. If there is injury present AND large numbers of mites (~10 per plant) present in grain only wheat this time of year, you might consider control. If the wheat is to be grazed, I would simply monitor the situation in most cases and only spray if injury became severe.

What to spray
Malathion is the only product labeled for wheat in Oklahoma that has winter grain mite on the label. There are many additional products, such as some of the pyrethroids and chlorpyrifos, that are effective at controlling winter grain mite, but they don’t have a specific label for them. These products can be applied under 2ee regulations; however since this pest is not specifically labeled, the user assumes all responsibility for the application of the product.  It is also important to read and follow label directions regarding grazing restrictions for these and all pesticides.  Consult OSU Current Report 7194 Management of insect and mite pests in small grains for a more complete listing of available pesticides.

Wheat disease update – 31 October 2014

Wheat disease updates are written by Dr. Bob Hunger, OSU Extension Plant Pathologist

Oklahoma:  We’ve not seen any diseases so far this fall around Stillwater, but we have been relatively dry and much of the wheat was not planted until the past couple of weeks.  Mark Gregory (Area Extn Agron Spclt – southwestern OK) indicated to me earlier this week that he has not seen or heard any reports of leaf rust or other diseases.  However, Bryan Vincent (Crop Scout – NW/NC Oklahoma) sent me some photos of leaf rust pustules he found in several fields around the Aline-Helena area (30-40 miles northwest of Enid in north-central OK).  The pustules were extremely sparse and found only in very early planted wheat.  Bryan also reported seeing some light tan spot infections.  Leaf rust also has been observed in Kansas, Colorado, and Nebraska (see reports below), and stripe rust has been reported in Wyoming, Montana and the PNW.

Fall infestations of leaf rust rarely carryover to the spring and generally do not warrant treatment. Monitor fields and consider a split fungicide application in the spring if heavy foliar disease is still present at Feekes GS 6 - 7

Fall infestations of leaf rust generally do not warrant treatment. Monitor fields and consider a split fungicide application in the spring if heavy foliar disease is still present at Feekes GS 6 – 7 in early March

When leaf rust occurs in the fall in Oklahoma, the question arises regarding the value of spraying to control that rust.  Fall-infected leaf rust plants typically have yellowed lower/older leaves with rust pustules, but the youngest 2 or 3 leaves are green and healthy.  As temperature drops through November and December, the older rust-infected leaves die and new infections are greatly slowed and inhibited.  Grazing also helps to remove these leaves and increase air circulation and drying that are conditions less favorable to spread of the disease.  Given these considerations, spraying to control leaf rust in the fall is of limited value.  The primary concern with fall infections of leaf rust is that with a mild winter and sufficient moisture, the rust will survive through the winter and inoculum will be present in fields to start the disease early in the spring.  Hence, monitoring of these fields through the winter and early next spring is recommended to determine if a split application of a fungicide is merited to control the rust (and also possibly tan spot, septoria, and/or powdery mildew) in the early spring.

Reports/excerpts of reports from other states:

Kansas (Dr. Erick De Wolf, Extn Plant Pathologist, Kansas State University) 27-Oct-2014:  Wheat Leaf Rust Update in Kansas:  Planting of the winter wheat crop in Kansas is well underway. Farmers are reporting that wheat has emerged and is looking good in many areas of the state. Wheat planting on some farms was delayed by a late soybean harvest this fall, but these acres should be planted soon.

I was checking wheat this week in Manhattan (Northeast KS) and found leaf rust in some research plots.  This wheat was sown about 2-weeks prior to the optimal planting date but well within the normal planting range for wheat production in the state.  The leaf rust was not difficult to find with disease incidence near 5% some plots. The severity was 2 percent or less on most of the infected leaves. This level of fall infection of leaf rust is common in Kansas; however, 60% of the time cold temperatures and leaf desiccation during the winter months will eliminate the disease in many fields.

Ned Tisserat, retired plant pathologist from Colorado State University, also reported leaf rust in Northeast Colorado this past week. So it is possible that leaf rust is active in other areas of Kansas as well.  I will be checking other locations for leaf rust in Kansas this coming week and let the group now what I find.

Nebraska (Dr. Stephen Wegulo, Extn Plant Pathologist, Univ of Nebraska) 27-Oct-2014:  On Friday last week, Oct 24, I answered a call from a crop consultant who told me there is leaf rust in several wheat fields in the Panhandle of Nebraska.

Fall armyworm on the march!

by: Tom Royer, OSU Extension Entomologist

Fall armyworms are active this fall. I checked a field of wheat this past weekend with significant damage from fall armyworms that averaged 6-7 fall armyworms per square foot. Scout for fall armyworms by examining plants in several (5 or more) locations in the field. Fall armyworms are most active in the morning or late afternoon. Look for “window paned” leaves and count all sizes of larvae.

Fall armyworm damage is characterized by window panning on wheat leaves. Injury can sometimes be greater in field margins as armyworms sometimes move in from adjacent road ditches or weedy areas.

Fall armyworm damage is characterized by window panning on wheat leaves. Injury can sometimes be greater in field margins as armyworms sometimes move in from adjacent road ditches or weedy areas.

Fall armyworms are generally most active early in the morning or late in the evening. Spray when 2-3 armyworms per linear foot of row are present.

Fall armyworms are generally most active early in the morning or late in the evening. Spray when 2-3 armyworms per linear foot of row are present.

Examine plants along the field margin as well as in the interior, because they sometimes move in from road ditches and weedy areas. The caterpillars were widely distributed in the field that I checked, suggesting that they were the result of a large egg lay from a recent adult moth flight. The suggested treatment threshold is 2-3 larvae per linear foot of row in wheat with active feeding. We won’t get relief from fall armyworms until we get a killing frost, since they do not overwinter in Oklahoma.

Consult the newly updated OSU Fact Sheet CR-7194 Management of Insect and Mite Pests of Small Grains for control suggestions.

Wheat protein report – 2014

This blog post contains information from OSU Current Report 2135 Protein Content of Winter Wheat Varieties in Oklahoma. A complete pdf version of the report with a brief explanation of sampling procedures can be found at www.wheat.okstate.edu.

The grass always seems to be greener on the other side when it comes to wheat protein. In a low protein year, everyone is scrambling to find higher protein wheat to blend. In a high protein year, such as this one, the same low protein wheat that was considered marginally acceptable the year before might command a slight premium. While wheat protein is important to end users, wheat protein is just one of many attributes which determine end-use quality and marketability of winter wheat. In fact, some millers and bakers would argue that functionality of wheat protein is more important than the quantity of protein. While varietal differences commonly exist, differences in wheat protein among environments are generally much larger than differences among varieties. Factors such as nitrogen fertility and drought stress, for example, can sharply impact final protein content of the grain, and most producers are better served focusing on good agronomic practices than slight genetic differences in wheat protein content.

To reflect environmental impacts on wheat grain protein content, 2014 wheat variety test data are reported by variety and location in Table 1. The 18.5% average wheat grain protein for the Thomas location is a good example of how fertility and environment can impact protein content. Soil tests at the time of sowing revealed 141 lb/acre of residual nitrogen available, which should be enough to produce a 70 bu/acre wheat crop. Due to extreme drought, however, average grain yield at Thomas was 13 bu/acre. Under these circumstances, wheat plants were able to pull large amounts of nitrogen from the soil and move this nitrogen to the developing grain. Grain size was reduced and grains were shriveled due to drought, thus resulting in abnormally high wheat protein. A similar situation was reported for Altus in 2013.

In Table 2 we reported the wheat grain protein content as a deviation from location mean for each variety, as this provides easier comparison of wheat grain protein among varieties across locations. Billings, for example, is a variety with solidly positive deviation from location means, indicating it has a tendency for above-average grain protein content. Iba, on the other hand, has negative deviations from location means, indicating a tendency for lower than average grain protein content. Adequate nitrogen fertility as recommended by a recent soil test or sensor-based nitrogen management program can help ensure that varieties such as Iba produce grain protein within the acceptable range for end-use customers. Iba is also a prime example of how protein data can sometimes be misused, as the functionality of the protein in Iba is above average, which can offset lower absolute grain protein content.