About David Marburger

Since April 2016, I have served as the Small Grains Extension Specialist at Oklahoma State University. My research and extension efforts focus on delivering science-based recommendations in order to increase small grains production and profitability for stakeholders throughout Oklahoma and the southern Great Plains.

Follow-up to “What can I expect from wheat just now emerging?”

By: David Marburger, former OSU Small Grains Extension Specialist

 

Wheat that was dusted-in or late-planted during the fall 2017 and resulted in spotty stands or no stands at all from a lack of soil moisture was a frustrating and common occurrence for many Oklahoma producers. Unfortunately, the first water some wheat seed imbibed did not occur until after a late-February rainfall. When the remaining seed started germinating and emerging, many were begging the question, “What is a realistic expectation for this late-emerging wheat crop?” In a March 2018 blog article titled, What can I expect from wheat just now emerging? I tried addressing several related questions:

  • Will these plants produce a head?
  • How cold and for how long do the seedlings need to be exposed to cooler temperatures to vernalize?
  • Is vernalization completely temperature dependent?
  • Do we have information on varietal differences?
  • What forage or grain yield potential do I have?

 

I also mentioned in that article that we were working on gathering more variety-specific information. We had a small, unused space next to the variety demonstration plots at the Stillwater agronomy farm. In that small space we were able to plant more than 30 varieties that were entered in the OSU variety trials last season (Figure 1). These plots were established on March 6 and managed similarly to the “grain-only” demonstration plots located immediately to the north of this area. The “grain-only” demonstration plots were established on October 31, 2017 with a seeding rate of 60 lbs/acre. In-furrow DAP at 50 lbs/acre was also applied. Therefore, the intention was for the planting date to be the only difference.

figure 1

Figure 1. Planting wheat on March 6, 2018 at the Stillwater agronomy farm.

 

figure 2

Figure 2. Picture taken on April 26, 2018 of the wheat varieties planted 51 days earlier. The “dual-purpose” and “grain-only” variety demonstration trials are those located to the right of this area. Every wheat variety entered into the variety trials (n = 56) was planted on September 19, 2017 to represent a dual-purpose planting date (background) and on October 31, 2017 to represent a grain-only planting date (foreground).

 

figure 3 top

figure 3 bottom

Figure 3. Photos taken on May 16, 2018. The top photo shows the progress of the wheat varieties planted on March 6, 2018. The bottom photo shows the area where the same varieties were planted on October 31, 2017. You can see how some of the varieties in the bottom photo are beginning to “turn.”

 

figure 4

Figure 4. Photo taken on June 9, 2018. Some of the varieties planted on March 6, 2018 produced heads while others did not. The right side of the photo shows a few of the varieties from the dual-purpose demonstration trial that were a few days from being harvest-ready.

 

figure 5

Figure 5. Photo taken on June 21, 2018. This shows the differences in the number of heads produced or lack thereof among varieties planted on March 6, 2018. Varieties within both planting date demonstration trials to the right were harvest-ready for some time by this date.

 

What did we find?

In the previous blog article, I mentioned that variety-specific vernalization requirements are not fully characterized, but winter wheat varieties adapted to the southern Great Plains may need between 120 to 1080 hours (5 to 43 days) at air temperatures below 45° F to vernalize. Dr. Brett Carver feels three weeks (504 hours) of exposure to constant temperatures below 45° F should be sufficient for most varieties in Oklahoma, but reducing that to two weeks (336 hours) may cause vernalization issues for some varieties.

 

After this demo was established, we experienced a cool March and April overall. In fact, April 2018 ended up being the second coldest on record. Hourly weather data provided by Wes Lee from the Stillwater Mesonet station showed that we accumulated 368 hours after March 6 where the average air temperature was less than 45° F. The last calendar day which had at least one hour with an average temperature below 45° F was April 28.

 

As a result of these conditions, we found 28 of 35 varieties (80%) produced heads. The heading dates for those varieties are provided in Table 1. For the 28 varieties which produced heads, we collected samples from the plots planted on March 6, 2018 and October 31, 2017 in order to make comparisons for a few plant characteristics. Two subsamples were collected from each plot within both planting dates. Each subsample consisted of 1 m of row. Plant height, head number, total biomass, total grain weight, harvest index, and seed weight were measured from each subsample. The data for each plant characteristic was averaged from the two subsamples within each planting date, and the results are presented in Tables 1 and 2.

 

table 1

 

table 2

 

Results Summary

  • 28 of 35 varieties (80%) produced heads to some level. The varieties which did not produce heads were Doublestop CL Plus, Duster, Iba, Joe, Showdown, Stardust, and TAM 114.
  • Compared to the same varieties planted on October 31, 2017, the 28 varieties which produced heads and were planted on March 6, 2018 on average:
    • headed 40 days later (range of 28 to 50 days later);
    • were 36% shorter in plant height (range of -20% to -48%);
    • produced 49% less number of heads (range of -17% to -78%);
    • produced 76% less total biomass (range of -47% to -93%);
    • produced 80% less total grain weight (range of -49% to -98%);
    • had reduced seed weight per 50 seeds by 39% (range of -16% to -58%);
    • had reduced harvest index by 24% (range of +44% to -70%)

 

Other Observations

A couple producers also shared some of their findings from late-emerging fields. Fred Schmedt near Altus, OK mentioned that some of their Bentley and Smith’s Gold which was planted into cotton stubble and emerged in the first week of March did produce grain. The yields they had were pretty similar to those for the same varieties in our demonstration. Jimmy Kinder near Walters, OK also had some Bentley which produced grain, and his yield was slightly better than yield for Bentley in our demonstration.

 

As a comparison to Stillwater, Wes Lee also provided me the hourly weather data from the Altus and Walters Mesonet stations. The number of accumulated hours beginning after March 6 where the average air temperature for the hour was below 45° F was 277 for Altus and 245 for Walters. The true number of accumulated hours though depended on the time when the seed of these varieties in these fields imbibed water and sprouted.

 

 

Final Thoughts

Hopefully Oklahoma winter wheat producers will never run into this problem again, and we can just put these data on the shelf to collect dust. If it does happen again though, these observations can at least give us a starting point to help aid in making more confident and timely decisions on how to move forward. However, it does not look good for forage or grain yield potential any way you slice it (as likely expected), and contacting your agent if you have crop insurance to discuss your options is highly advised. Also keep in mind that these results are from one location in one year under the cultural practices used. Seeding rate is an example of how cultural practices may influence the results. Using a higher seeding rate in attempt to compensate for less tiller production in a late-planted wheat scenario may not reduce total biomass and grain yield as dramatically compared to the observations in our demonstration.

 

Planting Date and Seeding Rate Considerations for Winter Wheat

With this August setting up similar to last year and the need for wheat pasture for a number of producers this fall, we will likely see drills start rolling in parts of the state by the end of the month. As planting gets going, here are a couple considerations when it comes to planting dates and seeding rates for Oklahoma winter wheat.

 

Planting date:

The optimal window for dual-purpose wheat for most of Oklahoma is between September 10-20 (approximately day 260 in Figure 1). This window represents a trade-off between maximizing forage production while minimizing potential grain yield loss. Earlier planting dates, last week into this week for example, will provide more fall forage potential, but this is usually not recommended unless the wheat is intended to be produced for grazing, or “grazeout.” Planting dates for grain-only producers will be at least 2-3 weeks later than what is the ideal dual-purpose planting date for your area. For many areas in Oklahoma, this will be around mid-October (approximately day 285 in Figure 1).

Fig1 planting date

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 2-3 weeks after dual-purpose planting (i.e., mid-October or approximately day 285).

 

Seeding rate:

Producers in forage-only or dual-purpose management should plant 1.5-2x the amount of seed that is recommended for grain-only production. For example, data collected in north-central Oklahoma has showed that increasing the seeding rate from 60 to 120 lb/acre can increase fall forage potential by as much as 500 lb/acre for a mid-September planting date (September 11 in Figure 2). The increase in forage potential by using this higher seeding rate can justify the cost of the extra seed. OSU recommends 120 lb seed/acre for most areas of Oklahoma, including irrigated fields in the Panhandle. Seeding rates for dryland fields in the Panhandle for this type of management can be lowered to 90 lb/acre. OSU recommends a 60 lb/acre seeding rate for grain-only production when planted during that optimal mid-October time. Dryland fields in the Panhandle can have their seeding rate lowered to 45 lb/acre. If planting happens to get delayed in November this year, seeding rates will need to increase to provide enough available tillers to still maintain maximum grain yield potential.

Fig2 seeding rate

Figure 2. Fall forage yield collected in north-central Oklahoma as affected by seeding rate and planting date. Source: PSS-2178.

 

More information about dual-purpose wheat management can be found in the fact sheet PSS-2178 Dual-purpose Wheat: Management for Forage and Grain Production.

Disease and Insect Considerations to Make Before Planting Wheat This Fall

This article was written by Dr. Bob Hunger, Extension Wheat Pathologist, & Dr. Tom Royer, Extension Entomologist, Department of Entomology & Plant Pathology Oklahoma State University

 

Planting date: Much of the winter wheat in Oklahoma is sown with the intent of being used as a dual-purpose crop. In such a system, wheat is grazed by cattle from late fall through late winter/early spring and then harvested for grain in early summer. In a grain-only system, wheat is generally planted in October, but in a dual-purpose system wheat is planted in early to mid-September to maximize forage production. Planting wheat early significantly increases the likelihood that diseases and insect pests such as mite-transmitted viruses, the aphid/barley yellow dwarf complex, root and foot rots, and Hessian fly will be more prevalent and severe. For more detailed information on planting date and seed treatment considerations on wheat, see CR-7088 Effect of Planting Date and Seed Treatment on Diseases and Insect Pests of Wheat at http://wheat.okstate.edu/wheat-management/seeding/CR-7088web2012.pdf.

 

Mite-transmitted virus diseases: These virus diseases are transmitted by wheat curl mites (WCMs) (Figure 1), and include wheat streak mosaic (WSM), high plains disease (also called wheat mosaic), and Triticum mosaic (TrM). WCMs and these viruses survive in crops such as wheat, corn, and sorghum as well as many grassy weeds and volunteer wheat. In the fall, WCMs spread to emerging seedling wheat, feed on that seedling wheat, and transmit virus to the young wheat plants.

 

Given this disease cycle, it is easy to see several factors that determine the incidence and severity of these diseases. First, controlling volunteer wheat and other grassy weeds that serve as alternative hosts for the mite and the viruses is imperative to help limit these diseases. Often an infected field of commercial wheat is growing immediately adjacent to a field left fallow during the fall and winter (Figure 2). The fallow field contained abundant volunteer wheat and grassy weeds from which WCMs carrying Wheat streak mosaic virus (WSMV) spread into the commercial field. Wheat infected in the fall will be severely damaged the next spring. Wheat infected in the spring also is damaged, but not as severely as wheat infected in the fall. Hence, it is imperative to do yourself and your neighbors a favor by controlling volunteer wheat and grassy weeds in fields left fallow – especially, if they are adjacent to commercial wheat fields.

 

A second factor linked to the severity of these mite-transmitted virus diseases is planting date. Early planting dates associated with grazing provides for a much longer time period in the fall for mites to spread to and infect seedling wheat. Planting later in the fall (after October 1 in northern OK and after October 15 in southern OK) and controlling volunteer wheat are the two practices that can be employed to help manage these diseases. It is extremely critical that volunteer wheat is completely dead for at least two weeks prior to emergence of seedling wheat because WCMs have a life span of 7-10 days. Thus, completely killing or destroying volunteer wheat for a period of at least two weeks prior to emergence of seedling wheat will greatly reduce mite numbers in the fall.

 

The incidence and severity of these mite-transmitted virus diseases as affected by planting date can be illustrated by the number of samples that tested positive for WSMV and HPV in 2017 compared to 2018.  In 2017, 103 wheat samples were tested by the Plant Disease and Insect Diagnostic Lab at OSU for presence of mite-transmitted viruses. Of these 103 samples, 69 (67%) tested positive for WSMV and 22 (21%) tested positive for HPV. In 2018, only 12 of 126 (10%) samples were positive for one or both of these viruses. For a number of reasons, the planting date of wheat across Oklahoma in the fall of 2017 was significantly later than the fall of 2016. I believe this helped to lower incidence and severity of the mite-transmitted viruses in Oklahoma in 2018 compared to 2017.

 

Finally, seed treatments and insecticides are not effective in controlling the mites or these mite-transmitted virus diseases. Regarding resistant varieties, there are several winter wheat varieties that have resistance to either WSM or the curl mites, but the adaptation of these varieties to Oklahoma is limited, and the resistance is not typically an absolute resistance to the disease. Hence, severe and continuous disease pressure especially at higher temperature (greater than about 75 F) can overcome the resistance.  For more information on mite-transmitted virus diseases, see OSU Fact Sheet 7328 Wheat Streak Mosaic, High Plains Disease and Triticum Mosaic: Three Virus Diseases of Wheat in Oklahoma) at: http://wheat.okstate.edu/wheat-management/diseasesinsects/EPP-7328%20three%20virus%20diseases%20of%20wheat.pdf.

Figure1

Figure2

Aphid/barley yellow dwarf (BYD) complex: Viruses that cause BYD are transmitted by many cereal-feeding aphids (Figure 3). BYD infections that occur in the fall are the most severe because virus has a longer time to damage plants as compared to infections that occur in the spring. Several steps can be taken to help manage BYD. First, a later planting date (after October 1 in northern Oklahoma and after October 15 in southern Oklahoma) helps reduce the opportunity for fall infection. Second, some wheat varieties (e.g., Duster, Billings, Gallagher, Iba, Bentley, Tatanka, and Winterhawk) tolerate BYD better than other varieties; however, be aware that no wheat variety has a high level of resistance to the aphid/BYD complex. Third, control aphids that transmit the viruses that cause BYD. This can be done by applying contact insecticides to kill aphids, or by treating seed before planting with a systemic insecticide. Unfortunately, by the time contact insecticides are applied, aphids frequently have already transmitted the viruses that cause BYD. Systemic seed-treatment insecticides containing imidacloprid or thiamethoxam can control aphids during the fall after planting. This may be particularly beneficial if wheat is planted early to obtain forage. Be sure to thoroughly read the label before applying any chemical.

Figure3

Hessian fly: Hessian fly (Figure 4) infestations can occur in the fall and spring. Fall infestations arise from over-summering pupae that emerge when climate conditions become favorable. In states north of Oklahoma, a “Hessian fly free” planting date often is used to help limit fall infestations by Hessian fly. However, such a planting date does not apply in Oklahoma because Hessian fly can emerge in Oklahoma as late as December (Figure 5).

Figure4

Figure5

Delayed planting (after October 1 in northern Oklahoma, and after October 15 in southern Oklahoma) can help reduce the threat of Hessian fly, but a specific “fly free date” does not exist for most of Oklahoma as it does in Kansas and more northern wheat-growing states. This is because smaller, supplementary broods of adult flies emerge throughout the fall and winter. Some wheat varieties are either resistant (e.g., Duster, Gallagher, SY Flint, and LCS Wizard) or partially resistant [e.g., LCS Chrome, Everest, Ruby Lee (at cooler temperatures)] to Hessian fly infestations. Hessian fly infestations can be reduced somewhat by destroying volunteer wheat in and around the field at least two weeks prior to emergence of seedling wheat. Seed treatments that contain imidacloprid or thiamethoxam will also help reduce fly fall infestations, especially if combined with delayed planting and volunteer destruction. For more information on Hessian fly, see OSU Fact Sheet EPP-7086 Hessian fly Management in Oklahoma Winter Wheat at: http://wheat.okstate.edu/wheat-management/diseasesinsects/EPP7086hessianflyinoklahoma.pdf.

 

Root and foot rots: These are caused by fungi and include several diseases such as dryland (Fusarium) root rot, Rhizoctonia root rot (sharp eyespot), common root rot, take-all, and eyespot (strawbreaker) (Figure 6). During the late spring of 2016 and 2017, several samples of wheat were received that were diagnosed as being affected by take all and other root rots. In 2017-2018, the incidence and severity of root rots across Oklahoma dramatically increased. This increase likely resulted from weather conditions that favored the root rots. Dryland (Fusarium) root rot was the most common root rot observed, and caused significant damage to wheat in southwestern, western, northwestern OK as well as the panhandle.

 

Controlling root and foot rots is difficult. There are no resistant varieties, and although fungicide seed treatments with activity toward the root and foot rots are available, their activity usually involves early-season control or suppression rather than control at a consistently high level throughout the season. Often, there also are different “levels” of activity related to different treatment rates, so again, CAREFULLY read the label of any seed treatment to be sure activity against the diseases and/or insects of concern are indicated, and be certain that the seed treatment(s) is being used at the rate indicated on the label for activity against those diseases and/or insects. Later planting (after October 1 in northern Oklahoma and after October 15 in southern Oklahoma) also can help reduce the incidence and severity of root rots, but planting later will not entirely eliminate the presence or effects of root rots. If you have a field with a history of severe root rot, consider planting that field as late as possible or plan to use it in a “graze-out” fashion if that is consistent with your overall plan. For some root rots, there are specific factors that contribute to disease incidence and severity. For example, a high soil pH (>6.5) greatly favors disease development of the root rot called take-all. OSU soil test recommendations factor in this phenomenon by reducing lime recommendations when continuous wheat is the intended crop. Another practice that can help limit take-all and some of the other root rots is the elimination of residue. However, elimination of residue by tillage or burning does not seem to affect the incidence or severity of eyespot (strawbreaker).

Figure6

Seed treatments: There are several excellent reasons to plant seed wheat treated with an insecticide/fungicide seed treatment. These include:

  1. Control of bunts and smuts, including common bunt (also called stinking smut) and loose smut. The similarity of these names can be confusing. All affect the grain of wheat, but whereas common bunt and flag smut spores carryover on seed or in the soil, loose smut carries over in the seed. Seed treatments are highly effective in controlling all the bunts/smuts. If common bunt (stinking smut) was observed in a field and that field is to be planted again with wheat, then planting certified wheat seed treated with a fungicide effective against common bunt is strongly recommended. If either common bunt or loose smut was observed in a field, grain harvested from that field should not be used as seed the next year. However, if grain harvested from such a field must be used as seed wheat, treatment of that seed at a high rate of a systemic or a systemic + contact seed treatment effective against common bunt and loose smut is strongly recommended. For more information on common bunt & loose smut, see: http://www.entoplp.okstate.edu/ddd/hosts/wheat.htm and consult the “2017 OSU Extension Agents’ Handbook of Insect, Plant Disease, and Weed Control (OCES publication E-832),” and/or contact your County Extension Educator.
  2. Enhance seedling emergence, stand establishment and forage production by suppressing root, crown and foot rots. This was discussed above under “Root and Foot Rots.”
  3. Early season control of the aphid/BYDV complex. This can be achieved by using a seed treatment containing an insecticide. Be sure that the treatment includes an insecticide labeled for control of aphids.
  4. Control fall foliar diseases including leaf rust and powdery mildew. Seed treatments are effective in controlling foliar diseases (especially leaf rust and powdery mildew) in the fall, which may reduce the inoculum level of these diseases in the spring. However, this control should be viewed as an added benefit and not necessarily as a sole reason to use a seed treatment.
  5. Suppression of early emerged Hessian fly. Research suggests that some suppression can be achieved, but an insecticide seed treatment has little residual activity past the seedling stage.

 

2017-2018 Oklahoma Wheat Crop Overview

At the time of writing this report, 2018 Oklahoma wheat production is estimated to be 52.0 million bushels, which is 47% less than the 2017 production (Table 1) and 62% less than the 2016 production. The lower total grain production is the result of less wheat acres harvested across the state, primarily from abandonment due to drought or baled for hay, and the below-average yield. The 4.3 million planted acres was only down 4% compared to the previous year, but that was still 18% lower than the previous ten-year average. Number of harvested acres is estimated at 2.0 million, which is 31% less than in 2017 (Table 1), and the lowest number in the state since 1913. The statewide average yield is projected at 26 bu/ac. This is 8 bu/ac (24%) less than the 2017 state average and 3.6 bu/ac (12%) less than the previous ten-year average.

table 1

The 2017-2018 wheat growing season was a fight from start to finish for many producers across the state. The growing season got an early start due to an unusual August for Oklahoma. Temperatures were below normal, and rainfall totals were above normal for the month. This prompted producers interested in targeting fall forage to begin planting at the end of August. Planting continued to move rapidly through the Labor Day weekend, and most of the wheat during this time was sown into adequate soil moisture and emerged rapidly. Those producers who waited until after Labor Day to plant saw more unfavorable conditions as temperatures rose, and available soil moisture quickly dried up. Wheat planted during this time was “dusted-in” and finally received precipitation toward the end of the month into the beginning of October to get the seed to germinate. Wheat planting intended for grain-only was stalled during the average timeframe of early to mid-October due to these precipitation events. Once the ground dried enough, most producers were able to quickly make up time and get the crop planted, but some needed until November to finish.

 

After mid-October, the rain quit falling for the remainder of the calendar year. Crop conditions during the early part of the season were average but quickly deteriorated as the season progressed. This also led to a disappointing fall forage production and grazing season for most producers. Those who planted during late August to early September and were able to protect the crop from fall armyworm achieved good stands and had some available pasture later in the fall. However, those who waited until after Labor Day or later to plant were not as fortunate. The later planting and lack of precipitation resulted in low total fall forage production or no available pasture at all.

 

Drought conditions and average to below average temperatures persisted throughout January into February. Even for the producers who had available fall pasture, the drought conditions limited the overall number of days of grazing.

 

Some precipitation finally fell in parts of the state during late February into early March. For many fields, this was the first precipitation received since planting. Below average temperatures were observed coming out of winter, and plants broke winter dormancy later than normal. Below average temperatures persisted, resulting in slow overall growth and development during this time. The first hollow stem growth stage was reached for many varieties during the second to third week of March, which was 7 to 10 days later than normal. Unfortunately, the rain received during late February to early March was not quite enough to give any grazed wheat the boost it needed to recover well.

 

Overall growth and development continued at a slower than normal pace due to the second coldest April on record. Three separate and widespread freeze events also occurred during the first week of April, resulting in significant injury in some areas. Most wheat headed during mid- to late April because of the cooler temperatures, with this being 7 to 14 days behind normal. The prevailing thought was that this would translate into a later than normal harvest. However, the cold temperatures in April were followed by the warmest May on record. The warm temperatures and lack of rainfall advanced the crop quickly at this point, resulting in suboptimal conditions for the grain-fill period.

 

Most wheat was mature in southwestern Oklahoma by the end of May and by the beginning of June in the central to northern parts of the state. Producers for the most part were not delayed by rainfall events, and with the dry weather during June, much of the wheat was harvested timely and quickly.

 

Overall, harvest was almost complete in the state by late June. Yields throughout Oklahoma were variable depending on location but were below average overall. Part of this variability was due to overgrazing and whether an area caught or missed a rainfall event during early spring. Field averages of 15 to 30 bu/ac were the norm across much of the state, but higher averages, even into the 50 to 60 bu/ac range, were not uncommon in some areas that received timely rainfall. Test weights throughout harvest remained at or above 60 lb/bu for early-harvested fields and did not drop much below the upper 50’s towards the end of harvest. Protein content also remained at or above acceptable levels.

 

Different insects were a concern at times during the growing season, but few were widespread or season-long outside of the fall armyworm. Unless treated, the fall armyworm devastated those producers who planted in late August into early September. Many fields had to be replanted, and some producers commented that this was the worst that they had ever observed. Unfortunately, some reports indicated the fall armyworm was still causing damage into early November. The dry weather experienced across the state through the winter provided ideal conditions for winter grain mite and brown wheat mite to thrive on wheat plants coming out of winter dormancy, and there were some reports of fields warranting control. Aphids were not really on the radar screen of most producers until mid-March, but this pest was still not the limiting factor as observed in other years. Despite the low aphid numbers, Barley Yellow Dwarf (BYD) was evident in some fields as flag leaves and heads started to emerge. While there was quite a bit of leaf purpling and yellowing associated with BYD, there was not much stunting observed, with stunting resulting from “hot spots” of aphid pressure with early-season transmission of the virus. Wheat Streak Mosaic (WSM), transmitted by the wheat curl mite, was an issue again for producers in southwestern Oklahoma, but the overall impact of WSM was not as much as the 2016-2017 crop season. Reasons for this were related to later planting and emergence of some wheat; additionally, fields which may have had WSM were abandoned due to the drought or cut and baled for hay before symptoms could be observed.

 

Diseases were at low levels overall during the season, primarily due to the drought conditions. Parts of central to southcentral Oklahoma did experience low levels of powdery mildew, leaf rust, and stripe rust. In some cases, powdery mildew could be observed high in the canopy. For the remainder of the state, it was difficult to find foliar diseases, especially during stem elongation into the grain-fill period. One disease more prominent than in years past was Fusarium foot dry (dryland root rot). Signs and symptoms of this disease appeared suddenly during early May as hot temperatures returned and as the crop progressed through grain-fill. However, symptoms of this disease can appear similar to symptoms of premature death caused by freeze, drought, and other conditions. In parts of the northwest and panhandle regions, symptoms of dryland root rot may have been confused with symptoms caused by the drought and/or freeze, whereas in others (such as the wheat variety trial at Lahoma), damage caused by the April freeze events was expressed distinctly earlier. Because of the impact that leaf rust and stripe rust have had over the past several years, producers were ready to apply a foliar fungicide to susceptible varieties, but unfavorable conditions for disease development did not warrant an application in most cases. Variety trial results from Apache and Lahoma indicated that producers in these areas were justified in not spraying, as no evidence of a positive response to a fungicide application was found. However at Chickasha where low to medium levels of leaf and stripe rust and medium to high levels of powdery mildew were present, the two fungicide applications implemented at this location contributed to protecting the yield potential for a number of varieties compared to the non-treated plots of those same varieties.

Harvest for Oklahoma Wheat About to Wrap Up

Report by the Oklahoma Wheat Commission

 

Despite the scattered rains across parts of Northern Oklahoma this week, harvest progressed in most areas. Rainfall in the Panhandle region was limited and this allowed harvesters to get a majority of the irrigated wheat out of the fields. It is reported across the Panhandle and in North Central Oklahoma that approximately 5% of the crop is left in the field to harvest. In Northern Oklahoma the issue now is muddy fields, but producers are hopeful they will get back in these areas by the end of the weekend to finish this 2018 season. Test weights declined in Northern Oklahoma this past couple weeks with all the moisture. Most elevators are reporting that since the majority of the crop was harvested before the rains, overall it is not going to impact the final averages. Grain quality for the 2018 wheat crop across Oklahoma will be favorable with high test weights and high protein contents. Test weights on average will range from 60 to 62 lbs./bu., with reports on protein running 12.5 to 13%.  While quality will be high, the amount USDA currently estimates the Oklahoma Wheat crop to be forecasted at is 52 million bushels, down 47 percent from last year. Yield per acre is expected at 26 bushels, with 2 million acres that will be harvested.  This will be the last harvest report published by the Oklahoma Wheat Commission for the 2018 season.

 

Percentages of Harvest Completed Across Oklahoma

Southwest Oklahoma 99% Complete

South Central Oklahoma 99% Complete

Central Oklahoma 99% Complete

West Central Oklahoma 99% Complete

North Central Oklahoma 95% Complete

Northwest Oklahoma 98% Complete

Northeast Oklahoma 99% Complete

Panhandle 95% Complete

Entire State of Oklahoma 98% Complete

 

For more information on winter wheat acreage, yield and production estimates in other states click on the USDA June Crop Production Report listed below.

https://www.nass.usda.gov/Statistics_by_State/Oklahoma/Publications/Oklahoma_Crop_Reports/2018/spr-crop-prod-06-2018.pdf

Harvest for Oklahoma Wheat Slows this Week with 93% of Harvest Completed

Report by the Oklahoma Wheat Commission

 

The Oklahoma wheat harvest has not progressed much from our report given on Tuesday, June, 19th due to the rains that have been going through the Panhandle and Northern regions of Oklahoma over this past week. Some producers have reported over 6 inches of moisture in the last seven days, even in several parts of the Panhandle. As of today, harvest has been progressing in Boise City, where moisture received has still been slim. Producers in other parts of the Panhandle are hoping to get into the fields today and tomorrow. While in some areas, it will still be a few more days, even in parts of Northern Oklahoma. Grain quality to this point continues to be favorable with high test weights and high proteins; however, the producers in parts of Northern Oklahoma are concerned that test weights will be impacted on what is left in the field. Nothing has been reported on irrigated wheat in the Panhandle regions since many producers were just getting started with harvest before the rains came in. Test weights are averaging 60 to 62 lbs./bu. on the wheat being harvested today in the Panhandle, with reports on protein running 12.5 to 13%. Yields reported on the dryland have ranged from 10 bushels per acre to the mid 20’s. An occasional report of dryland wheat making in the high 30’s has been reported.

 

Percentages of Harvest Completed Across Oklahoma

Southwest Oklahoma 99% Complete

South Central Oklahoma 99% Complete

Central Oklahoma 99% Complete

West Central Oklahoma 99% Complete

North Central Oklahoma 85% Complete

Northwest Oklahoma 94% Complete

Northeast Oklahoma 99% Complete

Panhandle 52% Complete

Entire State of Oklahoma 93% Complete

 

For more information on winter wheat acreage, yield and production estimates in other states click on the USDA June Crop Production Report listed below.

https://www.nass.usda.gov/Statistics_by_State/Oklahoma/Publications/Oklahoma_Crop_Reports/2018/spr-crop-prod-06-2018.pdf

 

The next harvest report from the Oklahoma Wheat Commission will be published on Tuesday July 3, 2018. 

Harvest for Oklahoma Wheat 90% Complete

Report by the Oklahoma Wheat Commission

 

The Oklahoma Wheat harvest is mostly complete for the Southwest, South Central, Central, West Central, Central, and Northeast parts of the state. In some of these areas, producers are finishing up with their last fields. Harvest continues to move forward in the North Central, Northwest, and Panhandle regions of the state. Across the state, test weights continue to be favorable, with above average proteins reported from the Oklahoma/Texas line to the Oklahoma/Kansas line. Based on reports from elevator managers, this week’s harvest continues to come in with lower than predicted yields from the North Central part of the state. Dryland wheat yields in the Panhandle region being harvested are coming in with higher yields than predicted, but many of those yields are still making in the low 20’s with an occasional dryland yield being reported in the mid 30’s depending on the location. Some of the irrigated wheat around Guymon has been harvested, but no reports on yields have been received. While yields across the state have not been as favorable as the industry would like, overall quality of this crop still looks to be encouraging as producers in the Northern and Panhandle regions of the state work to get the crop out. The USDA June 12th Crop production estimates for Oklahoma are predicting 2 million acres to be harvested with a 26 bushel per acre yield, making the Oklahoma production estimate 52 million bushels for the 2018 crop.

 

Percentages of Harvest Completed Across Oklahoma

Southwest Oklahoma 99% Complete

South Central Oklahoma 99% Complete

Central Oklahoma 99% Complete

West Central Oklahoma 99% Complete

North Central Oklahoma 77% Complete

Northwest Oklahoma 90% Complete

Northeast Oklahoma 99% Complete

Panhandle 50% Complete

Entire State of Oklahoma 90% Complete

 

For more information on winter wheat acreage, yield and production estimates in other states click on the USDA June Crop Production Report listed below.

https://www.nass.usda.gov/Statistics_by_State/Oklahoma/Publications/Oklahoma_Crop_Reports/2018/spr-crop-prod-06-2018.pdf

 

North Central Oklahoma

 

Enid- Harvest is reported to be 95% complete. Test weights are ranging all over the board, from 56 to 62 lbs./bu. depending on the variety and location. The average test weights for this area to date are 59 to 60 lbs./bu. Proteins are reported to be ranging from 11.5 to as high as 16%. Elevator locations for the most part have been saying that as harvest progresses overall, they will be looking at a 12.5% protein average for the region. Yields have been reported all over the board from the mid teens to the mid 30’s.

Kremlin/Medford/Nardin/Nash/Renfrow- Harvest is 75 to 80% complete depending on the location. Test weights have been averaging 58.5 lbs./bu. for the region. Proteins reported in the 12 to 13% range. Yields are ranging from the low 20’s to the mid 40’s, with a lot of wheat trending more in the mid 20’s to mid 30’s.

Blackwell- Harvest is reported to be 85% complete. Test weights are ranging from 55 to 61 lbs./bu., with an average of 59 lbs./bu. overall. Yields reported in the mid 20’s to mid 30’s.  Proteins have ranged from 11 to 17% with an average coming in at 12.8%.

 

Northwest Oklahoma

 

Alva- Test weights reported in the ranges of 59.5 to 60 lbs./bu. Proteins are averaging 12.5%. Harvest is approximately 99% complete. Yield reports have ranged in the mid-teens to the 30’s depending on location. An occasional yield in the mid 40’s has been reported from time to time.

Shattuck-  Harvest is 80% complete. Test weights are 60 lbs./bu. or above. Yields on the dryland are averaging 10 to 15 bushels per acre. On the irrigated wheat, yields are making in the mid 30’s to the mid 60’s depending on location. The protein average was reported at 13%, although it has not been uncommon to see proteins in the 14 and 15% range. 

 

The Panhandle

 

Buffalo- Harvest did not last long in this region and is 99% complete. Yields have been reported in the mid teens to mid 20’s. Proteins have ranged from 13 to 14%. Most of the wheat was grazed or abandoned in this area due to the drought.

Hooker- Harvest on the dryland wheat is moving in full force, and is estimated 50 to 60 percent complete. Proteins averaging 13%. Test weights averaging 60.5 lbs./bu. Yields reported from 9 to as high as 25 bushels per acre for the most part. One producer reported his field of dryland wheat to have made 37 bushels per acre. No reports on irrigated wheat harvest for this week.

Keyes- Harvest is approximately 30% complete. Test weights have ranged from 57 to 62 lbs./bu. Yields have been reported from as low as 10 to as high as 30 bushels per acre depending on the location. Proteins are averaging 12.5%.

 

Northeast Oklahoma

 

Afton- Harvest is approximately 99% complete. Test weights reported from 60 to 63 lbs./bu.  Proteins ranging from 10 to 13%. This region is averaging 11.5% on protein. Yields reported from the low 30’s to as high as 70 bushels per acre. Overall the yields and quality have been favorable. 

Miami –Harvest is approximately 99% complete. Test weights reported from 60 to 63 lbs./bu.  Proteins ranging from 10 to 12.5%. This region is averaging 11.0% on protein. Yields reported from the low 20’s to as high as 70 bushels per acre. Overall the yields and quality have been favorable.

 

The final harvest report from the Oklahoma Wheat Commission will be published on Tuesday June 26, 2018.  After this week, harvest reporting will only take place in the Northern and Panhandle regions of the state.

Oklahoma Wheat Harvest Continues with Majority of Cutting Left in Northern and Panhandle Regions

Report by the Oklahoma Wheat Commission

 

The Oklahoma Wheat harvest is winding down in the Southern and Central areas of the state, with combines rolling in most parts of the northern and Panhandle regions. In the far NE part of the state around Afton and Miami, heavy rains have hindered harvest for the next couple days. Moisture was also received in central regions of the wheat belt around Marshall and Guthrie mid-morning this Tuesday. Producers are hopeful we will miss the slight chance of predicted rains tonight and tomorrow. Across the state, test weights have been favorable, with above average protein coming in from the Oklahoma/Texas line to the Oklahoma/Kansas line. Based on reports from elevator managers this week, harvest is coming in as predicted with lower than average yields. The decline in planted wheat acres as well as abandonment from the long-term drought has made this harvest progress extremely fast for producers, custom harvesters, and elevator operators. While the yields have not been as favorable as the industry would like, overall the quality of this crop looks to be encouraging for the milling and baking industries, especially when it comes to protein functionalities. The USDA June 12th Crop Production estimates for Oklahoma were unchanged from the May 10th estimate, predicting 2 million acres to be harvested with a 26 bushel per acre yield making the Oklahoma production estimate 52 million bushels for the 2018 crop.

 

Percentages of Harvest Completed Across Oklahoma

Southwest Oklahoma 99% Complete

South Central Oklahoma 98% Complete

Central Oklahoma 98% Complete

West Central Oklahoma 90% Complete

North Central Oklahoma 55% Complete

Northwest Oklahoma 55% Complete

Northeast Oklahoma 40% Complete

Panhandle 37% Complete on Dryland—No Reports on irrigated Wheat Being Harvested to date! 

Entire State of Oklahoma 77% Complete

 

For more information on winter wheat acreage, yield, and production estimates in other states, click on the USDA June Crop Production Report listed below.

https://www.nass.usda.gov/Statistics_by_State/Oklahoma/Publications/Oklahoma_Crop_Reports/2018/spr-crop-prod-06-2018.pdf

 

Southwest Oklahoma

 

Grandfield- Wheat harvest is 99.5% complete. Proteins have not been as high in this southern corridor like in other parts of Oklahoma but are still averaging around 11 to 11.5%. Test weights on the wheat have been ranging from 60 to 62 lbs./bu. Yields have ranged all over the board from as low as 15 to as high as 60 bushels per acre, depending on the location. East of Hwy 36, the yields were much higher. West of Hwy 36, yields decline the further west you move. While producers were thankful for the higher reported yields, it is important to note these higher yields will not make up for the losses and lower yields reported in this trade territory of Southwest Oklahoma overall.

Lawton- Wheat harvest is 97% complete. Test weights reported in a range from 60 to 63 lbs./bu. Protein averages reported at 11.5 to 12.5%. Yields reported from 11 to as high as 45 bushels per acre depending on the location in this trade territory.  The Eastern region in this area had some favorable yields, while the area West of Lawton had much lower yields the further west you move.

Sentinel/Rocky- Test weights have ranged from 58 to 63 lbs./bu. The overall average for test weights will range from 60 to 61 lbs./bu. Yields reported to be making anywhere from 15 to the mid- 30’s. No proteins have been reported. Harvest is estimated to be 99% complete in this area.

Clinton- Test weights have ranged from 60 to 62 lbs./bu. One field was reported to come in at 40 bushels per acre while everything else is being reported in the mid 20’s. Protein averages for the area are reported at 13%. Harvest is 75% complete. While yields have been higher than expected, collections will be way down due to abandonment of wheat acres from the drought and for other crops.

 

Central Oklahoma

 

Hinton-  Harvest is 98% complete. Test weights are averaging 60 to 63 lbs./bu. Protein average is reported at 12.5%. Yields for the most part ranging from the low 30’s to the mid 40’s. Crop production is predicted to be way down due to increased cotton and soybean acres.

El Reno- Harvest is 97% complete. Test weights are ranging from 60 to 63 lbs./bu.  Proteins reported from 11.2 to 13.9%. This region is looking at a 12% protein average.  Yields reported to be ranging from 22 to as high as 55 bushels per acre, depending on location and rainfall amounts.

KingfisherHarvest is 98% complete. Test weights reported at a 60 lbs./bu. average.  Yields are reported from as low as 5 to as high as 51 bushels per acre. Protein averages are coming in at 12.5%. Grazing did have an impact on yields in this region. Lower yields or complete abandonment start taking place on the Kingfisher/Blaine county lines, due to the severe impacts of the drought. Foreign material is significantly down from previous years, a much cleaner crop is being reported.

 

North Central Oklahoma

 

Enid- Harvest is reported to be 60% complete. Test weights are ranging all over the board, from 56 to 62 lbs./bu. depending on the variety and location. The average test weights for this area to date are 59 to 60 lbs./bu. Proteins are reported to be ranging from 11.5 to as high as 16%. Elevator locations for the most part have been saying that as harvest progresses overall we will be looking at a 12.5% protein average for the region. Yields have been reported all over the board from the mid teens to the mid 30’s.

Hillsdale- Test weights are ranging from 58 to 62 lbs./bu. Yields reported in the mid 20’s to mid 30’s. A lot of acres in this region have been abandoned due to the drought. 

Kremlin/Medford/Nardin/Nash/Renfrow- Harvest is 35 to 40% complete in these regions. Test weighs have been coming in higher than reported last week, but the current average for the area is 58.9 lbs./bu. Proteins reported in the 12 to 13% range. Yields on the wheat harvest ranging from the low 20’s to the mid 40’s.

Blackwell- Harvest is reported to be 25% complete. Test weights are ranging from 55 to 61 lbs./bu., with an average of 58 lbs./bu. overall. Yields reported in the high 20’s to mid 30’s. Proteins have ranged from 11 to 17% with an average coming in at 12.2%.

 

Northwest Oklahoma

 

Alva- Test weights reported in the ranges of 59.5 to 60 lbs/bu. Proteins are reported as an average at 12.5%. Harvest is approximately 60 to 70% complete. The majority of the wheat that is left is in lower areas that had heavy rains a few weeks ago. In some of those areas it has just started drying out for producers to get into these fields. For the most part yields are ranging in the mid 30’s, with some reports of the occasional yield in the mid 40’s.

Shattuck-  Harvest is 45% complete. Test weights are 60 lbs./bu. or above. Yields on the dryland averaging 10 to 15 bushels per acre. On the irrigated wheat yields are making in the mid 30’s. The protein average was reported at 13%, although it has not been uncommon to see proteins in the 14 and 15% range. 

 

The Panhandle

 

Buffalo- Harvest just got started this week. Yields have been reported in the mid teens to mid 20’s. Proteins have ranged from 13 to 14%. Harvest will not be long in this area as much of the crop has been grazed or destroyed due to the drought.

Hooker- Harvest on the dryland wheat is moving in full force. Harvest on the dryland wheat is estimated 30 percent complete. Proteins averaging 13%. Test weights averaging 60.5 lbs./bu. Yields reported from 9 to as high as 25 bushels per acre for the most part.  One producer reported his field of dryland wheat to have made 37 bushels per acre. No reports on irrigated wheat harvest for this week.

 

Northeast Oklahoma

 

Afton- Harvest is approximately 50% complete. Test weights reported from 60 to 63 lbs./bu. Proteins ranging from 10 to 13%. This region is averaging 11.5% on protein. Yields reported from the low 30’s to as high as 70 bushels per acre. Overall the yields and quality have been favorable. Harvest did come to a stop today with rains that came early this morning. If we miss the rains later tonight  producers are hopeful to be back in the fields in this region over the weekend.

Miami- Harvest is approximately 25% complete. Test weights reported from 60 to 63 lbs./bu.  Proteins ranging from 10 to 12.5%. This region is averaging 11.0% on protein. Yields reported from the low 20’s to as high as 70 bushels per acre. Overall the yields and quality have been favorable. Harvest did come to a stop today with rains that came early this morning. If we miss the rains later tonight producers are hopeful to be back in the fields in this region over the weekend.

 

The next harvest report from the Oklahoma Wheat Commission will be published on Tuesday June 19, 2018. After this week, wheat harvest reporting for Southern and Central Oklahoma is considered complete. The harvest report next week will only cover North Central, Northeast, Northwest and Panhandle regions.

 

Oklahoma Wheat Harvest Moves Across the State from South to North

Report by the Oklahoma Wheat Commission

 

The Oklahoma wheat harvest continues to progress in most regions of the state with the exception of far Northwestern and Panhandle areas. Early test cuttings have been accepted at Shattuck this afternoon with reports of one sample at 14.9% moisture.  Elevator managers and producers are hopeful harvest will begin in this region tomorrow. Two weeks since first cuttings were accepted down at Frederick, OK, harvest has been progressing rapidly across the state with the hot dry temperatures. Favorable proteins and test weights continue to be reported across the state, but early reports on test weights in the far northern areas of the state are coming in lower than expected on the first cuttings. Producers and elevator managers are hopeful the test weights will rise in this region and that yields will also be better as harvest progresses (harvest in the Northern regions of the state are being reported anywhere from 5 to 15% completed based on locations). While protein qualities and test weights have been promising for the most part across Oklahoma, lower yields and lack of acres with losses to cotton and other crops continue to make this an extremely fast-moving harvest. In several locations across the central and western corridors of the state from Texas to Kansas, many elevator managers have mentioned they hope to take in 10 percent of what they would in a normal year.  As of today, it looks like the May 10th USDA estimates of the Oklahoma Wheat Crop at 2 million acres with a 26 bushel per acre average for a total of 52 million bushels to be harvested in the state will be right on target. This number could come in lower than anticipated based on the increased reports of abandonment.

 

Southwest Oklahoma

 

Grandfield- Wheat harvest is 95% complete. Proteins have not been as high in this southern corridor like in other parts of Oklahoma but are still averaging around 11 to 11.5%. Test weights on the wheat have been ranging from 60 to 62 lbs./bu. Yields have ranged all over the board from as low as 15 to as high as 60 bushels per acre, depending on the location. East of Hwy 36, the yields were much higher. West of Hwy 36, yields decline the further west you move. While producers were thankful for the higher reported yields, it is important to note these higher yields will not make up for the losses and lower yields reported in this trade territory of Southwest Oklahoma overall.

Duke- Test weights reported in a range from 59 to 60 lbs./bu. Protein averages reported at 13.5%. Yields reported from the mid-teens to the mid 20’s. Harvest reported to be 60% complete.

Gotebo- Test weights reported in a range from 59 to 60 lbs./bu. Protein averages 12.5 to 13%.  Yields reported in the mid-teens to mid-20s. Harvest reported to be 50% complete.

Hobart- Test weights reported to be averaging 60 lbs./bu. Protein averages reported at 12.5 to 13%. Yields reported in the mid-teens to mid-20s. Harvest reported to be 50% complete.

Lone Wolf- Test weights reported at a 61 lbs./bu. average. Protein averages reported at 12.5 to 13%. Yields reported in the mid-teens to mid-20s. Harvest reported to be 50% complete.

Carter- Test weights reported at a 60 lbs./bu. average. Protein averages reported at 12.5 to 13%. Yields reported in the mid-teens to mid-20s. Harvest reported to be 50% complete.

Sentinel/Rocky- Test weights have been averaging 62 lbs./bu. Yields reported to be making anywhere from 13 to 30 bushels per acre. No proteins have been reported.  Harvest is estimated to be 35 to 45% complete in this area.

In most of these locations of Southwest Oklahoma, elevators are hoping to take in 10% of what they normally would due to the severe drought and loss of wheat acres to cotton acres.

 

Central Oklahoma

 

Okarche- Test weights are averaging 60 lbs./bu. Protein average is reported at 12.79%. A lot of 13 to 14% proteins have been reported, with some as high as 16.5%. Yields for the most part ranging from the mid-20s to the mid-30s with the occasional report of 40 or higher. Harvest around Okarche reported to be 50 to 60% complete.

Kingfisher/Omega- Harvest for this area is 60 to 65% completed. Test weights reported from 58 to 62 lbs./bu. Yields are reported from the mid-20s to the mid-30s. Protein averages are coming in at 12.5%. Grazing did have an impact on yields in this region. Lower yields or complete abandonment start taking place on the Kingfisher/Blaine county lines, due to the severe impacts of the drought. Foreign material is significantly down from previous years, a much cleaner crop is being reported.

Loyal- Harvest in this area is 40% complete. Test weights averaging a strong 60 lbs./bu. Yields are making in the mid-20s to the low-30s for the most part.  Protein averages coming in at 12.5%. Foreign material is significantly down in this region from previous years, a much cleaner crop is being reported.

 

North Central Oklahoma

 

Enid- Test weights are ranging all over the board, from 56 to 62 lbs./bu. depending on the variety and location. Proteins are reported to be ranging from 11.5 to as high as 16%.  Elevator locations for the most part have been saying that it has not been uncommon to see 13 to 14% protein averages for specific locations, although these numbers might not be completely representative of the overall 2018 crop since only 5 to 25% of the crop has been harvested to date in this area. Yields have been reported all over the board from the mid teens to the mid-30s.

Kremlin/Medford/Nardin/Nash/Renfrow- Early reports from what has been harvested in these locations have test weights ranging from 54.5 to 60 lbs./bu. Currently the averages from the region are coming in around that 57.5 to 58.5 lbs./bu (harvest is just starting with 5% complete). Elevators and producers in the area are hopeful test weights will pick up with the better quality wheat. Proteins  reported in the 12 to 13% range. Yields on the early harvested wheat ranging from 15 to 30 bushels per acre.

 

Northwest Oklahoma

 

Alva- Test weights reported in the ranges of 57 to 59 lbs/bu. Proteins are reported in the 12 to 13% range.

No actual yields have been reported although it is expected this area will see ranges from the mid-teens to the mid-30s depending on location and variety. It is predicted that 15 to 20% of this region is harvested.

Shattuck- At the time of this report on Tuesday morning, harvest had not started, but one sample was tested at 14.9% moisture. The test weight on that sample was 60 lbs./bu. The protein was reported at 12%. Producers are hopeful harvest will begin late Tuesday evening or on Wednesday, June 6th.

 

The Panhandle

Harvest has not begun in this region, but around the Buffalo, Guymon and Hooker regions, harvest is predicted to start on the dry-land wheat by this coming weekend.

Wheat Disease Update – May 31, 2018

This article was written by Dr. Bob Hunger, Extension Wheat Pathologist

Department of Entomology & Plant Pathology

Oklahoma State University – 127 Noble Research Center

405-744-9958

 

Wednesday through Friday (May 23-25) of last week, I was in western Oklahoma (Clinton area) and at field days in the panhandle at Goodwell and Hooker (Texas County), Keyes (Cimarron County) and Balko (Beaver County). The only disease observed of significance was indicated by white heads in fields. Often this was the result of Fusarium (dryland) root rot as reported in the last update (May 17, 2018). In fields showing this root rot, the white heads and white tillers were scattered across the field with an incidence ranging from low to moderate (Figure 1). Other fields in the panhandle exhibited large areas of not just white heads and tillers, but also white secondary tillers that had not headed. In these fields, some root rot was found, but Dr. David Marburger (OSU Small Grains Extension Specialist) and I believe that many of the white tillers/secondary tillers were the result of drought, freeze, or a combination of both. Often such tillers showed clean lower stems with no indication of root rot. We believe these secondary tillers were completely white without heading because they were sloughed off as a result of the stress from drought, freeze, or a combination of both. We suspect that more of these whiteheads will show in the coming week in northwestern OK and the panhandle, but the wheat crop is quickly turning and the whiteheads may not be as evident.

 

This likely is the last update I will be sending out this season as harvest in the southern half of Oklahoma has started with the crop quickly maturing in the northern half.

 

Figure 1.  White heads of wheat due to root rot. Typically the white heads are scattered in a field and can range from a low to high incidence. Notice in the middle photo just a few tillers of an individual plant are affected. [Credit for middle photo to Brad Babek, County Educator, Washita County]

fig1a.5.31    fig3a5.17fig3b5.17