Authored by: David Marburger and Bob Hunger
Wheat streak mosaic (WSM) was a significant disease issue for a number of producers in Oklahoma this past year (Figure 1). This disease, caused by wheat streak mosaic virus, is transmitted by the wheat curl mite (Figure 2). This mite can survive from one wheat growing season to the next on a number of different grass species, but primarily on volunteer wheat. Some like to refer to these host weeds or volunteer wheat during the summer fallow period as the “green bridge.” One of the best ways to manage this disease is controlling the wheat curl mite by eliminating the green bridge, and this can be done with tillage or a herbicide application. Since the life span of the wheat curl mite is about two weeks, volunteer wheat needs to be dead (i.e., no green tissue) for at least two weeks prior to the emergence of the newly planted wheat crop. If you spray glyphosate two weeks prior to emergence of the new wheat crop, for example, this will likely not control the wheat curl mite as the volunteer wheat will not be dead (no green tissue) for that minimum two week period.
Figure 1. Symptoms of wheat streak mosaic.
Figure 2. Wheat curl mites on a leaf surface at approximately 30-40x magnification. Source: Texas A&M.
With the current wheat prices, rain that has fallen, and rain in the forecast (trying not to jinx it here), producers especially in southern Oklahoma are going to be ready to plant by the end of August into early September to target more fall forage. In that scenario, volunteer wheat needs to be controlled right now in order to have that plant tissue dead for the minimum two week period prior to the emergence of the new wheat crop. For producers who will be planting a little later than this, there is a little bigger window for controlling that volunteer wheat yet, but it is something to keep at the top of your to-do list.
More information on wheat streak mosaic and wheat curl mites can be found in the OSU Fact Sheet EPP-7328 Three Virus Diseases of Oklahoma.
The full report for this year’s variety performance tests is now available on the wheat.okstate.edu website. You can also access it by clicking here.
I want to thank the Small Grains Extension crew, our Oklahoma State University Extension personnel, our farmer cooperators, and the participating seed companies for another successful year for the variety testing program! I also want to thank the Oklahoma Wheat Commission and Oklahoma Wheat Research Foundation for their financial support!
At the time of writing this report, 2017 Oklahoma wheat production is estimated to be approximately 89.1 million bushels, which is about 35% less than the 2016 production (Table 1) and 9% less than the 2015 production. The lower total grain production is the result of less wheat acres in the state this year. The 4.5 million planted acres was down 10% compared to the previous year, and with low wheat prices during the season, harvested acres were down as well. Number of harvested acres is estimated at 2.7 million, which is 23% less than in 2016 (Table 1). Despite the lower harvested acres, the statewide average yield is projected at 33 bu/ac. This is 6 bu/ac (18%) less than the record-tying 2016 state average but 4 bu/ac (12%) greater than the previous ten-year average.
The 2016-2017 wheat growing season can be characterized overall by periods of rainfall and near optimal growing conditions at critical times. The growing season got an early start with rainfall in late August, prompting producers interested in targeting fall forage to begin planting. Planting continued to move rapidly during early September, and most of the wheat at this time was sown into adequate soil moisture and emerged rapidly. Wheat intended for grain-only was sown during the average timeframe of early- to mid-October. A majority of the wheat sown at this time also had adequate soil moisture for good establishment, but most of the Northwest and Panhandle regions of the state were not as fortunate. Dry soil conditions in those regions resulted in suboptimal stands or no germination at all. After mid-October, little precipitation fell throughout the state for the remainder of the fall, and temperatures were above normal. Crop conditions during the early part of the growing season were rated mostly good, but with the lack of rainfall during the latter part of fall, crop conditions began deteriorating by the end of November. Fortunately, most of the wheat that was sown into adequate soil moisture was able to establish adequate above- and below-ground growth before going into winter dormancy.
Warmer than normal temperatures continued throughout much of the winter. January and February are normally very dry months for the southern Great Plains. Fortunately, much of the state received two to four inches of precipitation during mid-January. While some of the precipitation came in the form of ice in the Woodward area, it did not do much damage to the crop. It also provided the soil moisture needed for some wheat to germinate in the Northwest and Panhandle regions that had been sown in dry conditions.
With the above-average temperatures during the winter, plants broke winter dormancy ahead of normal, and spring green-up advanced quickly. The first hollow stem growth stage was reached for many varieties before the end of February, almost two weeks ahead of normal. Another round of widespread showers fell across much of the Wheat Belt on February 20, excluding the Panhandle and northeastern parts of the state. For some areas, this provided a boost to help plants recover from grazing injury. Other areas, especially south central Oklahoma, did not receive as much of this needed rainfall, and as a result, some grazed wheat pastures did not recover as well. Considering the warm temperatures during spring green-up, the prevailing thought was that much of the wheat would be mature and harvested by mid-May. However, temperatures returned to normal and slightly below normal during mid- to late-March. Many areas received another round of rainfall at the end of March, providing adequate soil moisture as the wheat crop transitioned into reproductive growth. Cool temperatures and adequate soil moisture persisted throughout heading and grain fill, favoring kernel filling. One abnormal weather event that occurred this year was a foot of snow that accumulated in the Panhandle on the last weekend in April. This did result in lodged plants and some lower test weight values, but the overall effect on yield was not as detrimental as expected at the time.
Most wheat was mature in southwestern Oklahoma by the middle of May and by the end of May in the central part 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 above average overall. Part of this variability was due to overgrazing and whether an area caught or missed a rainfall event that occurred only about every three to four weeks throughout the beginning of 2017. Field averages of 30 to 40 bu/ac were the norm across much of the state, but higher averages, even into the 60 to 70 bu/ac range, were not uncommon in some areas. 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.
Different insect pressures were a concern at times during the growing season, but few were widespread, overlapped, or season-long. Some of the wheat planted in late August into early September was hit hard by fall armyworm, and some fields had to be replanted. Dead tillers on varieties susceptible to Hessian fly showed up on early planted wheat in areas of southwest Oklahoma during mid-fall, but only a couple reports of Hessian fly were documented during the spring. The dry weather in northwest Oklahoma through the winter provided ideal conditions for winter grain mite and brown wheat mite to thrive on wheat plants coming out of winter dormancy. Aphids were not really on the radar screen of most producers until mid-March, but this turned out as not as big of a problem as has been observed in other previous years. Despite the low aphid numbers, it was not hard to find Barley Yellow Dwarf (BYD) as flag leaves and heads started to emerge. While there was quite a bit of purpling and yellowing associated with BYD, there was not as much stunting as sometimes observed with early-season transmission of the virus. Wheat Streak Mosaic (WSM), transmitted by the wheat curl mite, was a significant issue for producers around the state, but the majority of the affected areas seemed to be concentrated in areas of southwestern and northwestern Oklahoma, as well as the Panhandle region. Yield reductions were definitely apparent in fields infected with WSM.
The warm temperatures and available moisture during the fall prompted the development of some foliar diseases, primarily leaf rust. Leaf rust spores were able to survive the winter due to mild conditions, but the disease was slowed by hot temperatures and lack of available moisture during spring green-up. However, when temperatures returned to normal during mid- to late-March, the abundant inoculum present allowed leaf rust to become one of the top diseases for producers across most of the state. The presence of leaf rust during 2017 was abnormal compared to previous years as it developed sooner and persisted through grain fill while also reaching a wider geographic area. In addition to leaf rust, stripe rust was present, but at low to moderate levels in isolated areas and not as widespread throughout the state as it was in 2015 and 2016. Because of the impact that both rusts have had over the past couple years, producers were more open to apply a foliar fungicide to susceptible varieties, with many fields throughout the state receiving at least one fungicide application. Variety trial results from Apache, Chickasha, and Lahoma indicated again this year that producers were well justified in spraying many of these acres. Grain yield of the variety Bentley, for example, resulted in a 27 bu/ac increase at Lahoma when treated once with a foliar fungicide at flag leaf emergence. Our results at Lahoma also showed the power of genetic resistance to disease in varieties such as Doublestop CL Plus in which the fungicide treated plots only resulted in a 1 bu/ac increase in yield over the non-treated plots.
Oklahoma Harvest Continues in the Panhandle, Is Wrapped up in All Other Regions of the State for the Most Part
Report by the Oklahoma Wheat Commission
The Oklahoma wheat harvest is complete in most areas from the Oklahoma/Texas border to the Oklahoma/Kansas border. In the Panhandle region harvest is in full swing with producers working on the dryland wheat harvest and irrigated harvest. Yields have not been as positive in the Panhandle regions on both the dryland and irrigated wheat. A lot of dryland wheat yields have been reported in the mid 20’s with a lot of irrigated wheat yields reported in the mid 40’s to mid 50’s. Heavy rains with severe hail has also impacted areas between Boise City and Guymon. Elevators in the Panhandle region are planning on taking in approximately 50 to 55% of the crop they took in last year. Protein levels in the Panhandle region have been holding up even on the irrigated wheat for the most part. While a lot of the dryland wheat is above 12% protein even with the slightly lower percentages in the irrigated wheat, producers and elevator managers are hoping for an 11.8 to 11.9% average for the region. Test weights for the region are averaging 60 to 61 lbs./bu. Harvest around the Guymon and Hooker areas is 70 to 75% completed with harvest out by Boise City approximately 40% completed.
Report by the Oklahoma Wheat Commission:
The Oklahoma wheat harvest is complete in most areas from the Oklahoma/Texas border to the Oklahoma/Kansas border. A few machines are still moving in Northern Oklahoma but harvest in all areas of this region should be completely finished by the end of the week. In the Panhandle region harvest is in full swing with producers working on the dryland harvest. We have had some reports that harvest on the irrigated wheat is starting to happen around the Hooker area, but no yields have been reported on the irrigated wheat. Dryland wheat in the Panhandle is averaging in the mid 20’s to low 30’s depending on location for the most part.
Test weights on the dryland wheat in the Panhandle is averaging about 60 lbs./bu. Proteins on the dryland wheat in this region has been surprising with many reports coming in at 12% or higher, but elevator managers are concerned those numbers will be lower once we get into the irrigated wheat. Proteins across Oklahoma are being reported in the 10.5 to 11.5% range. Harvest has moved faster than expected in a lot of locations since producers have opted to go with other crops or have grazed out in other areas. The decrease in planted wheat acres has caught the attention of many elevator managers in the state. In many places the yields were above average but with the lower planted acres, the amount of bushels taken in at all locations across Oklahoma have been way down from last year. Many elevator locations in Southwest Oklahoma took in 50 to 60% of the bushels they had last year. As harvest progressed further North many elevator locations in that region took in 60 to 70% of the bushels they received last year.
Report by the Oklahoma Wheat Commission
Wheat harvest continues in Oklahoma moving full speed ahead in all regions. Along the Oklahoma Texas line many locations are reported to be 97 to 99% complete. Elevators in South Central Oklahoma are reporting harvest to be 75 to 90% complete depending on the location, while parts of Central Oklahoma are 95% harvested. As harvest has moved forward in Northern Oklahoma some locations have reported harvest to be 75% complete along the I-35 corridor. In Northwest Oklahoma reports of harvest completion are ranging from 35% to 50% depending on location.
In some locations producers were able to get back into the fields last Tuesday, but in all areas since Thursday because of the open weather, producers and custom harvesters have been able to take advantage of getting the crop out in record speed since they have started rolling. Test weights across the state have dropped in most locations, but as of today many locations are still reporting 60 lbs./bu. averages. Yields across the state have been ranging all over the board depending on the management, heavy rains and hail damage. Across Southwest Oklahoma, we have heard of yields ranging from the mid teens to the mid twenties, with also better yields in some areas of this region reported to be in the mid 30’s to mid 40’s. The same is holding true for Central and Northern Oklahoma. As we have moved into Northern Oklahoma, we have been hearing higher yields in the mid 40’s to 50’s with many reports of wheat in some locations to be making anywhere from the mid 60’s to mid 70’s.
Harvest has moved faster in Southern Oklahoma due to many of the wheat acres going into cotton. We are also hearing reports in Northern Oklahoma that even though the yields are high the number of bushels will not be taken in because of the other summer crops that producers are opting to go with right now. Proteins across Oklahoma are being reported in the 10.5 to 11.5% range. We have had some reports on some proteins as high as 13% in North Central Oklahoma.
Report by Locations:
Grandfield – Harvest reported to be 99% complete. A lot of the wheat in this region was heavily grazed. Due to the heavy rains and hail, they are seeing yield reports making in the mid 20’s to mid 30’s with the occasional 40+ yield. Test Weights reported from 59 to 61 lbs./bu.
Chattanooga – Harvest reported to be 99% complete. A lot of the wheat in this region was heavily grazed and due to the heavy rains and hail, they are seeing yield reports making in the mid 20’s to mid 30’s. Test weights reported from 59-61 lbs./bu.
Lone Wolf – Harvest in this region reported to be 90% complete. The test weights in this region have been averaging 59- 60 lbs./bu. Yields in the region ranging from the mid 20’s to the mid 30’s, with reports of some wheat making better than 40 bushels per acre.
Hobart – Harvest in this area is reported to be 85% complete. The test weights in this region have been averaging 58-60 lbs./bu. Yields in the region ranging from the mid 20’s to the mid 30’s with some wheat in the region reported to be making in the mid 40’s.
Granite – Harvest in this region reported to be 90% complete. Test weights in this area have been doing remarkably well, ranging from 60 to 64 lbs./bu. Yields in this region also reported to be higher with reports of a lot of wheat making in the mid 40’s to mid 50’s.
Hinton – Harvest in this area is reported to be 75% complete. Test weights in this region have been averaging 58 to 60 lbs./bu. Yields have been reported all over the board from as low as 10 to as high as 60. A lot of wheat in this region was reported to be making in the mid 30’s to mid 40’s.
Okarche – Harvest in this region is reported to be 95% complete. Test weights in this region were reported to be averaging 60lbs./bu. Yields in this area also have been reported all over the board from as low as 10 to as high as 50. A lot of reports of wheat in the region was stated to be making in the mid 30’s to mid 40’s as an average.
Hennessey – Harvest in this region is reported to be 75% complete. Test weights in this region have been lighter due to the heavier rains, this area for the most part is looking at 58 to 59lbs./bu. average. Yields in the region are reported all over the board depending on the weather and management practices. A lot of wheat was reported to be making in the mid 30’s to mid 40’s, while some yields were lower due to hail.
Perry – Harvest moved quickly over the weekend in this region and elevator managers are calling it 75% complete. Test weights have gotten lighter with the rains. Currently the average test weight for the region is 59lbs./bu. Yields have been reported all over the board, with reports as low as 10 on hail damaged wheat, and other reports with yields as high as 60. We have had a lot of reports of wheat making in the mid 40’s to mid 50’s in this region.
Braman – Harvest in this region is just getting started and would be considered 30% complete. Test weights in the region are averaging 59 lbs./bu. Yields in this region are reported from the mid 30’s to the mid 50’s.
Cherokee – Harvest in this region is approximately 50% complete. Test weights in this area have been reported all over the board and have been lowered due to the rains from last week. The area is still hoping for a 58 to 59lbs/bu. average on test weight, although lower weights have been reported. Yields in this region have been all over the board with reports on damaged wheat to be making in the mid 30’s, while higher yielding wheat has been reported to be making in the low to mid 70’s.
Alva – Harvest in this region is reported to be 35 to 40% complete. Test weights for the region are averaging 58 lbs./bu. Yields have been reported all over the board from the mid 20’s to as high as 60 bushels per acre.
Shattuck – This location just got started with harvest yesterday. They reported to take in 60,000 bushels at CGB at this location. Test weights were ranging from 62 to 63 lbs./bu. No yields have been reported from the region, but it is reported that yields will range from the mid 20’s to mid 40’s for the most part.
Hooker – No wheat has been taken in at this location in the Panhandle. It is predicted that harvest will begin towards the end of the week at this location.
Report by the Oklahoma Wheat Commission
Wheat harvest continues to move from Southern Oklahoma with locations on the Oklahoma/Texas State Line reporting to be 95 to 97% complete, while harvest is just starting in locations on the Oklahoma/Kansas state line. Rain has hindered harvest from progressing across the state this past weekend with rain showers also impacting producers last night in many locations across the Western half of Oklahoma. The wet conditions with high humidity has made it difficult for producers to get early starts cutting even where the ground was dry enough to carry the combines yesterday afternoon.
Rain averages last night were reported by many locations to be anywhere from .1 inches to over 2 inches depending on the location with the Mesonet reporting only .04 inches in some parts of Oklahoma on the Oklahoma/Texas line. Over the weekend some parts of Western Oklahoma had locations that received anywhere from 4 to 7 inches of moisture right before the wheat was ready to cut. Test weights have dropped in many areas across Oklahoma, and some producers are concerned they will have lost another pound after the rains last night. Fortunately, the test weights were starting out this harvest extremely high. Many elevator locations, as of today, are still hoping for a 60 lbs./bu. average, with some locations starting to report test weights ranging in the 58 to 59 lbs./bu. range. It has been stated that we have two crops in the field since many producers opted for later plantings in Central and Northern Oklahoma based on other crop rotations they have been using. This, and the cooler temperatures, have been helpful on test weight up to this point for the crop that is left in the field to be harvested. Yields across the state have been ranging all over the board depending on management, heavy rains and hail damage. Across Southwest Oklahoma, we have heard of yields ranging from the mid teens to the mid twenties, with also better yields in some areas of this region reported to be in the mid 30’s to mid 40’s. The same is holding true for Central and Northern Oklahoma. As we have moved into Northern Oklahoma, we have been hearing higher yields in the mid 40’s, with some reports of wheat being in the mid 50’s. Many elevator managers are hopeful we will have later wheat coming in with yields higher if we can just get ahead of the rains. One thing impacting the amount of bushels being taken in at all locations is the amount of wheat acres that have gone into other crops; whether it be cotton, canola, sesame, soybeans or hay. We have also seen acreage decline for larger amounts of the crop being grazed out early this spring. In parts of Southwest Oklahoma, elevators plan on taking in 50 to 60 percent of the bushels they would normally take in based on the acres that are being planted to cotton. Elevators in North Central Oklahoma have been making the same comments based on producers opting for other options with canola and soybeans.
Report by Locations:
Grandfield-Harvest reported to be 95 to 97% complete A lot of the wheat in this region was heavily grazed. Due to the heavy rains and hail they are seeing yield reports making in the mid 20’s to mid 30’s with the occasional 40+ yield. Test Weights reported from 59 to 61 lbs./bu.
Chattanooga- Harvest reported to be 95 to 97% complete. A lot of the wheat in this region was heavily grazed and due to the heavy rains and hail, they are seeing yield reports making in the mid 20’s to mid 30’s. Test weights reported from 59-61 lbs./bu.
Lone Wolf- Harvest in this region reported to be 85% complete. The test weights in this region have been averaging 60 lbs./bu. Yields in the region ranging from the mid 20’s to the mid 30’s with reports of some wheat making better than 40 bushels per acre.
Hobart- Harvest in this area is reported to be 85% complete. The test weights in this region have been averaging 60 lbs./bu. Yields in the region ranging from the mid 20’s to the mid 30’s with some wheat in the region reported to be making in the mid 40’s
Granite- Harvest in this region reported to be 85% complete. Test weights in this area have been doing remarkably well, ranging from 60 to 64 lbs./bu. Yields in this region also reported to be higher with reports of a lot of wheat making in the mid 40’s to mid 50’s
Rocky- Harvest in this region is reported to be 50% complete. The rains over the weekend and last night have producers in this region at a standstill, with hopes they will be able to get back into the fields hopefully on Friday. Test weights in this region are ranging from 58 to 60 lbs./bu. Prior to the rains, a lot of wheat was taken in at this location with test weights ranging from 62 to 64 lbs./bu. Yields in this region are reported to be making in the mid 30’s for the most part.
Sentinel- Harvest was progressing yesterday with combines planning to continue today since the rains were missed last night. Test weights in this region reported from 59 to 60 lbs./bu. Yields have not been reported since harvest in the area is just beginning.
Greenfield- Before Friday, test weights in the region were coming in extremely high with most weights ranging from 63 to 64 lbs./bu. It is estimated 1/3 of the crop is harvested in this area. The rains over the weekend and last night have placed harvest at a standstill with the hopes producers will be able to get back into the fields by Friday at the earliest. Some wheat was harvested in the region late yesterday afternoon with test weights ranging from 59 to 60 lbs./bu. Yields in the region reported to be making anywhere from the mid 20’ to the mid 50’s.
Kingfisher- After the weekend rains, producers started harvesting again in parts of this region yesterday afternoon. In many parts of this area the rains went West so producers will be harvesting in the area this afternoon as well. Test weights, as of yesterday, were ranging for the most part, from 59.5 to 60 lbs./bu. Yields are reported all over the range from the mid 20’s to the mid 40’s, depending on the rains and hail damage. Some reports indicate a few producers had some yields in the mid 50’s before the rains this past weekend.
Helena– Harvest in this region has started with a couple of producers cutting. Test weights on the 3,000 bushels that has been taken in is reported in the range of 60 to 61 lbs./bu. No yields from the area have been reported.
Pond Creek- Harvest has just begun in this region. Test weights are ranging from 58 to 61 lbs./bu. Producers in this area are hoping to get moving at full speed this afternoon. No yields have been reported on early cuttings, but some of the wheat in this area still looks very favorable.
Tonkawa- Harvest in this region is just getting started. Test weights in the region are averaging so far 60 to 61 lbs./bu. One producer figured he was making in the mid 50’s. Indications are a lot of the wheat looks favorable in this region, although many acres within the area also had significant hail damage, depending on where the storms hit.
Burlington- Harvest just started in this region yesterday. Some producers will most likely cut this afternoon, while others will be out of the field for the next couple of days, due to the rains last night. 30,000 bushels have been hauled into Burlington so far. Test weights are decent with a 60lbs./bu. average reported. No yields have been reported, but producers are hopeful the yields will be decent if they can get into the fields without more rain.
Shattuck- No wheat has been taken in at this location, but producers are hopeful harvest will get started in this region by the weekend.
Hooker- No wheat has been taken in at this location in the Panhandle. The cooler temperatures in the region have slowed the ripening. Many producers think harvest in the area is at least 6 to 10 days away.
Report by the Oklahoma Wheat Commission
Wheat producers across Southwest and Central Oklahoma had combines moving at full speed over the Memorial Day weekend. Yields in parts of Southwest Oklahoma were lowered by heavy rains and hail that passed thru the state over a week ago. In other places the crop has been fairing with decent yields and high test weights up to this point. Elevator managers have been reporting the significant loss of wheat acres to be impacting the speed of harvest in Southwest Oklahoma. This is making the season seem to go much faster. Several managers have been reporting they expect to take in 50 to 60 percent of the bushels in this region they normally take due to the increase in planted cotton acres.
In Central Oklahoma the crop harvest is also progressing with decent yields and test weights reported in most areas. Producers also have had issues with hail damage West and East of Kingfisher. Many elevator managers have stated we have a decent quality crop overall, if we can just get to it before we receive more rainfall. The 7 day forecast of more predicted rains have many producers concerned about what lies ahead for this harvest season all across the state. Proteins across Texas on up into central Oklahoma are being reported in the 10.5 to 11% range.
Grandfield-Harvest reported to be 65% complete. A lot of the wheat in this region was heavily grazed and due to the heavy rains and hail they are seeing a lot of yield reports to be making in the mid 20’s to mid 30’s with the occasional 40+ yield. Test Weights reported from 59 to 61 lbs./bu.
Chattanooga- Harvest reported to be 50 to 55% complete. A lot of the wheat in this region was heavily grazed and due to the heavy rains and hail they are seeing a lot of yield reports to be making in the mid 20’s to mid 30’s. Test weights reported from 59-61 lbs./bu.
Lawton- Harvest reported to be 50% complete. The wheat in this area has been having better yields ranging from the mid 20’s to the mid 40’s. Test weights in this area are averaging 61 lbs./bu.
Altus- Harvest in this region reported to be 60% complete. The test weights in this region have been averaging 60 to 63 lbs./bu. Yields in the region reported from the mid 20’s to the mid 40’s. Overall the visual quality is reported to be very favorable from this region.
Lone Wolf- Harvest in this region reported to be 45% complete. The test weights in this region have been averaging 60 lbs./bu. Yields in the region ranging from the mid 20’s to the mid 30’s with reports of some wheat making better than 40 bushels per acre.
Clinton- This region is just getting started as of yesterday. No yields have been reported but the test weights on what has come in so far is averaging 60 lbs./bu.
Rocky- Harvest in this region has been progressing slowly. Yesterday, was considered to be a decent day for the area with more wheat reported to be coming in. Test weights reported at 60 to 61 lbs./bu. Yields reported to be making in the mid 30’s for the most part.
El Reno- Harvest in this region has been moving steady over the Memorial Day weekend, with producers just getting a good start in this area. Yields in the region from early reports indicate the crop is doing well coming in with a lot in the range of the mid 40’s. Test weights reported to be making anywhere from 61 to 63.5 lbs./bu.
Kingfisher-Harvest is just beginning in this region with a few reports of wheat harvest beginning to start around Loyal and Omega. Test weights in the region being reported in the 58 to 63 lb./bu. range. Yields have been ranging all over the board in this region, with reports of wheat making anywhere in the mid 20’s to mid 40’s for the most part. A few reports that some producers in the region have been making in the mid to high 50’s.
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 – email@example.com
This past week I traveled and looked at wheat in north-central/northwestern OK at Alva and Cherokee, as well as wheat in the panhandle. I also looked at wheat here around Stillwater and in central OK near Kingfisher/Okarche (30-35 miles northwest of OKC). Wheat in central OK and around Stillwater is or quickly will be ready for harvest, weather permitting. Wheat across northern OK (Cherokee and Alva) was quickly approaching maturity, but kernels were still soft and some green was still present in stems/heads. Wheat in the panhandle ranged from ¼ to full kernel, with stems and leaves still quite green in many varieties.
Leaf rust is still active in the panhandle area, and samples testing positive for Wheat streak mosaic virus, High plains virus, and Barley yellow dwarf virus continue to come to the Diagnostic Lab. In some fields I saw (and in talking to producers), it is difficult to see where the mites/virus originated, but grassy weeds and perhaps volunteer crops such as sorghum or corn may be the most likely source. For more information on mite-transmitted wheat viruses such as WSM, please see OSU Fact Sheet EPP-7328 (Wheat Streak Mosaic, High Plains Disease, and Triticum Mosaic: Three Virus Diseases of Wheat in Oklahoma) available at http://wheat.okstate.edu/wheat-management/diseasesinsects/EPP-7328.
One abiotic disease (a disease not caused by a pathogen) that is being reported is a head darkening or head melanism (Figure 1). Reports of this darkening have come from southwestern and central OK, as well as from northern OK around Blackwell/Tonkawa/Ponca City.
Figure 1. Head darkening (melanism) as seen in the Lahoma variety trial in late May.
Although this darkening has been observed in several varieties, it seems to be most noticeable in the variety Bentley. Dr. Carver had noticed a head darkening in Bentley prior to its release, but apparently environmental factors this year have caused it to be expressed more strongly than in years prior. One of the parents of Bentley is TAM 303, which was developed by Dr. Jackie Rudd at Texas A&M University. Dr. Rudd sent the following information: “Bentley has the same “fluorescent” green glumes early and dark red/brown chaff color at maturity as TAM 303 which is one of it’s parents. TAM 303 and many of it’s descendants normally have 1-2% of near black heads that look like your photos. Most are sterile or have a few shriveled seeds. This is not an impurity, and is expressed more in some environments than others. It is sometimes spotty in a field and sometimes scattered throughout. Our take on it was that it was just a concentration of the unique TAM 303 glume color in sterile heads- whatever might have caused the sterility. Freeze related sterility is a common culprit for us. For us, almost all TAM 303 derived lines that have the fluorescent green heads, would also have some of these black heads if we had sterility.” Dr. Carver has indicated that during the development of Bentley, he took seed from dark heads and planted that seed to see if there was any effect on the next generation of wheat plants. He did not see any effect on the next generation either in wheat yield or in the incidence of dark heads. However, in some environments seed from darkened heads may not be as plentiful or “full” as seeds from non-darkened heads (Figure 2).
Figure 2. Seed taken from a dark and non-dark head of Bentley wheat.
In summary, this head darkening that has been observed in Bentley and other varieties appears to affect seed yield and kernel filling, and is related to the genetics of the variety that is induced by an unknown stress or combination of stresses.