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First hollow stem nearing

First hollow stem occurs just prior to jointing and is the optimal time to remove cattle from wheat pasture. Given the warm forecast for the next two weeks, it is likely that we will start seeing first hollow stem in Oklahoma wheat fields. Grazing past first hollow stem can reduce wheat grain yield by as much as 5% per day and the added cattle gains are not enough to offset the value of the reduced wheat yield.

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

Checking for first hollow stem is fairly easy.

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

Checking for first hollow stem

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

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

Checking for first hollow stem is fairly easy.

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

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

2014 Wheat Crop Overview

This blog post is an excerpt from the 2014 OSU Small Grains Variety Performance Tests report, which is available at http://www.wheat.okstate.edu or by clicking here.

At the time of writing this post, 2014 Oklahoma wheat production is estimated to be approximately 51 million bushels, which is roughly half of 2013 production (Table 1). Oklahoma has not seen wheat production this low since the 43 million bushel crop of 1957, and with any luck, production will not be this low again for at least another 60 years.

 

Table 1. Oklahoma wheat production for 2013 and 2014 as estimated by OK NASS, July 2014
2013 2014
Harvested Acres 3.4 million 3.0 million
Yield (bu/ac) 31 17
Total bushels 105 million 51 million

 

The 2013-2014 wheat production season had a good start in central Oklahoma. Topsoil moisture was short in September, but October rains resulted in favorable conditions for wheat emergence and establishment. In addition, many areas had a fair amount of stored soil moisture from the summer of 2013. This stored soil moisture allowed sites such as Chickasha and Lahoma to produce 43 and 47 bu/ac average wheat yield on less than eight inches of rainfall during the growing season. Stored soil moisture also contributed to adequate forage production at grazed sites such as Marshall Dual-Purpose, but production of a forage crop did not leave behind enough moisture to fuel much of a grain crop.

 

The multi-year drought never released its stranglehold on western Oklahoma during the 2013-2014 wheat production season. Small rains here or there allowed most producers to obtain an acceptable stand of wheat, but moisture was never sufficient to spur tillering or leaf area development. Early winter snowfall made for a few bright spots for forage production in southwestern Oklahoma, but this moisture was quickly utilized by growing wheat plants and dry conditions soon returned. As a result, many fields in southwestern and western Oklahoma were abandoned and not taken to harvest.

This photo of a wheat field near Altus, Oklahoma in April 2014 shows the level of devastation from the extreme, multi-year drought. Most wheat fields in this region were abandoned due to drought.

This photo of a wheat field near Altus, Oklahoma in April 2014 shows the level of devastation from the extreme, multi-year drought. Most wheat fields in this region were abandoned due to drought.

 

Thin wheat stands left some fields vulnerable to blowing sand and wind erosion

Thin wheat stands left some fields vulnerable to blowing sand and wind erosion

The winter of 2013-2014 wasn’t just dry; it was cold too. Young, drought-stressed wheat plants had difficulty dealing with the cold, windy conditions, and winterkill was common in late-sown wheat. Winterkill was also common in grazed wheat that was stressed by heavy grazing pressure and inadequate soil moisture. Considerable winterkill was also present in no-till wheat without adequate seed to soil contact in northwestern Oklahoma. The inadequate seed to soil contact was generally the result of heavy residue from the previous year’s wheat crop.

Winterkill was common in northwestern Oklahoma, with the greatest injury occurring in no-till and/or grazed wheat fields.

Winterkill was common in northwestern Oklahoma, with the greatest injury occurring in no-till and/or grazed wheat fields.

Closer inspection of some no-till fields with winterkill revealed shallow seed placement due to heavy and/or unevenly spread residue from the 2103 wheat crop.

Closer inspection of some no-till fields with winterkill revealed shallow seed placement due to heavy and/or unevenly spread residue from the 2103 wheat crop.

 

While the wheat crop did not appear to be on its way to bumper production, most producers hoped for a turnaround similar to 2013 and topdressed in late winter. Unlike the spring of 2013, however, the rains never came and much of this topdress N applied did not make it into the soil until the crop was at boot stage or later.

 

The cold winter delayed the onset of first hollow stem by about five days as compared to 2013 and 25 days as compared to 2012. Despite a slow start to the spring, wheat in southern Oklahoma was near heading when a hard freeze occurred the morning of April 15, 2014. As expected, drought stressed wheat in advanced stages in southwestern Oklahoma suffered severe freeze damage; however, injury from the 2014 spring freeze did not always follow the “rule of thumb” guidelines used by agronomists. Many areas that received small amounts of rain just prior to the freeze seemed to escape widespread injury, regardless of growth stage. In southcentral Oklahoma, injury seemed to be most severe on later maturing varieties that were approximately Feekes GS 7 to booting, while earlier-maturing varieties that were just starting to head escaped freeze injury. Wheat that was barely past two nodes in northern Oklahoma suffered severe injury, while more advanced wheat in central Oklahoma endured similar temperatures with minimal injury.

 

There were relatively few insect or disease issues to deal with during the 2013-2014 wheat production season. Winter grain mite and/or brown wheat mite infestations proved to be too much for some drought stressed wheat fields in northcentral and northwestern Oklahoma. Some fields already devastated by the drought were left unsprayed, while others still showing some sign of yield potential were treated.

 

Injury, such as the bronzed areas in the picture above, was the result of brown wheat mite and/or winter grain mite infestations in late winter.

Injury, such as the bronzed areas in the picture above, was the result of brown wheat mite and/or winter grain mite infestations in late winter.

 

Other than a rare siting of a single leaf rust pustule, there was no foliar disease in Oklahoma in 2014. The lack of foliar disease is evidenced by the lack of response to foliar fungicides at either Chickasha or Lahoma. These two sites provided a rare opportunity in 2014 to observe yield impacts of foliar fungicides in the absence of disease, as most years we report at least light or negligible foliar disease at these sites. While foliar disease was not an issue in 2014, wheat streak mosaic virus was an issue for many producers. This disease has historically been most prevalent in northwestern Oklahoma and the Panhandle. Wheat streak mosaic virus was confirmed in several fields downstate this year, however, and it is likely that some fields affected by wheat streak mosaic virus were not identified as such because it is sometimes difficult to distinguish wheat streak mosaic virus symptoms from those of severe drought stress. The wheat variety testing program was not immune from this disease, and we lost our Kildare location to wheat streak mosaic virus.

 

Warmer temperatures in May hastened crop maturity and the Oklahoma wheat harvest began near Frederick on May 22, 2014. By the first week of June, harvest was in full swing, only to be delayed by rain shortly thereafter. Harvest resumed across most of the state by June 13 and was mostly completed by June 30. The exceptions being some waterlogged areas in northern Oklahoma. The Cherokee Mesonet site, for example, reported 5.1 inches of rainfall from October 1, 2013 to May 31, 2014, but the same site received 10 inches of rain from June 1 to June 30, 2014.

Harvest underway

The 2014 Oklahoma wheat harvest is underway and results from the Walters and Thomas wheat variety trials are now posted at http://www.wheat.okstate.edu. Depending on field operations, I usually get variety trial results posted on the web within a day or two of harvest.  The best way to learn when results are posted are to follow me on Twitter @OSU_smallgrains or subscribe to our Extension news list serve (send me an email at jeff.edwards@okstate.edu to be added to the listserv).

I have posted a few pics from our harvest operations below.

 

Wheat checkoff dollars make the Oklahoma Wheat Variety Testing program possible. We appreciate the support of our Oklahoma farmers!

Wheat checkoff dollars make the Oklahoma Wheat Variety Testing program possible. We appreciate the support of our Oklahoma farmers!

Harvest at Walters, OK. Photo courtesy Todd Johnson, OSU Ag. Comm. Services.

Harvest at Walters, OK. Photo courtesy Todd Johnson, OSU Ag. Comm. Services.

Changing tires on the side of I-35 is never fun. We blew two more on the way to Thomas the next day and damaged the trailer. Big shout out to Eley's service center in Watonga and Watonga  Machine and Steel for getting us back on the road. Don't get me started on the lack of American made trailer tires!

Changing tires on the side of I-35 is never fun. We blew two more on the way to Thomas the next day and damaged the trailer. Big shout out to Eley’s service center in Watonga and Watonga Machine and Steel for getting us back on the road.

Once we made it Thomas harvest went well. Yields were low, but that was to be expected given the freeze and drought.

Once we made it Thomas harvest went well. Yields were low, but that was to be expected given the freeze and drought.

2013-2014 Wheat fall forage variety trial results

This blog post is an abbreviated posting of our wheat forage results. For the complete report, consult OSU Current Report 2141 Fall forage production and date of first hollow stem in winter wheat varieties during the 2013-2014 crop year by clicking here.

Average daily temperature and rainfall for Stillwater, OK from 09/01/2013 to 03/31/2014

Average daily temperature and rainfall for Stillwater, OK from 09/01/2013 to 03/31/2014

Average daily temperature and rainfall for Chickasha, OK from 09/01/2013 to 03/31/2014

Average daily temperature and rainfall for Chickasha, OK from 09/01/2013 to 03/31/2014

As was the case across most of Oklahoma, our wheat plots were sown into dry topsoil in late September. Soils in southwest and northwest Oklahoma were extremely dry due to multiple years of drought, and wheat pasture was short in these areas of the state. Summer rainfall provided ample subsoil moisture in the central part of the state, but topsoil was largely dry through September. Rains fell across much of the state in October and provided the fuel needed to build wheat pasture. Unfortunately, these October rains would be the only significant rainfall events most of the Oklahoma wheat crop would receive .

 

Fall forage production by winter wheat at Stillwater and Chickasha averaged 3,240 and 2,580 pounds per acre, respectively (Tables below). There was a large group of varieties at Stillwater and Chickasha that produced statistically equivalent forage yield, and producers are encouraged to consider two and three year averages when available.

 

 

Table 2. Fall forage production by winter wheat varieties at Stillwater, OK during the 2013-2014 production year.
Source Variety  2013-2014  2-Year  3-Year
 —————lbs dry forage/acre—————-
Syngenta SY Llano 4,100
AGSECO TAM 113 4,090 3,160 3,220
OGI Billings 3,850 3,200 3,250
LCS LCS Mint 3,690
OGI Duster 3,670 3,180 3,300
OGI Gallagher 3,650 3,230 3,500
LCS T154 3,640 3,040
Syngenta Doans 3,610
WestBred WB4458 3,610 2,920
Syngenta Jackpot 3,600 3,060 3,150
WestBred WB-Cedar 3,560 3,240 3,250
OSU Deliver 3,470 2,770 3,010
WestBred Winterhawk 3,470 2,780 3,020
OGI Garrison 3,350 3,100 3,210
Watley TAM 112 3,230
OGI Doublestop CL Plus 3,200 3,020
OGI Pete 3,160 2,810 3,020
Syngenta CJ 3,130 2,810 2,980
LCS LCH08-80 3,120 2,950
WestBred Armour 3,110 3,000 3,100
LCS LCH11-1117 3,110
OGI Centerfield 3,090 2,820 3,120
OGI OK Bullet 3,090 2,630 2,820
Syngenta SY Southwind 3,090
OSU Endurance 3,080 3,080 3,310
KWA Everest 3,050 2,810 3,010
Syngenta Greer 3,040 2,840 2,960
LCS LCH11-1130 3,040
LCS T158 3,020 2,760 3,000
CWRF Brawl CL Plus 2,980 2,860
OGI Ruby Lee 2,980 2,610 2,900
LCS T153 2,960 2,840 3,090
OGI Iba 2,930 2,770 3,030
WestBred WB-Grainfield 2,910 2,920
WestBred WB-Redhawk 2,850 2,590
LCS LCH11-109 2,750 2,990
OGI OK Rising 2,720 2,720
CWRF Byrd 2,670 2,590
OSU Experimentals
OK09125 2,800 2,540
LSD (0.05) 750 500 400

 

Table 3. Fall forage production by winter wheat varieties at Chickasha, OK during the 2013-2014 production year.
Source Variety 2013-2014  2-Year
–lbs dry forage/acre–
OGI Duster 2,920 2,920
OGI Gallagher 2,920 3,010
LCS T158 2,900 2,580
CWRF Brawl CL Plus 2,830
KWA Everest 2,750 2,750
OGI Doublestop CL Plus 2,700
WestBred Winterhawk 2,680
LCS LCS Mint 2,660
OSU Endurance 2,630 2,620
WestBred WB-Cedar 2,590 2,630
CWRF Byrd 2,540
Syngenta Jackpot 2,540 2,460
WB-Grainfield WB-Grainfield 2,530
WestBred WB4458 2,520
OGI Iba 2,460 2,460
LCS LCH08-80 2,440
OGI Billings 2,420
OGI Ruby Lee 2,420 2,430
OSU Deliver 2,410 2,200
Syngenta Greer 2,380 2,480
Syngenta Doans 2,210
OGI Garrison 2,160 2,220
OSU Experimentals
OK09125 2,760
Average 2,580 2,560
LSD 430 290

First hollow stem data are reported in ‘day of year’ (day) format (table below). To provide reference, keep in mind that March 1 is day 60. Average occurrence of first hollow stem at Stillwater in 2014 was day 77. This was approximately five days later than 2013 and 25 days later than in 2012 and was the result of much cooler than normal temperatures. Unlike previous years, there was only about ten days difference among varieties in occurrence of first hollow stem.

Table 4. Occurrence of first hollow stem (day of year) for winter wheat varieties sown in 2013 and measured in 2014 at Stillwater, OK
Source Variety Stillwater
–day of year–
Syngenta SY Llano 72
WestBred WB-Cedar 72
OGI Billings 74
Syngenta CJ 74
KWA Everest 74
OGI Gallagher 74
Syngenta Jackpot 74
OGI OK Bullet 74
OGI OK Rising 74
Syngenta SY Southwind 74
LCS T153 74
Watley TAM 112 74
AGSECO TAM 113 74
WestBred Armour 77
CWRF Byrd 77
OSU Deliver 77
Syngenta Doans 77
OGI Duster 77
OSU Endurance 77
OGI Garrison 77
Syngenta Greer 77
LCS LCH11-109 77
LCS LCH11-1117 77
LCS LCH11-1130 77
LCS LCS Wizard 77
OGI Pete 77
LCS T154 77
WestBred WB-Redhawk 77
WestBred WB4458 77
WestBred Winterhawk 77
OGI Doublestop CL Plus 80
OGI Iba 80
LCS LCS Mint 80
OGI Ruby Lee 80
LCS T158 80
WestBred WB-Grainfield 80
CWRF Brawl CL Plus 83
OGI Centerfield 83
OSU Experimentals
OK11754WF 69
OK10728W 74
OK09520 77
OK08707W-19C13 80
OK09125 83
OK10805W 83
OK10126 86
Average 77

First hollow stem nearing

First hollow stem occurs just prior to jointing and is the optimal time to remove cattle from wheat pasture. Given the warm forecast for the next two weeks, it is likely that we will start seeing first hollow stem in Oklahoma wheat fields. Grazing past first hollow stem can reduce wheat grain yield by as much as 5% per day and the added cattle gains are not enough to offset the value of the reduced wheat yield.

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

Checking for first hollow stem is fairly easy.

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

Get to know the OSU Wheat Variety Testing Program

It occurred to me the other day that although I have publicized the forage, grain, and quality results from the OSU Wheat Variety Testing Program, I have never really given much effort to publicizing the day to day activities required to produce these results. So, over the next year I hope to write a few blogs to provide a little more insight into the workings of the system.

Location, location, location
Our program will have replicated trials at 23 sites in 2013/2014. These sites cover the state from Afton to Altus and McLoud to Keyes and some sites (e.g. Apache, Lahoma, Chickasha, Goodwell) have multiple trials. The location of trials are decided upon by throwing darts at a map (just kidding). We pick trial locations according to many factors including: visibility, uniformity, production history, local support, and cooperator involvement. Some locations (e.g. Lamont) have been in the system from the start, and others (e.g. McLoud) are fairly new additions. Given the miles between locations and a finite number of planting and harvest days, 23 locations is about the maximum we can handle and still complete operations in a timely fashion.

In addition to the small, replicated plots we organize and distribute ten-pound demonstration bags for County Educators. We typically have about 40 sets of 15 varieties for these ten pound “demo sets”.

OSU wheat variety testing locations cover Oklahoma from Afton to Altus and McLoud to Keyes. The Kingfisher location shown in this picture, also includes Dr. Carver's elite nursery of advanced experimental lines

OSU wheat variety testing locations cover Oklahoma from Afton to Altus and McLoud to Keyes. The Kingfisher location shown in this picture, also includes Dr. Carver’s elite nursery of advanced experimental lines

Who pays for all this?
The bulk of the expense of running the program comes in the form of salary, facilities, and miscellaneous overhead expenses and is largely covered by OSU through state appropriations (i.e. Oklahoma taxpayers). The bulk of the day to day operating expenses, such as seed, fuel, and mileage expenses, are covered through grants from the Oklahoma Wheat Commission and Oklahoma Wheat Research Foundation (i.e. Oklahoma wheat farmers). These two organizations also help with large equipment purchases such as tractors and combines. A relatively new area of support for the program is an entry fee system. The $500 per variety fee helps offset increasing expenses and is generally enough to assist with student labor for the project. We typically employ one or two graduate students and one or two undergraduate workers. Yes, we charge licensees for testing released OSU varieties but do not charge for OSU experimental lines.

Little packets of seed
Once we have determined which varieties will go at each location, we will send seed requests to participating companies. If everything goes well, we will receive seed in late August. We request one bag of most varieties and eight bags of varieties that will be included in the county demonstration packets.

Depending on the location, there are 25 to 45 varieties replicated four to eight times at each site. Each one of these plots starts with an envelope with either 60 (grain only) or 120 (dual purpose) grams of seed (120 grams is approximately 1/4 pound). This creates a total of about 4,000 envelopes that are weighed and packaged by hand each year. Envelopes are sorted according to a plot plan which randomly assigns varieties to locations within the field at each site. The plots plans are all created one at a time in Excel.

Planting five feet at a time
We have two planters. Our conventional planter sows eight six-inch rows and our no-till planter sows seven 7.5-inch rows. Seed is dropped into the distribution cone and released in the five foot alley between replications/blocks. A gear box is used to adjust the length of row over which the seed will be distributed. We work the ground with a small field cultivator at some locations and the producer or station manager works the ground for us at others.

Robert Calhoun and Matt Knori sow the 2013/2014 wheat variety test plots at Alva, OK. Robert is dropping a 60 gram envelope of seed into the cone that will evenly distribute the seed across eight six-inch rows over a distance of 25 ft. The red boxes on the back are for 18-46-0 (DAP). We apply 50 lbs of DAP in furrow at all locations. Photo courtesy Woods County Educator Greg Highfill

Robert Calhoun and Matt Knori sow the 2013/2014 wheat variety test plots at Alva, OK. Robert is dropping a 60 gram envelope of seed into the cone that will evenly distribute the seed across eight six-inch rows over a distance of 25 ft.
The red boxes on the back are for 18-46-0 (DAP). We apply 50 lbs of DAP in furrow at all locations.
Photo courtesy Woods County Educator Greg Highfill

 

 

2013 Wheat variety performance test results posted

All Oklahoma wheat variety test sites are now harvested and the results are posted at www.wheat.okstate.edu. I have posted a brief summary of the 2013 crop below. Over the next several weeks, I will be posting additional trial results on this blog along with opinion and analysis of results.

 

2013 WHEAT CROP OVERVIEW

At the time of writing this report, 2013 Oklahoma wheat production is estimated to be approximately 114 million bushels, which is roughly 26% less than 2012 production (Table 1).  The production decrease was due to the combination of lower yields and fewer harvested acres. Given the challenges faced in the 2012-2013 wheat production year, however, most would consider the average yield and total production to be much better than expected.

 

Table 1. Oklahoma wheat production for 2012 and 2013 as estimated by OK NASS, June 2013
 

2012

2013

Harvested Acres

4.3 million

3.8 million

Yield (bu/ac)

36

30

Total bushels

154.8 million

114 million

 

We have had several dry starts for wheat planting in Oklahoma, but the fall of 2012 might go down as the driest of the dry. A few timely rains in late August and early September allowed early and mid-September sown wheat to emerge and get a rapid start on forage production. This was the last substantial rain that most of western Oklahoma received until early 2013. As a result, much of our October-sown crop remained partially emerged in dry soil until after the first of the year.

 

Wheat that had emerged in September had consumed available water by early November and turned brown by December. Many fields were assumed dead, as there was no green tissue remaining above the soil surface (e.g. Marshall Dual-Purpose trial). This left little to no grazing potential for many dual-purpose wheat producers. Our Stillwater forage trial, for example, had less than 500 lb/ac (estimated) of available forage in early December, which is our normal forage measurement timing.

 

Rain was not plentiful in early 2013, but there was enough to allow the wheat crop to rebound. Wheat seed that had been lying in the soil germinated and early-emerging fields that had turned brown from drought were resuscitated and brought back to life. Wheat in southwestern OK and the Panhandle remained on life support throughout the season, surviving but never really thriving. Given these extreme circumstances, the grain yield at our Chattanooga, Altus, and Hooker sites are nothing short of amazing. Although wheat finally emerged at our Alva, Balko, Buffalo, Cherokee, Gage, Keyes, and Lamont sites, the stands were far too variable for use in comparing the yield potential of wheat varieties.

 

Drought was not the only weather-related issue Oklahoma wheat producers dealt with in 2013. There were multiple rounds of freeze events in late March and early April. Wheat in southwest Oklahoma and the Panhandle was affected by different freeze events but both sustained 30 to 80% tiller loss and were largely written off in the weeks following the freezes. Outside of far southwestern OK, cooler than normal conditions and some replenishment of soil moisture allowed regeneration of tillers. This, along with extended grainfill duration, allowed many wheat fields to recover and produce greater than expected grain yields (e.g. Apache variety trial). The cooler than normal spring temperatures were beneficial for wheat grainfill, but also delayed harvest by about one month as compared to 2012 and about two weeks as compared to the long term average.

 

It was a fairly quiet year regarding foliar disease. Pockets of the state suffered from heavy powdery mildew infestation in March and April, and some wheat producers chose to split-apply fungicides to combat this disease. There were also areas affected by glume blotch, tan spot, and septoria, but there was not much leaf or stripe rust present.

 

Yellow and purple leaves were tell tale signs that a late spring flush of aphids had transmitted barley yellow dwarf virus to several Oklahoma wheat fields. Armyworms were present late in the season, but generally did not reach threshold levels prior to maturity and few fields were sprayed. Winter grain mites took advantage of slow-growing, drought-stressed wheat and were a frequently reported problem in southwest OK, but the wheat curl mite takes top billing among mite pests in 2013. The wheat curl mite transmits wheat streak mosaic and high plains viruses. These two diseases are fairly common in the Panhandle but do not typically affect wheat in central OK. In 2013 fields as far east as Kingfisher tested positive for wheat streak mosaic and several central OK fields were affected. Growers affected by wheat streak mosaic should take care to ensure that any volunteer wheat or corn is dead at least two weeks prior to planting to reduce the risk of this disease in 2013-2014.

 

Wheat better than expected at Chattanooga, Kingfisher, and Chickasha

Chattanooga, Kingfisher, and Chickasha wheat variety trial results are posted at www.wheat.okstate.edu.  Grain yields at Chattanooga ranged from 12 to 36 bushels per acre. It is truly amazing that wheat somehow managed to produce these yields this in the presence of severe drought and three major freezes. Kingfisher wheat grain yields ranged from 32 to 47 bushels per acre and were more or less on par with expectations. This site had less than ideal moisture conditions, but adequate moisture to keep the wheat from turning brown as it did in many locations.

The Chickasha wheat variety trial had some problems. A late March freeze killed up to 58% of viable tillers in some varieties and lodging at harvest was moderate to severe. While leaf rust and stripe rust were not major factors, we did have a variety of leaf spotting diseases (e.g. tan spot, septoria, glum blotch) and severe, widespread bacterial blight/black chaff throughout the plot. In spite of these challenges, average yield at this site was 69 bushels per acre with yields ranging from 50 to 83 bushels per acre. While these yields are outstanding given the challenges of the year, they are not the best at the Chickasha research station. Approximately 200 feet from the variety trial was a growth regulator study planted to Iba that produced 98 to 102 bushels per acre. I have this same trial at two additional locations and will summarize results later in the year.

Both small plot combines running at Chickasha

Both small plot combines running at Chickasha

Altus wheat variety trial results

It was a rough year to farm wheat in Altus, OK. Our plots were sown into extremely dry soil on October 8, 2012 and received a total of 1.08 inches of rain by December 31. Total rainfall for the entire season was only 7.9 inches. Under these conditions it is amazing that wheat survived, but we somehow entered March with approximately 30 bu/ac yield potential. Some production fields in the area had 50 bu/ac potential and needed nothing more than a few rains to maintain this yield potential. The rains never came and Mother Nature dealt an additional card from the bottom of the deck with major freeze events in late March, late April, and early May.

Altus wheat variety trial results are posted at www.wheat.okstate.edu. Top varieties this year were Doublestop CL Plus (25 bu/ac), WB-Grainfield (22bu/ac), and the OSU experimental lines OK08328 (23 bu/ac) and OK09125 (22 bu/ac). Eleven out of 39 varieties made less than 10 bu/ac, and it is hard to say if drought or freeze had the larger effect on wheat yield. Based on the maturity rating of the top yielding varieties (ie late maturing) one could make the argument that freeze had the larger effect, but some relatively early and medium maturing varieties performed relatively well in the presence of the freeze (e.g. Duster and OK Bullet). The interactions are complicated and not easily explained.

Additional variety trial results will be posted as locations are harvested. To keep up with the latest results, follow me on Twitter @OSU_smallgrains