First Hollow Stem Update – 2/15/2022

Amanda de Oliveira Silva, Small Grains Extension Specialist

First hollow stem (FHS) is the optimal time to remove cattle from wheat pasture. This occurs when there is 1.5 cm (5/8”, or the diameter of a dime) of hollow stem below the developing grain head (see full explanation). The latest FHS results from OSU forage trials in Stillwater (Table 1) and Chickasha (Table 2) are listed below. For an additional resource, see the Mesonet First Hollow Stem Advisor.

We use an accelerated growth system to report the earliest onset of FHS stage. Trials are seeded early to simulate a grazed system, but the forage is not removed. Varieties reported here with the earliest FHS date should be the first to monitor in commercial fields. In practice, wheat that is grazed will likely reach FHS stage later than reported here, and differences between varieties will likely moderate.

Values can fluctuate from one sampling to another due to environmental variation associated with, among other factors, the winter storm on February 2-4. Additionally, varieties differed widely in their FHS response following this cold period.

Table 1. First hollow stem (FHS) results for each variety collected at Stillwater. Plots were planted on 09/27/21 but not grazed or clipped. The threshold target for FHS is 1.5 cm (5/8″ or the diameter of a dime). The value of hollow stem for each variety represents the average of ten measurements. Varieties exceeding the threshold are highlighted in red.

Table 2. First hollow stem (FHS) results for each variety collected at Chickasha. Plots were planted on 09/28/21 but not grazed or clipped. The threshold target for FHS is 1.5 cm (5/8″ or the diameter of a dime). The value of hollow stem for each variety represents the average of ten measurements. Varieties exceeding the threshold are highlighted in red.

  • Additional resources available:

First Hollow Stem Update – 2/10/2022

Amanda de Oliveira Silva, Small Grains Extension Specialist

First hollow stem (FHS) is the optimal time to remove cattle from wheat pasture. This occurs when there is 1.5 cm (5/8”, or the diameter of a dime) of hollow stem below the developing grain head (see full explanation). The latest FHS results from OSU forage trials in Stillwater(Table 1) and Chickasha (Table 2) are listed below. For an additional resource, see the Mesonet First Hollow Stem Advisor.

We use an accelerated growth system to report the earliest onset of FHS stage. Trials are seeded early to simulate a grazed system, but the forage is not removed. Varieties reported here with the earliest FHS date should be the first to monitor in commercial fields. In practice, wheat that is grazed will likely reach FHS stage later than reported here, and differences between varieties will likely moderate.

Table 1. First hollow stem (FHS) results for each variety collected at Stillwater. Plots were planted on 09/27/21 but not grazed or clipped. The threshold target for FHS is 1.5 cm (5/8″ or the diameter of a dime). The value of hollow stem for each variety represents the average of ten measurements. Varieties exceeding the threshold are highlighted in red.

Table 2. First hollow stem (FHS) results for each variety collected at Chickasha. Plots were planted on 09/28/21 but not grazed or clipped. The threshold target for FHS is 1.5 cm (5/8″ or the diameter of a dime). The value of hollow stem for each variety represents the average of ten measurements. Varieties exceeding the threshold are highlighted in red.

  • Additional resources available:

Estimating the optimal time to remove cattle from wheat pasture (if you still have pasture to graze…) – First Hollow Stem Update

Amanda de Oliveira Silva, Small Grains Extension Specialist

The wheat growing season up to this point has been extremely tough, to say the least. The forage situation has been a kick-in-the-knees. It was challenging to get a stand established and wheat pasture with limited rainfall since planting. By January 30, most of Oklahoma had not seen any significant precipitation for more than 90 days (Figure 1). Last week’s winter storm helped improve conditions in some areas, but western OK continues to be dry (Figure 2). As a result, many producers have already grazed as much as possible and removed their cattle, or they have not even had the chance to graze. For the few producers who still have pasture to graze, leaving some leaf tissue after grazing will be important for having any chance of a decent grain crop. Ideally, there should be a minimum of 60% canopy coverage (measured from the Canopeo app) left to allow the crop to recover from grazing (PSS-2170).

Figure 1. Consecutive days with less than 0.25 inches of rainfall on January 30, 2022.
Figure 2. Consecutive days with less than 0.25 inches of rainfall after the winter storm (top figure) and plant available water in the soil (bottom figure) on February 6, 2022.

The first hollow stem stage (FHS) indicates the beginning of stem elongation, or just before the jointing stage. It is a good indicator for when producers should remove cattle from wheat pasture. This occurs when there is 1.5 cm (5/8”, or the diameter of a dime) of stem below the developing grain head (see full explanation). This is the optimal period because it gives enough time for the crop to recover from grazing and rebuild the canopy. Also, the added cattle weight gains associated with grazing past the FHS are not enough to offset the value of the potential reduced grain yield (1-5% every day past FHS). The wheat variety, severity of grazing, time when cattle are removed, and weather conditions after cattle removal determine how much grain yield potential might be reduced.

The Mesonet First Hollow Stem Advisor was developed by researchers at Oklahoma State University to help predict when FHS is nearing. This is an online tool available on the Mesonet website. This tool uses soil temperature data to show the current probability of FHS occurrence and 1-week and 2-week projections. With this tool, producers can select their variety from a list of varieties that separates them into three FHS categories: early, middle, and late. Then, maps can be generated to provide the probability of FHS based on current conditions and the 1- and 2-week projections. Charts and tables can also be generated for individual Mesonet sites. Created maps have a color scheme to represent the probability of FHS occurrence. When using this tool, it is recommended to start scouting for FHS from a non-grazed part of the field once the 5% probability is reached (green color). Because stem elongation will begin moving quickly as the air temperature rises, starting your scouting at the 5% level will help give you the time it takes for making the preparations for cattle removal by the time FHS occurs. Methods on how to scout for FHS are listed at the end of this post. For producers who do not scout, it is recommended to remove cattle when the 50% probability level is reached. A 50% probability level indicates that over an evaluated period (e.g., 10 years), FHS would have occurred by that date in 50% of those years (e.g., 5 years). The same interpretation is used for other probability levels.

To give an example of what the tool provides and show some of the FHS conditions around Oklahoma, I have generated some statewide maps below. For producers along the southern Oklahoma border who planted an “early” wheat variety (e.g., Gallagher), now would be the time to go out and start scouting for FHS (Figure 3).

Figure 3. Current FHS probabilities for “early” wheat varieties.

Looking at the 1-week projection for early maturing FHS varieties, you can see how the probabilities have increased, and areas further north should begin scouting (Figure 4).

Figure 4. One-week FHS projection (i.e., through February 14) for “early” wheat varieties.

For producers who planted late-maturing FHS varieties (e.g., LCS Chrome), the 1-week projections indicate producers across much of the state still have a little bit of time before beginning to scout (Figure 5).

Figure 5. One-week FHS projections (i.e., through February 14) for “late” (bottom) wheat varieties.

Remember that this tool should be used as a proxy to begin scouting for FHS. The best estimate of FHS is still to split stems from plants in each field to determine where they are developmentally. Another word of caution I want to mention when using the tool for this year especially is to consider when you were finally able to get stand establishment. If this did not occur until the end of September to the beginning of October, this tool may be a little ahead of where your plants are developmentally. In this case, the tool can still give you the cue to start scouting. Checking for FHS in each field will let you know if you do have some grazing time left.

Methods for scouting for FHS:

  • Check for FHS in a non-grazed area of the same variety and planting date. Variety can affect FHS date 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 the developing grain head may still be below the soil surface at this stage.
  • If there is 1.5 cm (~5/8″) of hollow stem present, it is time to remove cattle. 1.5 cm is about the same as the diameter of a dime (see picture below).
  • More detailed information on FHS can be found at wheat.okstate.edu under ‘Wheat Management’ then ‘Grazing’ or by clicking here.
The first hollow stem growth stage is reached when there is 1.5 cm of hollow stem (about the diameter of a dime) below the grain head.

Similar to previous years, we will monitor FHS occurrence in our wheat plots at Stillwater and Chickasha and report the findings on this blog. Remember that we use an accelerated growth system to report the earliest onset of the FHS stage. Trials are seeded early to simulate a grazed system, but the forage is not removed. Varieties reported here with the earliest FHS date should be the first to monitor in commercial fields. In practice, wheat that is grazed will likely reach FHS stage later than reported here, and differences between varieties will likely moderate.

The latest FHS results for each variety planted in our forage trial at Stillwater are listed below (Table 1). A few varieties were near FHS (values at or above 1.5 cm) before the winter storm last week, and values are likely to move quickly with warmer conditions in Oklahoma.

Table 1. First hollow stem (FHS) results for each variety collected at Stillwater. Plots were planted on 09/27/21 but not grazed or clipped. The threshold target for FHS is 1.5 cm (5/8″ or the diameter of a dime). The value of hollow stem for each variety represents the average of ten measurements. Varieties exceeding the threshold are highlighted in red.

Freeze damage update

Amanda de Oliveira Silva, Small Grains Extension Specialist

It has been almost one month since the freeze event on April 21, and we are now obtaining a better picture of potential freeze damage on wheat fields across Oklahoma. As I have indicated, the extent of the freeze damage will depend on several factors, including the growth stage of the plants, how low the temperature will get, and how long it stays at those cold temperatures. Wheat growth stage ranged from flag leaf emergence to heads starting to or fully emerged when the freeze occurred, and number of hours and temperature varied across the state (Figure 1).

Figure 1. Hour below freezing two days after the freeze event.

Traveling around the state for plot tours these past weeks, I have seen and heard about damage ranging from minimal to quite severe. Some fields seem to be fine with only scattered damaged heads and the grain appears to be filling as expected. Other fields however, show much more significant damage with discolored and sterile heads.

At the plot tour at Chickasha on April 30, there was a mix of freeze and hail damage with several abnormally growing heads (due to head trapping). Anthers seemed to be fine at that point (Figure 2).

Figure 2. Abnormally growing wheat heads at the Chickasha variety trial on April 30.

On May 7, I checked some wheat fields around Sentinel with Gary Strickland (Jackson County Extension Educator and SW Regional Agronomist) and we observed almost no freeze damage with a few heads in the field showing a pale color and partial sterility (Figure 3). I have observed this symptom commonly in fields I have visited, and many producers have described this to me as well.  Although common, it typically has been found at a low incidence.

Figure 3. Freeze damaged heads with partial sterility and pale color near Sentinel, OK on May 7.

We observed a few spots with freeze damage while at Alva on May 12, especially in low spots of the field and on the tops of terraces. Again, relatively few spots in the field showed damage. The wheat was looking good at Alva, but really needing a rain (Figure 4).

Figure 4. Freeze damage on wheat in low spots of the field at Alva, May 12.

The most severe freeze damage that I have seen so far was yesterday near Morris in eastern OK. The heads were green but there was no grain present (i.e. sterile). Damaged heads had glumes with a chocolate discoloration, which is similar to the discoloration caused by the bacterial disease called black chaff. In some cases, Dr. Hunger and I felt these discolored heads were the result of this bacterial disease but that the majority of the heads showing these symptoms were the result of freeze damage (Figure 5).

Figure 5. Freeze damaged heads without grains inside and showing a chocolate color on the outside (top photos). Heads showing no freeze damage and black chaff bacterial disease (bottom photos).

At the plot tour at El Reno today, we also observed a few varieties with pale colored and “empty” heads due to the freeze (Figure 6). We observed more freeze damage on wheat that was planted earlier and grazed as compared to the grain-only (ungrazed) wheat in that same field. Another noteworthy item is related to my earlier observation that the February freeze hurt some of the varieties in the dual-purpose plots by severely reducing tillering that would cause a loss of stand. That observation in those varieties was confirmed as the stand loss was quite evident today.

Figure 6. Wheat at El Reno. Same variety under grain-only (left) and dual-purpose (right) systems.

In conclusion, the freeze damage I am seeing is variable within and across fields, but overall I would say is minimal in most of the state. However, continue to keep scouting as it will now be easier to identify freeze damage.

Please let me know what you are seeing out there! My email is silvaa@okstate.edu.

Also, contact your County Extension office for more information.

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’
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