2016

Posted on February 26, 2016 by Amanda De Oliveira Silva

First hollow stem measured in wheat sown 09/15/2015 at Stillwater, OK. Varieties with no hollow stem value reached first hollow stem on a previous measurement date
Variety	cm of hollow stem 02/26/16
Endurance	0.9
OK Rising	1.3
Billings
Ruby Lee	1.3
Duster	1.2
Gallagher
Iba
Bentley
Doublestop CL Plus	1.3
NF 101
WB-Cedar
WB4458
WB-Grainfield	1.6
Winterhawk
WB4515
WB4721
WB4303
SY Monument	0.9
SY Flint
SY Llano
SY Drifter
SY Wolf	1.1
SY Razor
SY Grit
Everest
1863
KanMark	1.4
Oakley CL	1.3
Larry	0.8
Zenda
Tatanka	1.0
Joe	0.7
LCS Pistol	0.9
LCS Wizard	1.2
LCS Mint	0.9
LCS Chrome	1.0
T158	1.0
Long Branch	1.1
TAM 112	1.2
TAM 204	1.3
TAM 114	1.3
AG Robust	1.6
Byrd	1.2
Brawl CL Plus	0.6
Avery	0.7
OK1059060-3	1.3
OK10126	0.7
OK11D25056	0.8
OK12621	0.8
OK10728W	0.8
OK12716R/W	0.6
OK11231	0.8
OK09915C-1	0.6
OK12912C	1.0
OK12DP22002-042	1.2
OK118036R/W
Average	1.0

First hollow stem update 02/23/2016

Posted on February 23, 2016 by Amanda De Oliveira Silva

First hollow stem is the optimal time to remove cattle from wheat pasture (full explanation). We measure first hollow in our September-sown wheat forage plots at Stillwater each year, and normally have approximately 50% of varieties at or past first hollow stem by March 1st. I have posted first hollow stem measurements from these plots in a table at the end of this blog. As of Monday the varieties, Billings, Gallagher, Iba, Bentley, NF101, WB-Cedar, WB4458, Winterhawk, WB4515, WB4721, WB4303, SY Flint, Sy Llano, SY Drifter, SY Razor, SY Grit, Everest, and Zenda were all at or past first hollow stem at Stillwater. Please note that WB4515 was incorrectly labeled as WB4455 in the past couple of posts. Also note that experimental line OK0728W has been released as Stardust hard white winter wheat. We will take another set of measurements at the end of this week and report the results on this blog.

First hollow stem measured in wheat sown 09/15/2015 at Stillwater, OK.
Variety	cm of hollow stem 02/22/2016
Endurance	0.8
OK Rising	1.3
Billings	2.1
Ruby Lee	1.2
Duster	1.1
Gallagher	2.0
Iba	1.9
Bentley	1.8
Doublestop CL Plus	1.2
NF 101	2.5
WB-Cedar	1.5
WB4458	1.9
WB-Grainfield	1.3
Winterhawk	1.5
WB4515	1.6
WB4721	1.5
WB4303	2.1
SY Monument	0.8
SY Flint	1.5
SY Llano	2.8
SY Drifter	1.5
SY Wolf	1.0
SY Razor	2.9
SY Grit	1.7
Everest	1.5
1863	2.1
KanMark	1.4
Oakley CL	1.0
Larry	0.7
Zenda	1.6
Tatanka	0.9
Joe	0.7
LCS Pistol	0.8
LCS Wizard	1.2
LCS Mint	0.8
LCS Chrome	0.8
T158	0.8
Long Branch	1.0
TAM 112	0.9
TAM 204	1.2
TAM 114	0.7
AG Robust	1.0
Byrd	0.6
Brawl CL Plus	0.6
Avery	0.5
OK1059060-3	1.3
OK10126	0.6
OK11D25056	0.6
OK12621	0.7
Stardust	0.7
OK12716R/W	0.5
OK11231	0.6
OK09915C-1	0.5
OK12912C	0.9
OK12DP22002-042	0.9
OK118036R/W	2.0
Average	1.2

First hollow stem update 02/19/2016

Posted on February 19, 2016 by Amanda De Oliveira Silva

First hollow stem is the optimal time to remove cattle from wheat pasture (full explanation). We measure first hollow in our September-sown wheat forage plots at Stillwater each year, and normally have approximately 50% of varieties at or past first hollow stem by March 1st. I have posted first hollow stem measurements from these plots in a table at the end of this blog. No varieties are currently at first hollow stem at Stillwater, but given the warm conditions and the estimates from the first hollow stem advisor on the Mesonet, I anticipate we will have some varieties past first hollow stem by next week. Note that while no varieties are currently at first hollow stem, the overall average first hollow stem measurement increased as compared to 02/16/15. Dillon Butchee reported early sown Gallagher in the Altus area was at first hollow stem.

Keep in mind that the numbers reported from Stillwater are likely behind those being observed in southern Oklahoma and ahead of those observed in northern Oklahoma. The First Hollow Stem Advisor on the Oklahoma Mesonet indicates that early varieties in southern Oklahoma are likely past first hollow stem and that early varieties in central Oklahoma will reach this point within a week. Jim Johnson with the Noble Foundation reported that the estimates on the first hollow stem advisor were matching closely with his observations in the field around the Ardmore area. My advice is to start looking for a home for cattle on wheat pasture.

First hollow stem measured in wheat sown 09/15/2015 at Stillwater, OK.
Variety	cm of hollow stem 02/19/16
Endurance	0.6
OK Rising	0.5
Billings	1.3
Ruby Lee	1.2
Duster	1.1
Gallagher	1.4
Iba	1.1
Bentley	0.7
Doublestop CL Plus	0.6
NF 101	1.1
WB-Cedar	0.7
WB4458	0.8
WB-Grainfield	1.0
Winterhawk	0.9
WB4455	0.6
WB4721	1.3
WB4303	1.2
SY Monument	0.6
SY Flint	1.3
SY Llano	1.0
SY Drifter	0.8
SY Wolf	0.4
SY Razor	1.4
SY Grit	1.3
Everest	0.6
1863	0.9
KanMark	0.7
Oakley CL	0.7
Larry	0.4
Zenda	1.1
Tatanka	0.4
Joe	0.6
LCS Pistol	0.6
LCS Wizard	0.6
LCS Mint	0.7
LCS Chrome	0.6
T158	0.7
Long Branch	0.9
TAM 112	0.7
TAM 204	0.6
TAM 114	0.4
AG Robust	0.7
Byrd	0.6
Brawl CL Plus	0.5
Avery	0.4
OK1059060-3	0.5
OK10126	0.3
OK11D25056	0.5
OK12621	0.4
OK10728W	0.6
OK12716R/W	0.4
OK11231	0.4
OK09915C-1	0.4
OK12912C	0.7
OK12DP22002-042	0.8
OK118036R/W	1.1
Average	0.7

First hollow stem update 02/16/2016

Posted on February 16, 2016 by Amanda De Oliveira Silva

First hollow stem is the optimal time to remove cattle from wheat pasture (full explanation). We measure first hollow in our September-sown wheat forage plots at Stillwater each year, and normally have approximately 50% of varieties at or past first hollow stem by March 1st. I have posted first hollow stem measurements from these plots in a table at the end of this blog. No varieties are currently at first hollow stem at Stillwater, but given the warm conditions and the estimates from the first hollow stem advisor on the Mesonet, I anticipate we will have some varieties past first hollow stem by the end of the week. We will take another set of measurements at the end of this week and report the results on this blog.

Current first hollow stem estimates for early maturity wheat varieties

One week projection of first hollow stem for early maturity wheat varieties

Two week projection of first hollow stem for early maturity wheat varieties

First hollow stem measured in wheat sown 09/15/2015 at Stillwater, OK.
Variety	cm of hollow stem 02/15/16
Endurance	0.0
OK Rising	0.1
Billings	0.4
Ruby Lee	0.3
Duster	0.1
Gallagher	0.7
Iba	0.8
Bentley	0.6
Doublestop CL Plus	0.3
NF 101	0.4
WB-Cedar	0.4
WB4458	0.7
WB-Grainfield	0.0
Winterhawk	0.0
WB4455	0.1
WB4721	0.3
WB4303	1.2
SY Monument	0.0
SY Flint	0.7
SY Llano	1.0
SY Drifter	0.1
SY Wolf	0.2
SY Razor	1.4
SY Grit	0.4
Everest	0.2
1863	0.8
KanMark	0.0
Oakley CL	0.2
Larry	0.0
Zenda	0.8
Tatanka	0.0
Joe	0.0
LCS Pistol	0.0
LCS Wizard	0.2
LCS Mint	0.1
LCS Chrome	0.1
T158	0.3
Long Branch	0.2
TAM 112	0.3
TAM 204	0.4
TAM 114	0.0
AG Robust	0.2
Byrd	0.1
Brawl CL Plus	0.1
Avery	0.2
OK1059060-3	0.0
OK10126	0.1
OK11D25056	0.1
OK12621	0.0
OK10728W	0.2
OK12716R/W	0.4
OK11231	0.0
OK09915C-1	0.0
OK12912C	0.4
OK12DP22002-042	0.1
OK118036R/W	0.3
Average	0.3

First hollow stem nearing

Posted on February 16, 2016 by Amanda De Oliveira Silva

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’

Wheat disease update – 10 February 2016

Posted on February 10, 2016 by Amanda De Oliveira Silva

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

Since my last report, I don’t believe a lot has changed with the disease situation. Similar to what I indicated in mid-December, I have continued to find small pustules of powdery mildew and a few scattered leaf rust pustules in rank wheat around Stillwater. The temperature and weather has been such that these two foliar diseases (powdery mildew and leaf rust) have been able to persist but have not increased in the wheat around Stillwater. This seems to be the case for southwestern and south central OK as well.

Gary Strickland (Extn Educator & SWREC Dry-land Cropping Systems Specialist; Jackson/Greer Cnty in SW OK) indicated wheat in SW OK is quite a ways behind the rest of the state and mostly is just now establishing a solid root system. He had sent us a sample last week in which he expected a root rot to be involved, but we were not able to confirm any root rot pathogens. Gary also indicated that he has confirmed Hessian fly at damaging levels in at least a few fields in Jackson Cnty. He is going out in the next few days to scout additional fields. Aaron Henson (Extn Educator; Tillman Cnty in southern OK) indicated wheat in his area varies from quite small to well-established with the majority of the wheat not yet jointing. He is aware of the earlier reports of scattered stripe rust showing in south-central OK, but has not heard anything to indicate increase in incidence or severity. For additional information regarding early season foliar wheat diseases and possible control with an early fungicide application please see:

E-Pest Alert (Dec 18, 2015; vol. 14, no. 46) at http://entoplp.okstate.edu/pddl/pdidl
A fact sheet discussing split application of fungicides at www.wheat.okstate.edu
A February 9th post on this blog

Also around Stillwater, I am beginning to see symptoms indicative of wheat soil-borne mosaic/wheat spindle streak mosaic in areas such as my WSBM/WSSM screening nursery. At this point, it is somewhat difficult to differentiate between symptoms of WSBM/WSSM and discoloration resulting from cold. The photo below shows the contrast between a variety susceptible to WSBM/WSSM and a resistant variety, but was taken about 2-3 weeks later than today. Thus, over the next month as temperature rises and wheat greens up, symptoms will become more striking. However, nearly 100% of varieties planted across Oklahoma are resistant to both these viruses, so this disease complex has not caused a problem to wheat in Oklahoma (or other states) for many years. For more information on the WSBM/WSSM complex, go to: https://www.youtube.com/user/OSUWheat/videos and watch the video on “Wheat Soilborne Mosaic Virus and Wheat Spindle Streak Mosaic Virus.”

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

Powdery mildew

Wheat stripe rust

Wheat leaf rust

Mature Hessian fly larvae are brown in color and often referred to as flaxseed. Tillers with larvae will not recover and will eventually die and slough off.

Is this the year for split fungicide application?

Posted on February 9, 2016 by Amanda De Oliveira Silva

The stripe rust epidemic of 2015 is still fresh on the minds of many wheat farmers. Reports of active stripe rust on wheat in southern Oklahoma has producers now wondering if we are in for a repeat in 2016. While it is too early to tell if environmental conditions will favor a stripe rust outbreak in 2016, having active rust on wheat in the area satisfies at least one of the requirements for an epidemic. Most Oklahoma wheat producers will still be best advised to monitor the situation and make the fungicide decision based on yield potential and likelihood of infection when the flag leaf is emerging. Those with fields already showing heavy infection of foliar disease, however, might also benefit from a two-pass fungicide system. A few talking points and items to consider for those considering a two-pass system are posted below. A fact sheet on the topic of split application of fungicides can be found at www.wheat.okstate.edu

When to apply – The first pass in a two-pass fungicide system should be applied just after jointing. Please note that this is well after topdress nitrogen should be applied. For this and other reasons (see Dr. Arnall’s blog), tank mixing fungicides with nitrogen is generally not a good practice. Remember that the purpose of the early fungicide application is to keep disease in check until you come back with a flag leaf application in April. Going too early can result in too large of a gap between applications and enough time for disease to re-establish. Going too late can reduce the return on investment. Timing is everything with fungicides.

How much to apply – Back in the day, the discussion around split fungicide application centered on half rates for the first application. This recommendation was because of cost savings rather than disease management. The availability of low-cost, generic fungicides, though, has changed our philosophy, and a full rate of a low cost fungicide is the standard for split applications.

Which product to choose – Product choice is at the discretion of the consumer. If you are considering how to best spend your season-long fungicide budget, however, I would strongly recommend saving your “best” and perhaps most expensive product for the flag leaf application.

Watch season-long restrictions – As always, please read labels carefully and make note of season-long application restrictions. You don’t want an early fungicide application to remove the ability to apply your preferred product at flag leaf.

Wheat stripe rust

This overhead shot of the 2015 Chickasha intensive and standard wheat variety trials illustrates the severity of stripe rust in the region. The intensively managed trials on the left was treated with a fungicide just prior to heading. The standard trial on the right has the exact same varieties but no fungicide. The “middle” replication between the two studies is a border of Ruby Lee that is 1/2 treated 1/2 non treated.

Spring-planted oat for forage

Posted on February 9, 2016 by Amanda De Oliveira Silva

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

Spring oat can provide an alternate hay or forage source in the spring

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

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

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

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

WORLD OF WHEAT

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Monthly Archives: February 2016