About Me

osuwheat

osuwheat

Since 2004 I have served as the Small Grains Extension Specialist at Oklahoma State University. I work to improve the profitability and sustainability of small grains production in the southern Great Plains through improved management and variety selection. Most of my work focuses on dual-purpose and grain-only wheat production.

View Full Profile →

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 787 other followers

Freeze injury update 15 April 2014

I have posted a few images from the Oklahoma Mesonet below. Most of Oklahoma spent at least four hours below freezing last night and some areas spent an extended period of time below 28F. While temperatures in the wheat canopy might have remained slightly higher than reported air temperatures, they were still probably low enough to result in significant injury to wheat.

Over the next few days growers will need to inspect fields closely to determine the extent of injury. Symptoms may start to appear later this week and will likely be clearly identifiable by early next week. Healthy wheat heads will remain turgid with a green color. Damaged wheat heads will be bleached, yellow, or brown and will easily break when pushed against. I anticipate that we will not have any partial “blanking” of wheat heads and that most wheat heads will either be okay or a complete loss.

What about new tillers? New tillers might emerge, but it is already April 15. In addition we have very dry soil conditions. For these reasons I am doubtful that newly emerging tillers will have much yield potential in areas south of I-40. IF (and that is a big if) weather conditions remain favorable, late emerging tillers in northern Oklahoma might still have a shot at producing grain.

I will survey some fields in a few days and report back with my findings. If you are interested in receiving weather maps and updates such as the ones posted below, subscribe to the OCS Mesonet Ticker by emailing ticker@mesonet.org

Hours below freezing on April 15, 2014

Hours below freezing on April 15, 2014

Hours below 28 F on April 15, 2014

Hours below 28 F on April 15, 2014

Hours below 24F on April 15, 2014

Hours below 24F on April 15, 2014

 

Potential for freeze injury

Temperatures are predicted to drop well below freezing tonight (14 April 2014), and there is high potential for freeze injury to Oklahoma wheat. I have posted an excerpt from K-State Extension Publication C-646 Spring Freeze Injury to Kansas Wheat along with a map which provides some rule of thumb temperature thresholds for the current Oklahoma wheat crop. Keep in mind these temperature thresholds are not exact, and temperatures closer to the soil surface might be higher than those reported by weather stations one meter above the soil surface, especially if moisture is present. Wheat in Oklahoma ranges from just past jointing to late boot and if forecasts are correct we will drop below the threshold temperatures where injury might be observed. The extent of injury will depend on how cold we get and how long we stay there. We can lose a few main tillers at this stage and still recover. Given our limited moisture and limited time prior to harvest, though, it is not likely that we will recover from a complete loss of tillers as we have after some March freezes in the past.

Excerpt from KSTATE publication C-646 Spring Freeze Injury to Kansas Wheat

Excerpt from KSTATE publication C-646 Spring Freeze Injury to Kansas Wheat

 

Approximate temperature thresholds for freeze injury to Oklahoma wheat on 04/14/2014

Approximate temperature thresholds for freeze injury to Oklahoma wheat on 04/14/2014

Freeze injury is not clearly identifiable until 7 – 10 days after the freeze event. So, the best advice for a wheat farmer after a freeze event is to find something else to do for a week or two and then check your crop. I have provided some pictures below with typical injury symptoms and rules of thumb regarding the extent of the injury. Fields should be checked at several random locations by splitting 10 – 20 stems at each location and looking for injury. Don’t focus solely on the large stems. Split a random sampling and determine the percent damage. A good reference for evaluating freeze injury to wheat is K-State Extension Publication C-646 Spring Freeze Injury to Kansas Wheat (access online by clicking here).

This is a healthy wheat head at approximately growth stage 6 - 7. Note the light green color and healthy, turgid appearance.

This is a healthy wheat head at approximately growth stage 6 – 7. Note the light green color and healthy, turgid appearance.

Freeze injury just after jointing. Note the pale, milky color of the head.

Freeze injury just after jointing. Note the pale, milky color of the head. Freeze injury to wheat heads at this growth stage is all or none, so this head is a complete loss.

Leaf tip burn from freeze injury will have no impact on final grain yield

Leaf tip burn from freeze injury will have no impact on final grain yield

Yellowing is a common reaction to light freeze injury. Wheat will recover quickly from this injury.

Yellowing is a common reaction to light freeze injury. Wheat will recover quickly from this injury.

Severe freeze injury at or just after jointing can turn the entire plant brown and fields can exude an odor similar to fermenting silage. If conditions are favorable, the plant can produce new tillers (as shown here) and make a partial recovery. It will take a few weeks after a freeze event to determine if the plant will recover from this type of injury

Severe freeze injury at or just after jointing can turn the entire plant brown and fields can exude an odor similar to fermenting silage. If conditions are favorable, the plant can produce new tillers (as shown here) and make a partial recovery. It will take a few weeks after a freeze event to determine if the plant will recover from this type of injury

It is common for sub-lethal freeze injury to result in bent or weak lower nodes. These plants might look fine, but will lodge during grain fill.

It is common for sub-lethal freeze injury to result in bent or weak lower nodes. These plants might look fine, but will lodge during grain fill.

Wheat disease update – 10 April 2014

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

Oklahoma:  Wheat around Stillwater is mostly at GS 7 (2 nodes detectable).  In a few places the flag leaf has emerged but only in one field.  I still have not received reports of significant foliar diseases in Oklahoma, which is not surprising given the dry conditions.  Around Stillwater I have seen some powdery mildew on low foliage in scattered spots.  I and my technician Brian Olson also found tan spot in a no-till field, but only on low foliage and not severe.  The one find of a different disease that is concerning was wheat streak mosaic (WSM) in Dr. Jeff Edward’s variety trial in Kay County near Kildare.  Visiting the trial on April 2nd, yellowing and streaking were present in all varieties but some were much worse than others.  I was not thinking about WSM at the time, but 5 samples I brought back to the lab all tested positive for the virus that causes WSM, so I believe that is what is present.  On a trip today to northern Oklahoma and over to Lahoma in north central Oklahoma, I saw some good and some bad wheat that ranged from GS 6 to GS 7 (or close to it).  However, all the wheat seemed short to me – some not much more than 10-12 inches tall.

Powdery mildew

Powdery mildew

In northwestern Oklahoma, Rick Kochenower (Area Res & Extn Agron Spclt) indicated, “I see a lot of dryland wheat dying but not from disease.”  He said that wheat was just starting to tiller.  In southern/central/southwestern Oklahoma, Mark Gregory (Area Extn Agron Spclt) reported that today he was in wheat towards the eastern side of the district and saw no diseases; also that the wheat furthest along had flag leaves fully extended (GS 9).  Gary Strickland (Extn Educator, Jackson County – southwestern OK) indicated wheat in his area was in the flag leaf stage – anywhere from flag leaf just emerging to fully-emerged.  Drought is the problem; no rust, powdery mildew or other diseases, but brown wheat mites have exploded.

Reports/excerpts of reports from other states:

Texas (southern) Dr. Amir Ibrahim (Prof, Small Grains Breeding & Genetics, Texas A&M Univ) 09-Apr-2014:

Wheat rust conditions at Castroville, TX - Wheat looks very good here and most of it is at the ripening stage. We have been applying a ½ of irrigation per week for the past two weeks. We may put another ½ next week, depending on the conditions. The morning fog at this location is also keeping the rust going.

Wheat stripe rust (P. striiformis)- This week provided an opportunity for taking notes on infection type and severity of wheat stripe rust (P. striiformis). Evidence points to a milder repeat of 2012 virulence that attacked ‘TAM 111’, ‘Garrison’ and other HRW. There is no indication of Yr17 vulnerability, which seemed as a one‐time incident that took place in 2010. Stripe rust is up to 70S on susceptible ‘Patton’.  We don’t expect infection types to be distinguishable next week but ratings for green leaf area duration can be taken. A lot of guessing has to be made, though, as both P. striiformis and P. triticina have been competing for the upper leaf surfaces. The former has started to dry up and newer infections are not likely. This does not overrule establishment farther north of here where conditions are conducive.  ‘Armour’ received a 40 S rating at this site, but ‘Redhawk’ looks very vulnerable with a rating 50S on the flag leaf and homogenous spread across the plot.

Wheat leaf rust (P. triticina): While stripe rust infections are fading, leaf rust (P. triticina) is now moving into the flag leaves of susceptible wheat. I have rated TAM 112 as 15S (FL) today. We have good diversity of races, but the Lr24 virulence is moving faster as evidenced by the rating of 60S on the flag leaves of ‘Jagalene’ as opposed to Lr17Lr39, and Lr41. We plan to come back here on April 21st to take notes on leaf rust, tag plants, and make selections.

Texas  Dr. Ron French (Ast Prof, Extn Plant Pathologist, Texas A&M AgriLife Extn Service) 10-Apr-2014:  I have spent many of the last 14 days traveling the Northern Central part of the state, from Wichita Falls (right along the Oklahoma border) and towards Amarillo (220 miles NW of Wichita Falls), and From Amarillo down to the Plainview area (70 miles south) and the Lubbock area (120 miles south of Amarillo). I have not seen any rust at all in commercial fields. Visual observation but also sampled just in case rusts were latent and not quite rupturing the epidermal tissue. No reports of there being any rusts from consultants as well.

From what I have gathered from consultants, there is/has been stripe rust as far north as Waxahachie, TX (Ellis County), 30 miles south of Dallas. Other locations with stripe rust are around Elgin, TX (Bastrop and Travis Counties, approximately 25 miles East of Austin, TX) and Taylor, TX (Williamson Co, approximately 25 miles south of Austin and approximately 75 miles West of College Station).

As far as leaf rust is concerned, these and other locations in that area have also had leaf rust, and in varieties such as Greer, Cedar, and Coronado.  Low levels but enough to warrant sprays as much of that crop is fully headed. In some locations, 7-10 before getting into the milk stage for Cedar.  I have also been told that Fannin had low levels of rust, something out of the usual.  I need to confirm which rust it is (leaf or stripe).

We are a bit behind other years where we have seen leaf rust by late March/early April as far north as Wichita Falls (a few miles from the Oklahoma border) and early April for stripe rust, North and Northeast of Dallas and close to the Oklahoma border.

With temperatures expected to be in the high 80s and low 90s Fahrenheit in the Texas High Plains sometime this weekend but lower next week but with little to no rain, disease pressure is still not there (humidity-wise) although common heavy winds could bring inoculum our way.

Texas (northern – blacklands area north of Dallas)  Jim Swart (IPM, Texas A&M AgriLife Extension 31-Mar-2014:  Wheat is rapidly recovering from the hard freeze we received in early March.  Winterkill does not appear to be an issue in any of the commercial varieties planted across the region, but some early maturing varieties in our research plots were damaged by the freeze.  Wheat planted in October is jointed (Feekes 6), and some plants are in Feekes 7 (two nodes above the ground).  Wheat planted in November is just beginning to joint.  We have identified a few bird cherry oat aphid infestations in central and southern Hunt County, but most of the area wheat crop has very low numbers of aphids (greenbug and bird cherry oat aphids).  We have not observed any stripe or leaf rust yet.

Louisiana Trey Price (Field Crops Pathologist LSU Ag Ctr, Winnsboro, LS) 31-Mar-2014:  There’s really not much to report at the moment in Louisiana.  Steve spotted leaf rust at Ben Hur Research Station in Baton Rouge a couple of weeks ago, and incidence and severity were low.  I’m unsure of the current status.  We have stripe rust developing in GACT7, a susceptible variety, at the Dean Lee Research Station in Alexandria.  Incidence and severity were less than 1% last week.  In Winnsboro, there are no rust issues on wheat or oats at the moment.  Low incidence and severity of leaf and stripe rust at Crowley (Rice Station, Southwest Louisiana).

Georgia  Dan Bland (Crop & Soil Dept, Univ of Georgia-Griffin) 3-Apr-2014:  We were down visiting our nursery in Plains, GA yesterday and found a lot of leaf rust in a strip of wheat planted about 2 months earlier than the recommended date for the purpose of spreading hessian fly to a small replicated test.  This is done every year so that David Buntin can get pupa and larva counts on the state variety test.  We normally see leaf rust in this area especially if the strip planted is susceptible.  This year Jerry Johnson says it’s the most he’s ever seen for this time of year.  We also saw leaf rust on the lower leaves of the most susceptible lines in another test about 300 yards away.  Leaf rust also has been reported in southeast Georgia.  Plains is in southwest Georgia.

Oregon  Dr. Michael Flowers (Extension Cereal Specialist, Oregon State University, Corvallis, OR) 3-Apr-2014:  After I sent out the note yesterday, reports have been coming in from both the north and south Willamette valley about stripe rust.  Currently there are reports of stripe rust found on Goetze, Kaseberg, Sy Ovation and Tubbs 06.  It appears that maybe we were not as lucky as hoped and that stripe rust did overwinter in some fields throughout (north and south) Willamette Valley

Wheat streak mosaic virus showing up

Add wheat streak mosaic virus to the list of possible causes of yellowing wheat in Oklahoma. Wheat streak mosaic virus is transmitted by the wheat curl mite, which oversummers on grasses such as volunteer wheat and corn. The wheat curl mite cannot survive more than two weeks without a green host, hence the recommendation to make sure that all grass plants are dead two weeks prior to planting. You can find more information on the wheat curl mite and wheat streak mosaic in OSU Fact Sheet EPP-7328 – Three virus disease of wheat in Oklahoma

The photo below is from our wheat variety trial at Kildare. As you can see there is significant yellowing in some of the plots. Our first thoughts were that either wheat soilborne mosaic virus and/or wheat spindle streak mosaic virus were causing the symptoms; however, the yellowing was present in many varieties that are resistant to both these diseases. The Disease Doctor, Bob Hunger, collected samples for analysis in the OSU Plant Diagnostic Lab. Tests showed that wheat streak mosaic was the culprit.

Wheat streak mosaic virus is responsible for yellowing at our Kildare variety trial. All varieties are affected by the disease, but as shown in this picture the severity of the reaction differs somewhat by variety.

Wheat streak mosaic virus is responsible for yellowing at our Kildare variety trial. All varieties are affected by the disease, but as shown in this picture the severity of the reaction differs somewhat by variety.

We are facing this problem because I did not follow my own recommendations. While the plot area was mostly clean at the time of planting, there was some volunteer wheat present. We planted anyway and sprayed glyphosate right after planting. In the past wheat streak mosaic virus was primarily a northwestern Oklahoma issue and we could get by with late burndown on wheat ground in central Oklahoma. Our Kildare plots are a prime example that this is no longer the case. We have to control volunteer grasses (wheat, corn, grain sorghum, etc.) in a manner that will break the green bridge for at least two weeks prior to planting.

So, what is next for our plots at Kildare? There are some variety differences in reaction to the wheat streak mosaic virus. We will rate plots and include this information in our wheat variety comparison chart. I anticipate the plots will continue to go downhill and it is yet to be determined whether or not we will be able to harvest useable data from the location. We will certainly try again next year and apply our turndown earlier.

 

Pictures from southwest Oklahoma

I wanted to share a few pics from Rocky Thacker, Station Superintendent at the OSU Southwest Research and Extension Center near Altus, OK. These pictures were taken on April 8 and clearly show the extent of the current drought’s damage to the southwest Oklahoma wheat crop.

Altus Area Wheat-April 2014 001 Altus Area Wheat-April 2014 002 Altus Area Wheat-April 2014 004 Altus Area Wheat-April 2014 003

Wheat disease update – 31 March 2014

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

Oklahoma: No reports of significant diseases in Oklahoma. Around Stillwater, wheat soilborne/spindle streak mosaic are still showing strong in my screening nursery, but these virus diseases should not be much of a problem around the state due to resistance in nearly all planted varieties. Looking in the same places as 10 days ago, I did find a slight increase in the number of powdery mildew pustules on low leaves, but these pustules still are small and did not appear to be actively sporulating. Wheat is mostly at the Feekes stage 6 but likely approaching stage 7.

Reports/excerpts of reports from other states:
Many thanks to Dr. Amir Inbrahim for sending the report below as this is the most comprehensive disease report I have heard to date from Texas. I interpret his observations to indicate that both stripe and leaf rust are present (especially leaf rust), but that build-up has not yet hit the upper canopy but in this area producers should be ready to “pull the trigger” to protect wheat with high yield potential. In Oklahoma we will need to wait and see if moisture comes to allow inoculum coming from southern Texas to infect the Oklahoma wheat crop.

Texas Dr. Amir Ibrahim (Prof, Small Grains Breeding and Genetics, Texas A&M University) 30-Mar-2014: I have received reports from our research associates, around March 26, 2014, about the rust situation in South Texas.
Castroville, TX: The wheat crop is now at Feekes growth stages 8-10.5. Cultivars such as ‘Everest’ and ‘Billings’ have already headed at this site. There is a uniform spread of leaf rust (P. triticina) in the lower canopy of the spreader rows throughout the field. The infection has not yet moved up into the middle canopy or the flag leaves. It has been raining during the week of March 24th, and the weather forecast calls for temperatures in the high 80’s for the next few days, which will help promote the spread of the infection. Stripe rust (P. striiformis) has spread throughout the replicated trials, especially on the spreader rows of ‘Patton’. The infection was as high as 60S on the flag leaves of some experimental lines. There is uniform spread on TAM 111 in the range of 20-30S, which points to the presence of 2012 virulence. Temperatures have been cooler than normal which helped the spread of P. striiformis at this site. However, the warming temperatures will slow spread at this site but not necessarily at sites farther north if infection has already started.

Wharton, TX: The Wharton uniform rust nursery is located 90 miles south of College Station. The wheat crop is now at Feekes growth stages 8-10.5. ‘Everest’ has already headed at this site.
There is a uniform spread of leaf rust in the lower canopy of the spreader rows throughout the field. The infection is beginning to move into the mid canopy, and we believe mid-April should be a good target date for taking readings at this site.

Beeville, TX: Beeville is located 50 miles NW of Corpus Christi. We have both spring and winter wheat plots and head-rows at this site. The majority of the winter wheat here is at Feekes 5-7 growth stages, whereas the spring wheat is at 9-10. There is a buildup of leaf rust on TAM 112 in the head-rows and on the spreader rows around the yield trial plots.

College Station, TX: The wheat at this site is at Feekes 7-9 growth stages. There is a buildup of leaf rust in the lower canopy of ‘TAM 110’.

Oklahoma wheat update 03/28/2014

On Friday, March 28th I made a tour through northwestern Oklahoma to diagnose a few problem fields and get a better feel for the wheat crop condition. I have provided a brief description of what I saw below. I did not make it to southwestern Oklahoma this trip, but by all accounts the wheat is dry, brown, and barely hanging on. A best case scenario in areas southwest of Apache this year is a poor wheat crop. It will have to rain a lot between now and harvest for this to happen.

Reports from Apache eastward are somewhat better. The wheat crop in this area still has potential, but the potential is declining. A farmer from the Hinton area called yesterday and indicated that moisture could still be found about 1 inch below the soil surface, but the top is still very dry. We need a soaking rain to move nitrogen into the rooting zone and to perk the crop up post dormancy.

My first stop this morning was at Lamont. Wheat in this area is smaller than normal and is at approximately Feekes GS5. There were several yellow areas in fields and uneven wheat. Much of this yellowing appeared to be nitrogen deficiency, but not all of it was due to insufficient top dress nitrogen. We simply have not had enough moisture to get good movement of top dress N into the rooting profile and for the wheat crop to take up applied N. Some of the yellowing was also due to drought stress. Some of the yellowing could have been due to brown wheat mite and/or winter grain mite activity (described more below).

My second stop was at our Cherokee variety plots. Wheat in this area was uneven, similar to Lamont. As shown in the picture below, part of our plot area was showing significant yellowing. Initially, I thought this was due to changes in soil type/nutrient variability. Upon closer inspection, this area was infested with brown wheat mite. These symptoms have only started to show in the last week or so. Thanks to variety trial cooperator Kenneth Failes, this situation will be remedied as soon as the wind settles.

The yellow, stunted areas in our Cherokee variety trial were caused by brown wheat mite

The yellow, stunted areas in our Cherokee variety trial were caused by brown wheat mite

 

Next stop was Alva, where the trend of uneven and yellow wheat continued. As shown in the picture below, there were several fields in the area with spots of dead or nearly dead wheat. Brown wheat mites were found in most of these fields and probably weakened plants which increased the amount of winterkill. In some fields seed had been placed at the proper depth, but the seed trenches were partially filled with residue rather than soil. Residue provides less insulation than soil and likely made heavy residue areas more prone to winterkill. I also noticed in these fields that the crown of the plant had developed in residue rather than soil, which likely increased winterkill. I looked at additional no-till fields in the area with severe winter injury, but plants that were still viable. Grazed fields seemed to have greater injury than non-grazed.

Areas of winterkill in no-till wheat near Alva

Areas of winterkill in no-till wheat near Alva

 

Although seeded at the proper depth, some wheat plants in heavy residue areas had crown placement at the soil surface. This increased the severity of winterkill.

Although seeded at the proper depth, some wheat plants in heavy residue areas had crown placement at the soil surface. This increased the severity of winterkill.

I looked at a few fields south of Enid. Unlike the fields in Grant, Alfalfa, and Woods Counties, this primary issue in these fields was winter grain mite instead of brown wheat mite. The symptoms were areas of the field having a silver tint. Some areas had died or lost several tillers and these areas got bigger as the season progressed and dry conditions worsened.

Field affected by winter grain mite south of Enid. Note the silver tint of the wheat on the left side of the terrace.

Field affected by winter grain mite south of Enid. Note the silver tint of the wheat on the left side of the terrace.

 

I ended my tour at Marshall, Oklahoma where I did not find any insects, but did find some thirsty wheat. All of the insect issues I encountered today can be corrected with scouting and insecticides. Wheat winterkill was present, but rarely affected entire fields and was not that widespread. The primary concern for all of Oklahoma remains lack of moisture. There are some fields in north central and northwestern Oklahoma with good yield potential; however, the best areas are starting to turn blue due to lack of moisture. Another couple of weeks of warm temperatures and wind without rain will turn blue wheat to brown. We need moisture.

Brown wheat mite showing up in winter wheat

by: Tom Royer, OSU Extension Entomologist

Our winter wheat has taken a beating this winter, with cold weather hanging on and some areas not getting that thirst quenching precipitation to help it get a great jump start this spring.  In addition, I have received scattered reports of brown wheat mites showing up and causing problems.  Producers need to remain alert so that their wheat is not suffering dual problems of dry growing conditions PLUS brown wheat mite.

Brown what mite can severely damage wheat that is already stressed due to drought or other adverse environmental conditions.

Brown what mite can severely damage wheat that is already stressed due to drought or other adverse environmental conditions.

Brown wheat mite is small (about the size of this period.) with a metallic brown to black body and 4 pair of yellowish legs.  The forelegs are distinctly longer that the other three pair. Brown wheat mites can complete a cycle in as little as 10-14 days.  They will undergo up to 3 generations each year, but have probably already completed at least one or two by now. Numbers will likely decline if a hard, driving rain occurs.  Spring populations begin to decline in mid-late April when females begin to lay “diapause” eggs.

Brown wheat mite causes problems in wheat that is stressed from lack of moisture.  They feed by piercing plant cells in the leaf, which results in “stippling”.  As injury continues the plants become yellow, then dry out and die.  These mites feed during the day, and the best time to scout for them is in mid-afternoon.  They do not produce webbing and will quickly drop to the soil when disturbed. They are very susceptible to hard, driving rains, but until then they can cause yield loss when present in large numbers

A closeup of a brown wheat mite. Photo courtesy Franklin Peairs, CSU.

A closeup of a brown wheat mite. Photo courtesy Franklin Peairs, CSU.

Brown wheat mites are about the size of a period at the end of a sentence and can be difficult to see with the naked eye.

Brown wheat mites are about the size of a period at the end of a sentence and can be difficult to see with the naked eye.

Research suggests that a treatment threshold of 25-50 brown wheat mites per leaf in wheat that is 6-9 inches tall is economically warranted.  An alternative estimation is “several hundred” per foot of row.

Check CR-7194, Management of Insect and Mite Pests in Small Grains for registered insecticides, application rates, and grazing/harvest waiting periods. It can be obtained from any County Extension Office, at www.wheat.okstate.edu, or by clicking here.

Brown wheat mite eggs in soil.

Brown wheat mite eggs in soil.

 

 

First hollow stem update 03/18/2014

With the exception of Brawl CL Plus, Centerfield, and a few experimental lines all of the varieties in our plots at Stillwater are at first hollow stem. I have posted the measurements from 21 March 2014 below. 

Variety cm of hollow stem 03/21/2014
Endurance .
Deliver .
Pete .
OK Bullet .
OK Rising .
Billings .
Ruby Lee 2.4
Garrison .
Duster .
Gallagher .
Iba 2.6
Everest .
Jackpot .
Doans .
Greer .
CJ .
SY Southwind .
Sy Llano .
Armour .
WB-Cedar .
WB-Redhawk .
WB-Grainfield 3.7
Winterhawk .
WB4458 .
T153 .
T154 .
T158 1.5
LCS Mint 1.5
LCS Wizard .
LCH11-109 .
LCH11-1117 .
LCH11-1130 .
TAM 112 .
TAM 113 .
Byrd .
Brawl CL Plus 0.9
Centerfield 0.8
Doublestop CL Plus 1.9
OK09125 1.1
OK09520 .
OK10126 1.0
OK08707W-19C13 3.4
OK10805W 0.9
OK10728W .
OK11754WF .

Wheat disease update – 21 March 2014

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

Oklahoma:  Diseases are still quiet across Oklahoma.  Gary Strickland (Extension Educator – southwest Oklahoma) indicated he has “seen one leaf rut pustule.”  Also, wheat just has not grown in his area and is just starting to get to the point of tillering but there is so little growth he doesn’t feel there is sufficient growth to support much tillering.  He did indicate he has seen and has a lot of reports of brown wheat mites.

Around Stillwater, the wheat soilborne/spindle streak mosaic is the only disease of prominence.  I did find some small pustules of powdery mildew in the extreme low leaves of ‘Pete’ wheat that was in the range of Feekes 6.  Wheat around Stillwater is in much better condition than in western Oklahoma where drought has been severe.  I also have seen quite a few lady beetles in my trials and plots, but have yet to see any aphids.

Reports/excerpts of reports from other states:

Arkansas  Dr. Gene Milus (Professor/Wheat Pathologist, Univ of Arkansas) 20-Mar-2014:  Jason Kelley, Extension wheat agronomist, found fresh leaf rust pustules on volunteer wheat at the Cotton Branch Experiment Station near Marianna on March 20.

Louisiana Dr. Stephen Harrison (Professor/Wheat Breeder, LSU AgCenter) 18-Mar-2014:  I found leaf rust at the Ben Hur Research Farm in Baton Rouge yesterday.  This was in an early-planted field for Hessian Fly where I found a few pustules around Christmas.  The cold and very wet winter put the rust on hold until recently but it is active and should ‘take off’ now.  I have not received any other rust reports from around the state but will check nurseries in north Louisiana tomorrow.

The wheat crop is a little later than normal and has a much tighter range of heading dates due to the cold winter.  The variety trial probably averages second node but is very rapidly developing.

Follow

Get every new post delivered to your Inbox.

Join 787 other followers