FHB Alert Blog

FHB Update from OK, 05/05/17

Nearly all of the wheat I saw this past week was along a line for about 100 miles west of Stillwater. Wheat around Stillwater is at the milk to soft dough stage. Wheat west of Stillwater ranged from full kernel to full kernel-milk. In this area, I saw both good and bad wheat. Much of the bad wheat I saw had been hit with wheat streak mosaic (WSM). To date, the Plant Disease and Insect Diagnostic Lab (Ms. Jen Olson, Director) has assessed about 82 wheat samples from 19 counties for Wheat streak mosaic virus (WSMV), High plains virus (HPV), and Barley yellow dwarf virus (BYDV; PAV strain). These 19 counties are located west of Stillwater, and mostly are
west of I-35. Of these 82 samples, 56 were positive for WSMV, 11 were positive for HPV (all 11 co-infected with WSMV), and 42 were positive for BYDV. Four of the samples were positive for all three viruses. These figures indicate the severity of wheat viruses in Oklahoma this year. Reports from other states indicate this problem (mite transmitted viruses such as WSM) is just as severe up through the central plains. The cool, wet weather we have had can mitigate the effects of WSM and BYD, and help infected plants to continue to mature and finish. This would be especially true for plants/fields that were infected in the spring. However, yield and test weight will be affected especially if wheat was infected in the fall. For more information on mite-transmitted wheat viruses such as WSM, please see OSU Fact Sheet EPP-7328 (Wheat Streak Mosaic, High Plains Disease, and Triticum Mosaic: Three Virus Diseases of Wheat in Oklahoma) available at http://pods.dasnr.okstate.edu/docushare/dsweb/HomePage

Regarding leaf and stripe rust, I have seen mostly leaf rust over the last week, but signs of stripe rust (both active and inactive) also can be observed. On susceptible varieties that were not sprayed, leaf rust was severe (≥60% flag leaf area showing pustules). In his nurseries at Lahoma in north-central OK, Dr. Brett Carver (OSU Wheat Breeder) is seeing some active and inactive stripe rust. Given our cool and wet weather, stripe rust appears to be re-activating. Dr. Carver also is seeing abundant and severe leaf rust.

--Bob Hunger, Extension Plant Pathologist, Oklahoma State University

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from PA, 05/05/17

Over the next several days, our risk levels for FHB are dropping due to low temperatures. Much of PA is experiencing rains that would prevent spraying at this time anyway. Monitor closely as we go into next week to see if increasing temperatures and possible scattered rains increase our risk. Much of the barley in southern PA has headed and may be flowering or a bit past flowering now, but if you get a window to spray, even if you feel like you may be late, you can take it. The plants should be dry when you make your application, but a shower soon after application probably won’t wash much, if any, product off.

Wheat across the southern part of PA has begun to head out. In these areas, we can expect the first flowering around the middle of next week. Be prepared to spray a fungicide on fields that are at the beginning of flowering, up to about 5 days following the beginning of flowering. Remember, sprays applied PRIOR to flowering will NOT provide significant suppression of scab or toxin production. Caramba or Prosaro are effective on scab and give control of most leaf diseases and glume blotch. They do not need to be tank mixed with another product to control these diseases. If these products are unavailable, Proline and Folicur (which together provide the same chemicals as Prosaro) may be tank mixed at a rate of 3 + 3 fl oz/A. Spray nozzles should be angled at 30° down from horizontal, toward the grain heads, using forward- and backward mounted nozzles or nozzles with a two directional spray, such as Twinjet nozzles. Do NOT use any strobilurin-containing fungicides at heading or beyond.

--Alyssa Collins, Extension Field Crops Pathologist, Penn State University

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from DE, 05/05/17

Rains will continue to keep in elevated risk levels for FHB in varieties currently flowering (Kent Co Delaware and similar latitudes in Maryland), and slightly North. Growers with wheat flowering at this time may consider an application of a FHB fungicide (Caramba, Prosaro, Proline). Applications are most efficacious when applications occur from the start of flowering (50% of MAIN tillers with anthers extruded), through 6 days from the start of flowering. Efficacy is significantly reduced when applied outside of this window. Apply in 5 gal/A air and 15 gal/A by ground, 300-350 um droplet size, with nozzles at least angled forwards 30 degrees. Wheat not yet flowering is not at risk. Continue to check your wheat and this page for updates. For more information follow this link: http://extension.udel.edu/fieldcropdisease/2017/05/05/fungicide-applicat...

--Nathan Kleczewski, Extension Field Crop Plant Pathologist, University of Delaware

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from IN, 05/04/17

Wheat flowering across southern and central Indiana is at moderate to high risk for Fusarium head blight, according to the latest risk map predictions. Fungicide applications should be applied at early flowering to be most effective. Indiana research indicates that applications of the fungicides Prosaro and Caramba are most effective at managing FHB if they are applied at early flowering (Feekes growth stage 10.5.1). Other products are available, but may not be as effective. If the recent rains or other factors delay application and risk for FHB is high, Purdue University research indicates that fungicides applied a few days after flowering can reduce DON compared to no fungicide application.

--Kiersten Wise, Extension Plant Pathologist, Purdue University

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from VA, 05/02/17

Following last week's rain, the risk for Fusarium head blight (FHB) infections has increased, and the risk is very high even for moderately resistant varieties in certain portions of the state. Much of the wheat crop is beyond the early flowering stage, but for fields where wheat is currently flowering a fungicide may be needed to protect the crop from FHB infection and DON contamination. Recommended fungicides include Caramba, Prosaro, and Proline. Fungicides are most effective when applied at the start of flowering and up to a week later. The greatest coverage of the heads can be achieved by applying fungicides in 5 gal/A by air and 15 gal/A by ground with a 300-350 um droplet size and nozzles angled forward at least 30 degrees.

--Hillary Mehl, Extension Plant Pathologist, Virginia Tech

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from OK, 05/01/17

The last three days of last week were spent in southwestern (Altus), central OK (Apache & Chickasha) as well as here around Stillwater. Wheat I saw at those locations ranged mostly from milk to soft dough, with some even approaching medium dough. I’m not sure about wheat in northern OK and over into the panhandle. The Panhandle is of particular interest with the far western parts of it receiving significant snow (up to 6-12 inches I heard on weather reports around Boise City).

Flag leaves on wheat across southwestern and in central OK are mostly gone as a result of rust (both stripe and leaf, but primarily leaf rust I think), wheat streak mosaic, and barley yellow dwarf. I saw little active stripe rust, but did see more active leaf rust. An abundance of leaves showed rust telia, but again, mostly leaf rust (I think). I also saw scattered white heads in wheat at Altus. Examination showed dark lower stem internodes and splitting of stems revealed cottony fungal growth in the lowest internode with a reddish/pinkish color indicating Fusarium root rot as the most likely cause. A sample of white plants with mostly sterile heads was brought to a field day at Apache, OK in central OK; examination revealed take-all as the likely cause. Barley yellow dwarf was present at all locations, but seemed more prominent at Chickasha.

As in my last update, Wheat streak mosaic virus (WSMV) continues to be found and reported across a large area of western Oklahoma. The cool wet weather will likely help manage infected plants to continue to mature, but yields definitely will be significantly impacted. For more information on mite-transmitted wheat viruses such as WSM, please see OSU Fact Sheet EPP-7328 (Wheat Streak Mosaic, High Plains Disease, and Triticum Mosaic: Three Virus Diseases of Wheat in Oklahoma) available at http://pods.dasnr.okstate.edu/docushare/dsweb/HomePage

--Bob Hunger, Extension Plant Pathologist, Oklahoma State University

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from MD, 05/01/17

Wheat is currently flowering in Maryland, and this is the most vulnerable stage of Fusarium infection. With the recent showers that we have had, the Fusarium Head Blight risk in the state is very high. Growers are advised to apply fungicides now to reduce the damage. Applications past the stage of flowering will not be of any help. Caramba, Prosaro, and Proline are the most effective fungicides against FHB. Do not apply a strobilurin-containing fungicide. Aerial application at a rate of 5 gallons per acre or ground application at 15 gallons per acre with 300-350 um droplet size and nozzles angled down 30 to 45 degrees from horizontal is recommended.

--Nidhi Rawat, Plant Pathologist, University of Maryland

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from KY, 05/01/17

Much of the wheat in Kentucky is now past the stage of applying a foliar fungicide for protection against Fusarium head blight. However, some late-planted fields and some late-maturing varieties may be at the beginning flowering stage now. Based on the rainfall that has occurred over the last several days, wheat that is flowering in Kentucky is at a high risk for Fusarium head blight.

--Carl Bradley, Extension Plant Pathologist, University of Kentucky

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from DE, 05/01/17

Rain has pushed a large portion of the region into a severe level of risk for FHB if that wheat is currently flowering. Most of the wheat in S Delaware and S Maryland likely started to flower late last week and is at elevated risk for FHB, especially if a suceptible variety was planted. Growers with wheat flowering at this time are advised to make an application of a FHB fungicide (Caramba, Prosaro, Proline). Applications are most efficacious when applications occur from the start of flowering, through p days from the start of flowering. Apply in 5 gal/A air and 15 gal/A by ground, 300-350 um droplet size, with nozzles at least angled forwards 30 degrees. Wheat not yet flowering is not at risk. Continue to check your wheat and this page for updates.

--Nathan Kleczewski, Extension Field Crop Plant Pathologist, University of Delaware

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

FHB Update from PA, 04/27/17

Welcome to the Fusarium Head Blight Risk Assessment Tool for 2016! If you are new to this risk tool or haven’t used it in a while, please click and read the “User Guide” on the left hand side of your screen. The first paragraph has the main steps to get you started with the model. Our small grains in PA got head start on growth due to warm conditions this spring. If you intend to protect your barley from Fusarium head blight (a.k.a. head scab), be prepared to spray a triazole fungicide in the next few days. See my article here for details: http://extension.psu.edu/plants/crops/news/2017/04 Right now the wheat in the lower part of the state is anywhere between Feekes 7 and 8. I’ll update this commentary with more frequency as we approach heading in PA. If you’d like to receive updates directly to your e-mail or via text, please sign up at http://scabusa.org/fhb_alerts.

--Alyssa Collins, Extension Field Crops Pathologist, Penn State University

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org

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