Most of the spring wheat is at or will soon be at flowering. One disease that can develop in wheat at this growth stage is Fusarium head blight (FHB or scab). The FHB pathogen infects the wheat head through the senescing flowers and can cause reduced yield and accumulation of mycotoxins, mainly deoxynivalenol (DON). Wheat grain with more than 2ppm can be docked for price at the elevators. The only in-season FHB management strategy is timely application of a fungicide at flowering. Since by the time FHB symptoms develop, it would be too late to apply a fungicide, an FHB prediction tool can be very helpful in gauging the risk for FHB. Currently, the FHB risk is showing to be moderate to high for a few areas in the eastern half of the state. For fields in these areas where spring wheat is at flowering, a fungicide is recommended to manage FHB. Keep checking on this FHB prediction tool when deciding on FHB fungicide application.

A few fungicides that are effective against FHB include Prosaro, Miravis Ace and Caramba. These fungicides have been tested widely in the region and provide protection against FHB and other fungal leaf diseases. Based on diseases developing in winter wheat such as powdery mildew, stripe rust, leaf rust, and tan spot; a fungicide applied for FHB management would also protect against these fungal leaf diseases.

--Emmanuel Byamukama, Extension Plant Pathologist , South Dakota 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

Small Grains Disease Update 06/22/2020

Little changed in both the risk models or reports that I received this past week. I suspect there is some stripe rust and crown rust here and there across the southern half of the state, while tan spot is probably the only fungal disease you might find in the northern half of the state as of today.
That is likely to change in the near future as much needed rain fell across much of the state when a couple of cold fronts brought relief from the blast-furnace heat and wind of the first half of last week. While the risk of leaf rust infections has already started trending higher over the weekend for all but the northeastern edge of the state, the risk of infection for FHB will start to increase by tomorrow.
The heat in the first part of last week continued to push the development of the spring wheat crop and the first spring wheat fields reached heading over the weekend in the northwest part of the state. This means that you will need to actively scout individual fields to determine the current growth stage, and locate whether you have tan spot, stripe rust, or possibly even leaf rust near the bottom, middle, or top of the canopy.
The hot windy weather itself or the herbicides applied during the hot windy weather may have caused physiological speckling or discolorations that can easily be mistaken for one of the foliar fungal diseases. Remember that tan spot, septoria, stripe, and leaf rust almost always start near the bottom of the canopy and move upwards to newer leaves as the growing season progresses. You should therefore always find worse symptoms of the same diseases lower in the canopy. Bacterial Leaf Streak (BLS) is an exception to this rule of thumb.
While your scouting you may wonder what the yield potential of the spring wheat crop is. People have already commented to me that the crop seems very short this season. I'll repost a Minnesota Crop News article about the lack of height of the crop and whether that spells disaster before grain fill even has started.
The weather forecast for the coming week looks very favorable for grain fill for winter wheat, rye, and the earliest spring wheat, barley, and oat fields as daytime highs not forecasted to exceed 85 and nighttime lows will remain in the low to mid-fifties for much of the state.
Bring your rubber boots
--Jochum Wiersma, Extension Agronomist, University of Minnesota Crookston

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

Over the past week, there have been several reports of wheat and barley heading across the state and now is the time to start monitoring scab risk. Most areas of the state with a heading small grain crop are under low scab risk (drought stress), however there are a few pockets with higher risk. According to the model, risk is moderate to high for susceptible varieties in the eastern quarter of the state and for a small pocket in northwestern ND. Scab risk for moderately susceptible (score of 5-6 in the selection guide) and moderately resistant (score of 4 in the selection guide) varieties is low across the state. As a reminder, the best time to apply a fungicide for FHB in wheat is at early flowering, and the best time in barley is at complete head emergence.

--Andrew Friskop, Cereal Extension Pathologist, NDSU Department of Plant Pathology

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

Welcome to the Fusarium Head Blight Prediction Center, 2020. The system has undergone some revisions this year. The new interface focuses on the map-based risk of disease for the current date. Users can select other dates of interest from the menu in the upper portion of the interface. The date selected should correspond to times when your wheat is flowering, because the crop is most susceptible to infection at this stage. There is also a menu icon in the upper left corner that allows users to customize the model predictions for winter vs. spring wheat, and account for wheat varieties with different levels of genetic resistance to Fusarium head blight.

The focus of the prediction effort is currently on Northern South Dakota, Southern North Dakota, Central Minnesota, Wisconsin and the “thumb” area of Michigan where winter wheat is likely at the heading and flowering stages of growth. The models indicate a moderate or high level of risk for susceptible wheat varieties in portions of South Dakota, and North Dakota. Growers in these areas should consult with local advisors to determine what other local factors that might also influence the risk of disease.

--Erick De Wolf, Department of Plant Pathology, Kansas 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

The first instances of stripe rust, crown rust, and barley yellow dwarf were confirmed in winter wheat and oats, respectively, this past week in southern Minnesota. Meanwhile, tan spot is prevalent in wheat following wheat in the northern half of Minnesota.

These findings are all in line with expectations/risk models. The conditions for tan spot, for example, have been favorable across much of the northern half of the state for seven out of the last ten days.
One of the characteristic symptoms of early-season tan spot infections is a yellowing discoloring of whole leaves. This is a more extreme expression of the same yellow halo that surrounds the tan spot lesions in more mature plants. Be careful not to mistake this yellowing for a nitrogen deficiency.

Research at both NDSU and the University of Minnesota has shown that the early onset of tan spot yield can results in yield reductions of 4 to 5 bushels if conditions continue to favor the development of the disease. Use half a labeled rate of a registered fungicide to halt/slow down the disease progression. Most of the labeled fungicides can successfully be tank-mixed with the commonplace herbicides. Always check the label of both the herbicide and fungicide for tank mix restrictions.

Research at the Northwest Research and Outreach Center has shown that the combination of any of the EC formulations of fungicides in combination with common wild oat herbicides and bromoxynil + MCPA can result in bromoxynil injury in both wheat and wild oats. This injury generally did not affect grain yield of the wheat or the control of the wild oat.

A nitrogen deficiency can readily be identified as the symptoms are worst on the oldest leaves and start at the tip of the leaves, progressing towards the base as the deficiency gets worse. This is in contrast to the yellowing caused by tan spot, which will start from the initial lesions and migrate up and down the leaf blade from the initial point of infection. The causes of the N deficiencies are several, all of which have a common denominator, namely excess precipitation. Excessive rainfall causes leaching, denitrification, and the inability of the plants to take up available N

Leaching is a potential problem in coarser textured soils. Saturated soils/standing water will cause both denitrification and inability to take up available N. As soils are saturated, the plant’s roots also are unable to take up N - even if available. Often the crop recovers quickly if the growing conditions improve and the excess water has drained. If the N deficiency is severe, a supplemental application of N as either urea (46-0-0) or urea ammonium nitrate solution (28-0-0) can be advantageous.

The earliest seeded spring wheat in the southern half of the state will likely reach anthesis sometime this week. To date, the risk models Fusarium head blight have been trending relatively low. This is largely the result of the lack of precipitation the past two weeks across a large swath of southern half of the State. The lower dew points further help reduce the risk of the disease to develop. Focus the scouting efforts on the presence of foliar diseases and still consider a fungicide application at anthesis if you detect tan spot, Septoria, and/or one of the rust on the flag leaf, penultimate leaf or the second leaf below the flag leaf.

--Jochum Wiersma, Extension Agronomist, University of Minnesota Crookston

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

Winter wheat is approaching flowering and some of the earliest planted barley may be heading this week. Currently, most of the state is at low risk for FHB, but a few pockets of moderate risk are developing in south central and northeastern ND. Most of the state received rain last week and the forecast for this week shows sporadic rain events with high dew point temperatures. As a reminder, the best time to apply a FHB fungicide in winter wheat is at early-flowering (and up to 6-7 days after) and the best time for barley is complete head emergence (and up to 6-7 days after). The most effective fungicides are Caramba, Miravis Ace and Prosaro.

--Andrew Friskop, Cereal Extension Pathologist, NDSU Department of Plant Pathology

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

Most winter wheat fields and nearly all winter barley fields in New York are now past flowering stages and beyond the period for effective fungicide application. There was a predicted, medium to high risk of FHB infection of susceptible winter cereal varieties that flowered in early June in certain areas of the state. Growers are advised to scout their crops over the next few weeks (ideally at kernel soft dough stages) for symptoms of Fusarium head blight in order to assess the likelihood of deoxynivalenol contamination in grain and to plan their harvest strategies and post-harvest marketing of grain. Foliar diseases generally have occurred at minor severities to date. Stripe rust has not been observed beyond individual wheat fields in Seneca and Wayne Counties.

Spring malting barley is progressing rapidly through growth stages with many fields approaching flag leaf emergence, and some fields of ‘Conlon’ barley in the Hudson Valley already emerging from the boot. Spring barley growers are urged to track growth stage closely and to consider a spray with Caramba, Prosaro, or Miravis Ace as soon as most heads are fully emerged (up to 7 days beyond head emergence if necessary). Application of these fungicide products should be based on Fusarium head blight (FHB) risk as well as the risks of powdery mildew, rusts, and fungal leaf blotches in the upper canopy based on scouting of individual fields. Low levels of barley leaf rust have been observed in winter barley and could be a bigger factor in spring barley if moist, humid conditions occur over the next few weeks. Fungicide products containing QoI (FRAC Group 11) fungicides should not be applied to headed barley as they may result in increased levels of DON in grain. Check the Fusarium Risk Assessment Tool (http://www.wheatscab.psu.edu/ ) and your local weather forecast frequently through the head emergence period for spring cereals.

-- Gary Bergstrom, Extension Plant Pathologist, Cornell 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

Welcome to the Fusarium Head Blight Prediction Center, 2020. The system has undergone some major revisions this year and it may help to take a few minutes to familiarize yourself with the new tools. The new interface focuses attention on the map-based risk of disease for the current date. The calendar icon at the top of the interface allows users to select dates of interest. The date you select should correspond to times when your wheat is flowering, because the crop is most susceptible to infection at this stage. There is also a menu icon in the upper left corner that allows users to customize the model predictions for winter vs. spring wheat, and account for wheat varieties with different levels of genetic susceptibility to Fusarium head blight.

The focus of the prediction effort is currently on Nebraska, Northern Illinois, Northern Indiana, Northern Ohio and Central Pennsylvania where wheat is already at the heading and flowering stages of growth. The models indicate a moderate or high level of risk for wheat varieties in portions of Ohio and Pennsylvania. Growers in these areas should consult with local advisors to determine other local factors that might also influence the risk of disease.

--Erick De Wolf, Department of Plant Pathology, Kansas 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

Most of the winter wheat in South Dakota is now at flowering. This growth stage coincides with the Fusarium head blight (FHB or scab) disease development. Currently the FHB prediction tool is showing the central parts and a few scattered areas in west SD to have moderate to high risk for FHB to develop. The limited rain for certain areas and high temperatures have lowered the FHB risk. However, change in weather (rainfall and warm temperatures) will affect the risk. Wheat is still at risk of FHB until shortly after flowering. A fungicide labelled for FHB if applied at flowering can lower FHB and vomitoxins (mainly DON) in wheat grain. The best fungicide timing for FHB management is at flowering (50% of the plants have flowers developing). Growers in the areas with the moderate to high FHB risk should consider applying a fungicide to manage FHB. Fungicides that have been found to be effective against FHB include Prosaro, Caramba, and Miravis Ace when applied at flowering growth stage. Growers should keep checking on the prediction tool until wheat is done flowering to decide on the need for a fungicide.

--Emmanuel Byamukama, Extension Plant Pathologist , South Dakota 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

Wheat in the Northern part of the state has started to flower this week, whereas wheat in the central part of the state has just finished flowering. Warm, wet weather will continue to elevate FHB risk in flowering wheat, and a fungicide application of Caramba, Prosaro, Proline, or Miravis Ace are suggested at this time. Applications are most efficacious when made following label directions between the start of flowering and 5 days after this point in time. Flowering is defined as the point in time when 50% of main tillers have started to push anthers. Do not apply products containing strobilurins for FHB management.

Wheat in the southern part of the state should now be showing symptoms and signs of FHB if severe infection occurred (bleached heads/portions or heads/spikelets with salmon colored growth). Recent surveys indicate that overall FHB levels are likely low in this part of the state. The central part of Illinois however, was under high risk across wheat resistance levels during the critical flowering period and should be monitored closely over the coming days. Symptoms of FHB will be most observable 18-24 days after flowering. If severe FHB is detected, you should be prepared to take measures to remove contaminated grain. These include increasing combine fan speeds and openings to blow out lightweight, FHB-infested grain, harvesting infected fields as early as possible (and preferably first) and if possible, storing grain from infested fields separately from quality grain. Ensure that grain is dried (15% optimal) to minimize continued growth of pathogen and DON accumulation in storage.

-- Nathan Kleczewski Ph.D., University of Illinois, Research Assistant Professor and Extension Specialist

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