Category: Wheat

Strategies for Minimizing FHB Related Price Discounts at Harvest

wheat infected with head scab
Nidhi Rawat, Small Grains Pathologist | nidhurw@umd.edu
University of Maryland, College Park

Reposted from the US Wheat and Barley Scab Initiative

It’s almost harvest time and Fusarium head blight (FHB) can reduce wheat and barley grain yield and quality, leading to price discounts due to Fusarium-damaged kernels (FDK), deoxynivalenol (DON), and reduced test weight. If your fields are affected by FHB, adjusting your combine settings can help improve grain quality and reduce losses. Additional strategies such as increasing the fan speed, keeping scabby grain separate, testing for DON, and cleaning of grain can also make a difference. Here are a few strategies to consider for minimizing price discounts at harvest.

Based on a study in the journal Plant Disease, modifying combine settings to increase fan speed and shutter opening could improve grain quality and reduce price discounts enough to counteract the reduction in harvested grain compared to the standard combine setting.

Researchers tested four combine configurations:

Plots with varying levels of FHB index were harvested with each combine setting. Compared to the standard setting (C1), settings C2, C3, and C4 led to lower estimated price discounts by $10 to $40 per ton (see table below). C3 and C4 gave the biggest reductions in price losses by improving grain quality.

Table. Grain quality and price discounts for plots with varying levels of FHB index harvested with four different combine configurations.

The estimated gross income was higher with combine settings C2 and C4, with C4 having the most consistency performing well across different levels of FHB index (5 to 35%) and grain prices ($118 to 276/t).

Key Takeaway Messages:

  • Increasing airflow to remove scabby kernels is a profitable strategy.
    • In this study, increasing airflow through the combine by increasing fan speed (from 1375 to 1475 rpm) or by increasing shutter opening (from 70 to 90 mm) optimized profitability, as the reduction in discounts due to scabby kernels was enough to offset the loss in revenue due to reduced yield.
  • However, be careful not to increase airflow by too much.
    • In this study, increasing both fan speed and shutter opening did not optimize profit, as the marginal improvements in grain quality were not enough to overcome the increased yield loss.
  • Although plot combine configurations are not directly applicable to field-scale equipment, know that you can fine-tune your combine airflow settings to improve profitability when harvesting FHB-damaged grain.

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Keep an Eye Out for Cereal Leaf Beetle in Wheat Fields This Spring

Hayden Schug, Agriculture Agent | University of Maryland Extension, Charles County | hschug@umd.edu 
Ben Beale, Principal Agriculture Agent | University of Maryland Extension, St. Mary’s County | bbeale@umd.edu 

Cereal leaf beetle (CLB) is a familiar pest for Maryland wheat growers, and this time of year is ideal for scouting. We often find cereal leaf beetles while scouting for foliar disease like powdery mildew and stripe rust or checking wheat for flowering stage in preparation for fusarium head scab fungicide applications. While both adults and larvae can be present, it’s the larvae (Fig. 1) that cause the most damage. Often mistaken for bird droppings, these larvae feed aggressively on leaf tissue, potentially leading to significant yield loss in wheat if populations are high enough. In Southern Maryland we have found low populations of cereal leaf beetle larvae feeding in wheat throughout most fields. However, only one of these fields met the threshold that would warrant an insecticide application, so it’s important to understand threshold levels. 

Beetle larvae feeding on a wheat leaf
Figure 1. Cereal Leaf Beetle larva on wheat. (Hayden Schug).

Adult CLBs (Fig. 2) overwinter in wooded areas and field edges, becoming active as temperatures rise in early spring. They move into small grains and lay distinctive orange or yellowish eggs on the upper surface of wheat leaves, typically singly or in short rows. After hatching, the larvae feed for two to three weeks, chewing narrow, elongated strips between the leaf veins. This results in a “windowpane” effect—thin, transparent patches where only the leaf epidermis remains (Fig. 3). Larvae appear dark and slimy due to a coating of fecal material, though they are actually yellow underneath. When walking through a field with CLB present, a tell tale sign is black stains that appear on pants legs. 

Beetle on a wheat leaf
Figure 2. Adult Cereal Leaf Beetle on wheat. (Hayden Schug).

Leaf beetle larvae on a wheat leaf with feeding damage from the beetles
Figure 3. Feeding Damage (Peter Oetelshofen, Adobe Stock).

Scouting should begin in late March or early April, especially in no-till fields, those near wooded areas, or where there is a history of CLB infestation. When scouting, check 10 tillers at 10 random locations per field and look for larvae, eggs, or adult beetles, which have shiny blue wing covers with reddish thoraxes and legs.

Treatment is recommended when there is one larva per flag leaf after boot stage. If treatment is necessary, insecticides containing pyrethroids such as lambda-cyhalothrin (Warrior) or zeta-cypermethrin (Mustang Max) are effective. Be mindful of insecticide rotation to avoid resistance, and always check pre-harvest intervals.

Scouting and timely management are key to minimizing the impact of cereal leaf beetle. Keep an eye on your fields while out scouting to determine if you need to add an insecticide to your fungicide treatments.

Maryland Regional Crop Reports: July 2024

Reports are for crop conditions up to July 5, 2024.

Western Maryland

Dry, dry, dry. The pleasant spring has turned into a dry summer so far. Even when the heat isn’t oppressive, the sun is bright, and the wind blows all wonderful conditions for drying out things. Corn and full-season bean planting is a memory. Wheat harvest is in full swing, and yields and test weights are good. Two cuttings of alfalfa are off, and we are hoping for enough moisture to make a third cutting. Double-crop beans are going in the ground, further proving that farmers are the most optimistic people on the planet. Until next month, keep looking up. One day, those clouds will have rain in them, and we will need it.—Jeff Semler, Washington Co.

Central Maryland 

The wet spring resulted in lots of slugs and replanted soybeans. However, in the last few weeks, the rain has disappeared here in Montgomery County. Temperatures have soared into the upper 90s, resulting in some very dry topsoil, subsoil which is quickly losing moisture, and drought-stressed crops. Some corn fields are starting to tassel, and soybeans are beginning to flower.—Kelly Nichols, Montgomery Co.

Northern Maryland

June was unusually dry and we are in a drought situation. Wheat and barley harvest and straw baling was a breeze to the dry weather, and harvest came about 1-2 weeks earlier than normal due to the dry, windy June. Yields were not near the record-setting numbers we’ve seen the past two years but they were still respectable. Having small grains off early will greatly benefit double-crop soybeans, assuming there’s enough moisture in the ground to germinate them. Earliest planted corn is in tassel by July 4 and we thankfully got a couple of decent storms just as tassels were pushing through and alleviated drought scenarios in many fields; that rain likely saved several bushels. Full season soybeans are also starting to come along nicely now after a slow start that some moisture is back in the soil.—Andy Kness, Harford Co.

Upper and Mid Shore

Center pivots have been working double time, keeping corn and soybean fields in the region irrigated amid the ongoing dry spell. Significant rain events are a distant memory, and the summer solstice has brought record heat, contributing to visible water stress symptoms on non-irrigated fields. All corn acres are planted, and early-planted corn is currently tasseling. Small grain harvest is progressing well, aided by the dry weather, which has extended the harvest window. As the small grain harvest wraps up, double-crop beans will soon be planted. Meanwhile, sprayers are busy applying post-emergence herbicides to fields to manage pre-emergence weed escapes, most likely due to the absence of an activating rain. Hopefully we get some rainfall soon.—Dwayne Joseph, Kent Co.

Lower Shore

We had a very dry couple of weeks. Crops were showing signs of drought stress with stunting and leaf burning in some fields. This was followed by a 2-4” rain event across much of the Lower Shore. Corn is approaching late vegetative stages, but not yet tasseling. Wheat has been harvested and double crop soybean planted.—Sarah Hirsh, Somerset Co.

Southern Maryland

No report.

*Regions (counties):
Western: Garrett, Allegany, Washington. Central: Frederick, Montgomery, Howard. Northern: Harford, Baltimore, Carroll. Upper & Mid Shore: Cecil, Kent, Caroline, Queen Anne, Talbot. Lower Shore: Dorchester, Somerset, Wicomico. Southern: St. Mary’s, Anne Arundel, Charles, Calvert, Prince George’s

Maryland Regional Crop Reports: June 2024

Reports are for crop conditions up to June 6, 2024.

Western Maryland

I have a  good friend who says, “I don’t have forty years of experience farming; I have one year’s experience forty times.” This spring has been just like that. We have had more moisture than last year, but then came the hot days, cool weather, and more moisture. Corn is planted, and the first cutting of hay is in the barn. Soybean planting is winding down, and grain harvest will be here before you know it, starting with barley. With the moisture we will see how much disease took its toll. Fungicide applications weren’t always as timely as we would hope because of the frequent showers. Until next month when harvest is underway it is then the story will be told.—Jeff Semler, Washington Co.

Central Maryland 

Planting is almost complete. Slugs have been an issue; some soybean fields will need replanting. It was getting a bit dry, which did provide a good hay-making window. However, a thunderstorm is rolling in as I write this, giving us some needed moisture. Small grains are looking good. Summer annual weeds like pigweed, crabgrass, and foxtail are starting to take off with this warmer weather.—Kelly Nichols, Montgomery Co.

Northern Maryland

Spring has been a little challenging in our area. A dry spell in mid-late April made herbicide efficacy less than ideal, followed by several weeks of a lot of rain, which activated herbicides but prevented the timely termination of other cover crops. Early planted corn and beans are up and out of the ground, with earliest planted corn around V6 and getting it’s second shot of nitrogen. Rainy weather in late April early May delayed planting the remainder of the crop by about two weeks. These later planted fields are much further behind than usual but are looking good. There has been some slug damage present, it gets worse the further west you go in the region. Barley nearing harvest and wheat is starting to turn. There are symptoms of head scab but it remains to be seen how severe DON levels are in the grain. The wet weather has made it very difficult to make timely dry hay.—Andy Kness, Harford Co.

Upper and Mid Shore

Corn acreage is looking good, with a nice color and uniform growth. Depending on when it was planted, corn is in the V2 to V5 stages right now. Most of our full-season soybeans are already in the ground. As usual, rain across the region has been hit or miss, with some areas getting a lot more than others. These downpours might not be ideal, but they’re certainly better than no rain at all. Barley harvest is just around the corner. Summer annual weeds are popping up and are ready to impact yield potential. If your residual herbicide program hasn’t kept them in check, now’s the time for a POST application. And remember, using multiple modes of action in your tank-mix slows down the evolution of herbicide resistance in weeds.—Dwayne Joseph, Kent Co.

Lower Shore

has been planted and currently in emergence stage to around V4 stage. Corn is looking good, and being sprayed to combat early season weeds. Soybean planting is currently underway. In a few instances, early planted soybean (early April) had to be replanted due to slug damage. Wheat is looking good and drying down. Farmers are gearing up to cut wheat, which is earlier than anticipated.—Sarah Hirsh, Somerset Co.

Southern Maryland

As I write this, a very welcome rain is falling outside my window. As we move into the hotter days of June, the old adage that we are only a week away from a drought at any time is holding true. Two weeks ago it was too wet to get into fields and this week we have corn fields starting to show curling leaves and drought stress. In general corn is off to a good start with most sidedress N applications completed. There have been a lot of catch up full season beans planted in the last 2 weeks. Slug feeding has been minimal this year. Barley is drying down with harvest expected any day. Wheat will not be far behind. Ryegrass continues to be a challenge for producers in both burndown situations in corn and beans, as well as small grains. Many fields may need a harvest aid to kill the ryegrass and allow for timely harvest of wheat. Given the wet conditions following flowering, we are encouraging producers to get the wheat crop off as quick as possible to maintain grain quality.—Ben Beale, St. Mary’s Co.

*Regions (counties):
Western: Garrett, Allegany, Washington. Central: Frederick, Montgomery, Howard. Northern: Harford, Baltimore, Carroll. Upper & Mid Shore: Cecil, Kent, Caroline, Queen Anne, Talbot. Lower Shore: Dorchester, Somerset, Wicomico. Southern: St. Mary’s, Anne Arundel, Charles, Calvert, Prince George’s

Fusarium Risk Assessment: 5/13/24

Nidhi Rawat, Small Grains Pathologist
University of Maryland, College Park

Wheat in Maryland has either already flowered or is finishing-up flowering. The FHB prediction maps for today and up to the next 6 days predict high FHB risk. If your wheat is still in the window for FHB fungicide application (from flowering up to the following 4-7 days) you should consider the application of FHB fungicides: Miravis-Ace, Prosaro, Prosaro-Pro, or Sphaerex. These fungicides are also effective against other fungal foliar diseases such as stripe rust, powdery mildew, and tan-spot etc. Strobilurin-containing fungicides are not recommended for application at this stage.

Fusarium Risk Assessment: 5/9/24

Nidhi Rawat, Small Grains Pathologist
University of Maryland, College Park

Wheat is mostly ending flowering across Maryland now, except for some late-planted fields. The FHB prediction map shows enhanced FHB risk. If your wheat flowered within the past 4-7 days, you are still in the window for FHB fungicide application. This season, we are also observing several foliar diseases such as stripe rust, powdery mildew, BYDV, and tan-spot in our variety trial plots. Some farmers are also reporting these issues from their fields. If you are considering the application of fungicides at this stage, use FHB fungicides: Miravis-Ace, Prosaro, Prosaro-Pro, or Sphaerex. These will control other fungal diseases, in addition to FHB, but not BYDV. For BYDV none of the fungicides can provide control, as it is a viral disease, and genetic resistance is the only real solution for it. Strobilurin-containing fungicides are not recommended for application at this stage.

Maryland Regional Crop Reports: May 2024

Reports are for crop conditions up to May 3, 2024.

Western Maryland

April has brought us many showers. The triticale is all in the silos for the most part, and corn planting has begun. The wheat and the barley are looking good. Producers have a keen eye out for FHB, and thus, fungicide is on the docket. Pastures are looking good and first cutting alfalfa is not far off. Warmer temperatures are on the horizon.—Jeff Semler, Washington Co.

Central Maryland 

The wet, cool spring has turned into a hot, dry spring this week. Currently, the highest chance of rain (about 60%) is for this weekend. Planting is in full swing, and the first cutting of orchardgrass will start in a couple weeks. Wheat and barley are heading; if the drier weather keeps up, it will lower the risk for Fusarium.—Kelly Nichols, Montgomery Co.

Northern Maryland

Rain has been hard to come by with only about 1” of accumulated rain in the last 4 weeks. Corn and soybean planting has been in rolling for 2.5 weeks now, with a very large majority of it within the last week to 10 days or so. Small grains generally look very good, pastures and hay fields have also enjoyed the cooler than normal March and April. Wheat is anywhere from boot to head emergence. After a soggy start to April, we could use some rain.—Andy Kness, Harford Co.

Upper and Mid Shore

The rains from early in the month are now just a memory, with clear skies and no significant rainfall since. Dust clouds swirling on the horizon are a clear sign that #Plant2024 is underway. Farmers are terminating their cover crops and tilling the soil, readying it for planting. This year, we’re running a week or two ahead of last year’s schedule, raising hopes for another bumper crop. Small grains are currently heading, with some currently flowering.—Dwayne Joseph, Kent Co.

Lower Shore

After a rainy stretch, we’ve gotten some dry weather this past week. About half or more of cover crop acreage has been terminated. Some ground is being tilled, while the majority will be planted no-till. Corn is currently being planted. Wheat is looking very good. If wheat varieties are susceptible to Fusarium Head Blight and if the wheat is flowering, fungicides should be considered. The first cutting of hay has started.—Sarah Hirsh, Somerset Co.

Southern Maryland

Field conditions are a mixed bag. Areas to the north have turned dry in the last week. Areas to the south received more rain delaying field operations. In drier areas, soil has become hard and compacted, aggravated by wet conditions over the winter. This is a year where big differences in soil conditions can be observed between no-till and tilled fields. Planters have been rolling for the last two weeks with conditions mostly ideal for planting. Corn emergence looks good so far. Slugs were a concern early, but drier weather has helped with that issue. We have many acres of early planted soybeans again this year. Burndown programs have been challenged this year with many escapes of annual ryegrass. Wheat is headed and beginning to flower now. We are observing some yellowing of the flag leaf and leaf below the flag leaf across many fields that showed up in the last 10 days. We are working to determine the exact cause, but believe it related to environmental conditions with perhaps some virus issues like BYDV as well. A lot of good dry hay has been made in the last two weeks. On the fruit and vegetable front, plasticulture strawberries look very good and are ripening now. All of our main season vegetable crops are preparing to go in the ground this week. High tunnel crops are coming off now.—Ben Beale, St. Mary’s Co.

*Regions (counties):
Western: Garrett, Allegany, Washington. Central: Frederick, Montgomery, Howard. Northern: Harford, Baltimore, Carroll. Upper & Mid Shore: Cecil, Kent, Caroline, Queen Anne, Talbot. Lower Shore: Dorchester, Somerset, Wicomico. Southern: St. Mary’s, Anne Arundel, Charles, Calvert, Prince George’s

Wheat Leaf Tip Necrosis Showing in Many Wheat Fields

Andrew Kness, Senior Agriculture Agent | akness@umd.edu and Nidhi Rawat, Small Grains Pathologist
University of Maryland

Over the past couple of weeks we have gotten several questions about yellowing flag leaves on wheat. Generally these symptoms are appearing widespread in fields. To the best of our knowledge we can attribute this to leaf burn or leaf tip necrosis (LTN) (Figure 1). This disorder is often a response to cold injury or wind, but can also manifest as a result of heat and drought stress. We have had widespread hot and dry conditions for several weeks across Maryland, which can trigger these symptoms, especially on lighter soils. These symptoms can also be intensified by specific leaf rust and stripe rust resistance genes and LTN severity can vary greatly between varieties. In any case, there is nothing you can do to remedy the situation.

Figure 1. Wheat leaves with symptoms of leaf tip necrosis. Note the dead tissue at the leaf tips.

Leaf tip necrosis may be confused with barley yellow dwarf virus (BYDV). BYDV is undoubtedly contributing to some of the symptoms in many of these fields, but it is probably not the sole factor causing these symptoms. LTN tends to cause death of the leaf tip resulting in necrotic brown tissue (Figure 1), whereas BYDV can cause a range of symptoms from yellowing of the leaf, which may or may not be accompanied with bronzing/purpling of the leaf tips (Figure 2). Notably with BYD, leaf tips do not die and become necrotic; whereas leaf tissue from LTN will become brown and dead starting at the leaf margins near the tip and work inward. Since BYDV is vectored by aphids, symptoms tend to be localized in hotspots in a field where aphids populations are high, whereas leaf burn and LTN more uniformly affect the entire field.

Figure 2. Symptoms of barley yellow dwarf virus. Leaf tips are yellow and purple/bronze but tissue is not dead.

Overview of Fungicides for Head Scab Control in Wheat

Andrew Kness, Senior Agriculture Agent | akness@umd.edu
University of Maryland Extension, Harford County

This article may come a little too late for some of you depending where you are in the state; but nevertheless, here is a review/reminder. As we get into May, wheat will begin flowering and we will have to consider fungicide applications to wheat to manage Fusarium head blight (FHB), also known as head scab. FHB is the most economically important disease of wheat, causing not only yield reductions, but more seriously, grain quality issues due to the production of the mycotoxin deoxynivalenol (DON), also called vomitoxin.

The pathogen that causes FHB, Fusarium graminearum, persists in wheat, small grain, and corn residue. It infects the wheat plant through the open flower, which is why flowering is such an important management timing for quality wheat production. Fusarium graminearum requires moist conditions and moderate temperatures (59-86 °F) to initiate infection. If these conditions are met during flowering, the pathogen will infect susceptible wheat varieties and cause disease.

Management of FHB requires a layered approach of IPM practices, with the major management practices being the selection of a good wheat variety and subsequent good planting and fertility practices, plus the use of a fungicide at flowering should the environmental conditions be conducive for FHB development. The wheatscab.psu.edu map can be helpful in predicting FHB risk to wheat around flowering.  Historically, this model has been over 70% effective at predicting FHB outbreaks and should be consulted when making fungicide decisions. If you decide to apply a fungicide to manage FHB, there are three important factors to consider: 1.) Timing, 2.) Application method, and 3.) Active ingredient.

As mentioned earlier, the pathogen can only infect wheat through the open flower, so you need to time your fungicide application as close to flowering, or Feekes Growth Stage 10.5.1, as possible (Figure 1). This growth stage is defined by the appearance of yellow anthers in the center of the wheat spike on at least 50% of the plants. Once this stage is reached, the application window is about 5-7 days. Some fungicide products are labelled for application as early as Feekes 10.3 (half head emergence); however, this timing is not as optimal as 10.5.1—so wait if you can.

wheat at start of anthesis
Figure 1. Wheat at Feekes 10.5.1, indicating proper fungicide timing for FHB management. Photo: A. Kness, Univ. of Maryland.

The second factor is application method. Most of our fungicides on wheat go on with a ground sprayer. For ground applications it is important to achieve good coverage of the wheat heads, not the foliage. To do this, spray volumes should be at least 15-20 gallons/acre and you should use bi-directional spray nozzles angled forward and backwards. This combination of spray volume and angled nozzles results in thorough coverage of the wheat heads. Aerial applications should be done at 5 gallons/acre for maximum coverage.

The final consideration is fungicide active ingredient. Triazole and HDMI fungicides work best on FHB. Products include: Prosaro Pro, Prosaro, Miravis Ace, Saphaerex, Proline, and Caramba; Folicur has less efficacy than the others and Tilt is no longer effective on FHB. An added benefit is that these products will also do a good job of keeping other fungal diseases at bay during grain fill. Do not apply any group 11 (Qoi/strobilurin) fungicides such as Aproach, Headline, or Quadris after heading as these products can actually increase DON levels in the grain.