Mild Winters Favor Greenbug Aphids and Winter Grain Mite in Small Grains and Orchardgrass

Kelly Hamby, Terry Patton, and Galen Dively
Department of Entomology, University of Maryland College Park

Summary. Weather stations in Baltimore, MD recorded the 3rd warmest winter on record in 81 years from Dec 2019 to February 2020, with 10% of our 30 year average snowfall (NOAA National Climate Report). Insects that overwinter as immatures or adults in above-ground protected areas are typically favored by mild winters, especially species that are not cold-hardy because much of the population would typically die during the winter. However, the lack of snowfall can also reduce overwintering survival because snow can insulate against freezing temperatures. Mild winter conditions favor green bug aphids and winter grain mite outbreaks in small grains and orchardgrass, and these pest populations can build rapidly. Fortunately, mild winters also favor many beneficial natural enemies. Greenbug aphid outbreaks have been observed in central Maryland orchardgrass (see Figure 1), and greenbugs have also been observed in Delaware. Overall, aphid populations have been spotty in Delaware and promising natural enemy activity has been observed (UD Weekly Crop Update, March 20). However, close surveillance is necessary when greenbug is the predominate species because greenbug injects toxic saliva during feeding and can be very destructive. It is important to carefully scout your fields for aphids multiple times to determine whether populations are building or crashing on your farm. Management interventions may be necessary to prevent economic losses. Winter grain mites may also be a problem this year and scouting close to the soil surface is necessary to catch this issue in a timely manner.

Figure 1. Heavy aphid populations have been observed in orchardgrass in central Maryland.
Figure 3. Aphid damage to orchardgrass in central Maryland.

Cereal Aphids and Greenbugs. Multiple species of aphid occur in Maryland small grains and orchardgrass (see Figure 2) and aphids can vector barley yellow dwarf virus. Bird-cherry oat aphids vector the most severe strain and may need to be managed in the fall to prevent damage from barley yellow dwarf, especially in intensive management wheat. Although the direct damage from aphid feeding is generally similar across species, it is especially important to record species if greenbugs are present. Greenbug saliva contains enzymes that break down cell walls, so their feeding is most damaging. They initially cause spotting on the leaf followed by discoloration and eventual leaf and root death if feeding continues. Grain cultivars vary in their tolerance for greenbug damage. One of the first noticeable symptoms of aphid outbreaks are circular yellow to brown spots with dead plants in the center (see Figure 3); however, aphid damage may be confused with moisture stress and/or nitrogen deficiency so make sure to scout for aphids especially in areas that are showing stress symptoms. Scout a minimum of 1 linear row foot in 10 sites, the more row feet and locations the better, and estimate the number of aphids per foot of row. The rule of thumb treatment threshold for small grains is to treat if counts exceed 150 per linear foot throughout most of the field, with few natural enemies detected (e.g., mummy aphids, lady beetles, fungal infections). One natural enemy to every 50 to 100 aphids can be enough to control the population. This threshold may be lower if greenbugs are the predominant aphid and greenbug populations should be carefully monitored. Foliar insecticides including pyrethroids (Group 3A), neonicotinoids (Group 4A), and organophosphates (Group 1B) can be used to control aphids.

Figure 2. Common cereal aphids. Notice color and length of antennae and cornicles (tail pipes). Greenbugs are light green with a dark green stripe, with black tips of the legs, cornicles, and antennae. Photos: Various Extension websites.

Winter Grain Mite. Winter grain mites are a cool season pest of small grains and orchardgrass that cause a silvery leaf discoloration from feeding damage that punctures individual plant cells. Feeding can also stunt plants. Winter mites have a dark brown to black body with bright reddish-orange legs (see Figure 4). Somewhat uniquely, their anal opening is on the upper surface and can appear as a tan to orange spot that is more visible under magnification. Two generations of winter grain mite occur per year and are active from the fall to early summer. They oversummer in the egg stage, with the first generation hatching around October and adult populations peaking in December or January. The second generation peaks from March to April and produces the oversummering eggs. Because spring eggs result in fall populations, rotating the crop away from grasses and managing wild grasses around field edges can be helpful to reduce populations. Adult activity occurs when temperatures are between 40 and 75°F, and they prefer cool, cloudy calm weather. Therefore, winter grain mites are easier to see during these conditions, and more likely to be higher on the plant during the early morning or late evening. If you are scouting on a hot, dry day or in the middle of the day, you should check under residue where the soil is moist, and may need to dig 4 or 5 inches into the soil to find the mites. Winter grain mite does not typically cause economic damage, and no thresholds have been developed. If large portions of a field show symptoms and mites are present, treatment may be warranted. No products are specifically labeled for winter grain mite; however, products labeled for brown mite such as dimethoate (Group 1B, in wheat only) are likely to be effective. Warrior II (pyrethroid, Group 3A) may also provide suppression.

Figure 4. Winter grain mite adult.

References and Useful Extension Articles:

Kansas State University Wheat Pests, Winter Grain Mite, https://entomology.k-state.edu/extension/insect-information/crop-pests/wheat/winter-grain-mite.html

NOAA National Climate Report Supplemental Material, https://www.ncdc.noaa.gov/sotc/national/202002/

Oklahoma State World of Wheat Blog, Winter grain mites in northcentral OK, https://osuwheat.com/2015/01/06/winter-grain-mites-in-northcentral-ok/

University of Delaware Weekly Crop Update March 20,2020. Agronomic Crop Insect Scouting, https://sites.udel.edu/weeklycropupdate/?p=14510

University of Delaware Fact Sheets and Publications, Winter Grain Mite Management in Small Grains, https://www.udel.edu/academics/colleges/canr/cooperative-extension/fact-sheets/winter-grain-mite/

Virginia Tech Insect Control in Field Crops, ENTO-335C, https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/456/456-016/ENTO-335C.pdf

 

 

Managing Fusarium Head Blight

Dr. Alyssa Koehler, Extension Field Crops Pathologist
University of Delaware

With the mild winter, wheat and barley are moving right along. Planting behind corn is common in our region, but this maintains inoculum for Fusarium Head Blight (FHB). Fusarium species that cause FHB can infect both corn and small grains. Walking through fields with corn stubble, you may see orange growth on old debris (Figure 1). Wet spring conditions favor fungal sporulation that can lead to infected wheat heads. As the pathogen grows on debris, spores are released that can be rain dispersed or moved through air currents. As the grain is flowering, spores land on the head or anthers, colonize these tissues, and move into the grain head. Once inside the grain, water and nutrient movement is disrupted, which results in the bleached florets we associate with FHB (Figure 2). Shriveled and wilted “tombstone” kernels can reduce yield and result in grain contaminated with mycotoxins. Deoxynivalenol (DON), also referred to as vomitoxin, is a health hazard to humans and animals. Wheat heads colonized later in development may not show dramatic symptoms, but can still have elevated DON.

Figure 1 (left). Corn stubble with Fusarium sporulation that can contribute to FHB in wheat. Figure 2 (right). Wheat head showing bleached florets from Fusarium Head Blight.

As we approach heading and begin to think about in-season disease management strategies, a well-timed fungicide application can help to reduce disease severity and DON levels. It is important to remember that fungicides can help to reduce disease levels and DON (traditionally around 50% reduction on a susceptible variety), but they do not eliminate FHB or DON. To try to maximize the efficacy of fungicides, it is important to apply at the correct timing. Fungicides for FHB are most effective when applied during flowering in wheat and at head emergence in barley. The Fusarium Risk Assessment Tool (www.wheatscab.psu.edu) is a forecasting model that uses current and predicted weather forecasts to predict FHB risk. The model is currently being configured for this season and should be accessible at the link above by the end of the first week of April. Historically about 70% accurate, this tool aids in assessing FHB risk as wheat approaches flowering and fungicide application decisions are made. The pathogen that causes FHB infects through the flower and rainfall 7 to 10 days prior to flower favors spore production and increases risk of infection. Optimal wheat fungicide application is at early flowering (10.5.1) to about 5 days after. Although new products like Miravis Ace can be applied earlier, it is still best to wait for main tillers to be at 10.5.1 or a few days beyond so that secondary tillers have a greater chance of being at 10.3-10.5.1. If you spray too early, heads that have not emerged will not be protected by the fungicide application. When wheat heads begin to flower, look for yellow anthers in the middle of the wheat head. When at least 50% of main stems are flowering, you will want to initiate fungicide applications. As the flowering period continues, anthers will emerge from the top and then the bottom of the wheat heads. Anthers can stay attached after flowering but usually become a pale white (Figure 3, next page). Triazole (FRAC group 3) fungicides that are effective on FHB include Caramba (metconazole), Proline (prothioconazole), and Prosaro (prothioconazole + tebuconazole). Miravis Ace (propiconazole + pydiflumetofen) offers a triazole + SDHI, FRAC group 7. As a reminder, fungicides containing strobilurins (QoI’s, FRAC 11) should not be used past heading because these fungicides can result in elevated levels of DON. Flat fan nozzles pointed 90° down are great at covering foliage but they do not provide good coverage on heads, which is the target for FHB management. Nozzles that are angled forward 30-45° down from horizontal (30 degrees is better than 45) or dual nozzles angled both forward and backward give better contact with the head and increase fungicide efficacy. For ground sprays, fungicides should be applied in at least 10 gallons of water per acre.

Figure 3. From left to right: Feekes 10.3, Anthesis; Feekes 10.5.1 (yellow anthers beginning flowering); 4 days after anthesis (white anthers post flowering). Image: A. Koehler, Univ. of Delaware.

Thinking beyond this season, an integrated approach can improve management of FHB and help to keep DON levels low. In your field rotation plan, avoiding planting small grains into corn residue will help to reduce the amount of initial inoculum in your field. If you have soybean fields that can be harvested early enough for a timely wheat planting, this rotation helps to break up Fusarium inoculum. In addition to rotation considerations, seed selection is another important piece of FHB management in wheat. There is no complete host resistance against FHB, but you can select wheat varieties with partial resistance. The University of Maryland sets up a misted nursery to compare FHB index and DON levels across local wheat varieties to aid in variety selection decisions. Results from 2019 can be found at https://scabusa.org/pdfs/UMD_Misted-Nursery_Factsheet-2019.pdf. Remember that these trials are conducted under extreme disease pressure and you want to look at relative DON performance. Unfortunately, barley does not have any resistance to FHB. In UMD’s 2019 trial, Calypso had the lowest DON content in local barley varieties tested.

 

February WASDE

Dale Johnson, Farm Management Specialist
University of Maryland

Information from USDA WASDE report

Attached is a summary for the February WASDE published Tuesday. There was a 50 million bushel increase in the estimate of corn use for ethanol but this increase was offset by a 50 million decrease in the estimate of corn exports and so there was no change in supply, demand or ending stocks.

There was a significant 50 million bushel increase in the estimate for soybean exports. With all other supply and demand factors unchanged this decreased the stocks to use ratio from 11.9% to 10.5%. However, this was anticipated so there was no significant increase in Soybean futures on Tuesday.

There was a 25 million bushel increase in the estimates for wheat exports with all other supply and demand factors unchanged. However with the large ending stocks of wheat, this change was relatively insignificant.

2020 February WASDE

 

Call for Farmer participants in organic grain transitions project

Researchers at the University of Maryland are looking for farmers interested in partnering with them on a project to help develop strategies for transitioning to organic grain production. Please see the attached flier for details. Contact Dr. Ray Weil for additional information (rweil@umd.edu).

Organic Transitions1page announcement Jan2019

2020 Grain Marketing Workshop

Friday January 10, 2020 from 8:00am – 11:30am

This breakfast meeting will include speakers on various topics in grain marketing.  Come have breakfast and discuss this year’s strategies for marketing your grain. Speakers include marketing specialists, traders and more.  Topics include local and national grain outlook for 2020, tax considerations, crop insurance and the farm bill.

Locations

In person:

  • Chesapeake College, Wye Mills, MD Higher Education Center HES-110. Contact Shannon Dill, sdill@umd.edu or call 410-822-1244.

Broadcast to:

  • Charles County Extension, 9501 Crain Hwy, Bel Alton, MD 20611. Contact Alan Leslie, aleslie@umd.edu or call (301) 934-5403
  • Harford County Extension, 3525 Conowingo Rd., Suite 600, Street, MD 21154. Contact Andy Kness, akness@umd.edu or call (410) 638-3255
  • Somerset County Extension Office, 30730 Park Dr, Princess Anne, MD 21853. Contact: Sarah Hirsh, shirsh@umd.edu or call (410) 651-1350

November WASDE

Dale Johnson, Farm Management Specialist
University of Maryland

Information from USDA November WASDE report

Attached is the summary for the November WASDE published on November 8. After months of volatile WASDE estimates caused by weather and political events, the changes in estimates for the November WASDE are fairly small. Corn yield/acre estimate was down 1.4 bushels/acre to 167 bushels/acre. But the estimates for all areas of demand were also down slightly. The net effect is ending stocks down 19 million bushel to 1,910 million bushel and a stocks to use ratio of 13.7%.

Production and supply estimates for Soybeans were unchanged. Crushings  were down slightly which increase the ending stocks 15 million bushel and a modest increase in the stocks to use ratio to 11.9%.

There were only slight changes in Wheat estimates.

October WASDE

Dale Johnson, Farm Management Specialist
University of Maryland

Information from USDA October WASDE report

Attached is the summary for the September World Agricultural Supply and Demand Estimates (WASDE) that was published on October 10. Corn harvested acres and yields were slightly adjusted. The estimate for beginning stocks were down 331 million bushels. Estimate for total use was down 90 million bushel. Other minor changes result in an estimate of endings stock 261 million bushel lower and a decrease in the estimate of Ending Stocks to Use Ratio from 15.5% in September to 13.8% in October.

Soybean harvested acres estimate decreased from 75.9 to 75.6 million acres. Yield estimate was adjusted up 1 bushel per acre. Beginning stock estimate was adjusted down and ending stocks estimate was down 180 million bushel, which significantly decreased the stocks-to-use ratio from 15.9% to 11.4%. In June, the estimated Stocks to Use Ratio was 24.9% and has been decreasing every month. But market prices have not responded significantly because of the uncertainty in the soybean market caused by the trade war.

There were only slight changes in Wheat estimates.

September WASDE

Dale Johnson, Farm Management Specialist
University of Maryland

Information from USDA September WASDE report

Attached is the summary for the September World Agricultural Supply and Demand Estimates (WASDE) that was published on September 12. Corn harvested acre estimate was unchanged but yield estimate was adjusted down 1.3 bushel per acre to 168. Other estimate adjustments were insignificant.

Soybean harvested acres estimate was unchanged but yield estimate was adjusted down 0.6 bushels per acre. Beginning stock estimate was adjusted down and ending stocks estimate was down a significant 115 million bushel which significantly decreased the stocks-to-use ration from 18.8% to 15.9% which gave a bump to market prices. Today, Friday 13, China announced exemptions for soybean and pork tariffs which should further help our situation. 

There were no changes in wheat estimates.

September 2019 WASDE table
Download the table here: September 2019 WASDE

Interseeding Cover Crops into Double-Crop Soybeans – Initial Findings

1,2Cara Peterson, 2Steven Mirsky, 1Kate Tully, 1,2Victoria Ackroyd
1Department of Plant Science and Landscape Architecture, University of Maryland
2United States Department of Agriculture, Agricultural Research Service, Beltsville

The mid-Atlantic region has the highest percentage of arable acreage in cover crops in the United States, with some reports placing Maryland and Delaware as the two states with the highest percentage of total cropland planted with cover crops (Wade et al., 2015; Hamilton et al., 2017). However, the majority of producers in the region are only using grass cover crops, since legumes require earlier planting dates in order to over-winter (Mirsky et al., 2011; Clark, 2012). Farmers in this region have success with legume cover crops when planting them after wheat harvest or frost-seeding in the spring. However, most mid-Atlantic crop rotations include double-crop soybeans planted after wheat, which limits opportunities for establishing a legume cover crop. Low legume adoption is particularly problematic as farmers could use this cover crop before corn to maximize the opportunity for nitrogen fixation benefits.

cover crop rotation schematic
Figure 1. (Top) A typical mid-Atlantic crop rotation, with double-crop soybeans in the field at the pivotal points for establishing a successful legume cover crop. (Bottom) Proposed crop rotation scheme for interseeding a cover crop between 30-inch soybeans. The cover crop over-winters and is terminated before corn planting in the spring.

Some farmers interseed cover crops into growing cash crops to overcome this timing challenge. Current options for planting cover crops into standing corn and soybean include both aerial broadcasting via airplane and adapted high-boy sprayers. However, these two techniques often result in poor establishment due to low seed-to-soil contact and seed predation by rodents and birds (Hively et al., 2001; Baker and Griffis, 2009; Wilson et al., 2013).

Interseeder
Figure 2. Interseeding cover crops with three planting units between 30-inch soybean rows.

To address the issue of planting cover crops into standing cash crops, our mid-Atlantic team ran numerous trials of an InterSeeder grain drill (InterSeeder Technologies, LLC; Fig. 2). Engineered by the Pennsylvania State University, this drill plants three rows of cover crops between 30-inch rows of standing cash crops. Field trials of this InterSeeder have been conducted in corn, as well as full-season soybeans, at various sites in the region with mixed results (Curran et al., 2018; Wallace et al. 2017). In Maryland, interseeding into full-season corn was moderately successful, whereas cover crops did not perform well in full season beans. However, exploratory research in Maryland identified wide-row double crop soybeans as a viable option for interseeding. The success of seeding grass-legume mixtures into 30-inch double-crop soybeans has led to an expanded on-station research program.

New Field Trials. Field trials with five different interseeded cover crop treatments were conducted to determine the optimal legume cover crop species to interseed in mixture with cereal rye and if interseeding a cover crop mixture affected wide-row double crop soybean yields. The five different cover crop treatments included: cereal rye alone, cereal rye independently mixed with four different legumes (hairy vetch, crimson clover, red clover, and winter pea), and a no cover crop control (Table 1).

Cover Crop Seeding Rates
Table 1. Interseeding Trial Cover Crop Seeding Rates

Double-crop soybeans planted in June were then interseeded with the cover crop treatments in early September 2017 and late August 2018. The double-crop soybeans were harvested in November for 2017 and later in 2018 (December) due to wet field conditions. The interseeded cover crop treatments grew throughout the winter and were terminated with herbicides in April 2017 and 2018 before planting corn.

In an ideal interseeding scenario, the cover crop is planted as the double-crop soybeans are beginning to reach full canopy in early September. That way, the cover crops only have to survive a few weeks under the low light conditions of a soybean canopy until leaf drop. Once the soybean canopy is gone, the cover crops continue to grow but do not interfere with soybean harvest.

Insights from Interseeding Trials

  • Cereal rye + crimson clover produced the highest average cover crop biomass. The cereal rye + crimson clover fall 2017 seeding produced an average of 4,980 lbs per acre of biomass while the 2018 seeding produced 3,950 lbs per acre by the spring of 2019. Cereal rye + hairy vetch and cereal rye + winter pea reached similar levels of biomass in two out of the three field sites where the cover crops survived under the soybean canopy.
  • Interseeding did not decrease yield. There was no pattern of soybean yield differences between the 30-inch wide row double-crop soybeans that had or hadn’t been interseeded. Likewise, there were very minimal differences in soybean yields between the cover crop treatments.
  • Interseeding did not affect soybean grain quality. Green cover crop plant material was not found in any soybean grain subsampling. Moisture levels remained consistent, with very slight variance across the field as expected in a normal cropping system.
  • Row orientation matters. Out of the five trial sites, two of the cover crop plantings did not survive under the soybean canopy. Interestingly, the three field sites with strong cover crop survival rates had rows oriented in roughly the same direction: East-West or Southeast-Northwest. The two field sites where the cover crops sprouted but did not survive under the soybean canopy in the fall were on a perpendicular row orientation of Northeast-Southwest. 

Row Spacing Considerations. The InterSeeder requires a 30-inch row spacing, while most double-crop soybean fields are planted in narrower rows of 15 inches or less. To account for the differing production practices, these field trials also included simple yield comparisons of 30- and 15-inch row double-crop soybeans. In the row spacing (15- vs 30-inches) trial, results were mixed. There was a yield penalty for wide row spacing in 2017, but not in 2018.

While the benefits of narrow row spacing have been well documented in full season beans, less is known about the potential advantages in double crop soybeans. We speculate that optimal production years enhance the effect of row spacing. For example, 2017 was a better soybean year compared to 2018 across the mid-Atlantic region. Higher levels of precipitation in 2018 than 2017 could have damaged yields. Previous research indicates that in lower yield years or for late-planted soybeans, the benefit of planting in 15 inch rows over 30 inch rows is lost (Alessi and Power, 1982; Hodges et al., 1983; Boquet, 1990; Weaver et al., 1990, Oplinger et al., 1992; Pederson and Lauer, 2003, Whaley et al., 2015).

Future Research. Nitrogen content analysis of the interseeded cover crop biomass is currently underway. Next, the research team will analyze how the following year’s corn crop responded to the interseeded cover crop mixtures.

References

Alessi, J., and J.F.  Power. 1982. Effects of plant and row spacing on dryland soybean yield and water-use efficiency. Agronomy Journal 74:851–854. D.o.i.:10.2134/agronj1982.00021962007400050019x

Baker, J. M., and T. J. Griffis. 2009. Evaluating the potential use of winter cover crops in corn-soybean systems for sustainable co-production of food and  fuel. Agricultural and Forest Meteorology, 149(12), 2120–2132. D.o.i.:10.1016 j.agrformet.2009.05.017

Boquet, D. J. 1990. Plant population density and row spacing effects on soybean at post-optimal planting dates. Agronomy. J.: 59–64. D.o.i:10.2134/agronj2009.0219.

Clark, A. (Ed.). 2012. Managing cover crops profitably (Third ed.). College Park, MD: Sustainable Agriculture Research and Education.

Curran, W.S., R.J. Hoover, S.B. Mirsky, G.W. Roth, M.R. Ryan, V.J. Ackroyd, J.M. Wallace, M.A. Dempsey and C.J. Pelzer. 2018. Evaluation of cover crops drill interseeded into corn across the mid-Atlantic region. Agronomy Journal 110, 435–443. D.o.i.:10.2134/agronj2017.07.0395

Fisher, K. A., B. Momen,, and R.J. Kratochvil. 2011. Is broadcasting seed an effective winter cover crop planting method? Agronomy Journal, 103(2), 472–478. D.o.i.:10.2134/agronj2010.0318

Hively, W.D. and W.J. Cox. 2001. Interseeding cover crops into soybean and subsequent corn yields. Agronomy. J. 93:308-313. D.o.i.:10.2134/agronj2001.932308x

Hodges, H.F., F.D. Whisler, N.W. Buehrig, R.E. Coast, J. Mcmillian, N.C. Edwards, and C. Hovermale. 1984. The Effect of Planting Date Row Spacing and Variety on Soybean Yield in Mississippi (Bulletin 912). Report prepared for the Mississippi Agricultural and Forestry Experiment Station.

Hamilton, A. V., D.A. Mortensen and M.K. Allen. 2017. The state of the cover crop nation and how to set realistic future goals for the popular conservation practice. Journal of Soil and Water Conservation. 72(5), 111-115A. DOI: 10.2489/jswc.72.5.111A

Mirsky, S.B., W.S. Curran, D.A. Mortensen, D.L. Shumway, and M.R. Ryan. 2011. Timing of cover crop management effects on weed suppression in no-till planted soybean using a roller-crimper. Weed Science 59:380–389

Oplinger, E.S. and B.D. Philbrook. 1992. Soybean planting date, row width, and seeding rate response in three tillage systems. Journal of Production Agriculture. 5: 94-99. DOI:10.2134/jpa1992.0094

Pedersen, P. and J.G. Lauer. 2004. Soybean growth and development response to rotation sequence and tillage system. Agronomy Journal 96(4), 1005–1012. D.o.i.:10.2134/agronj2004.1005

Wade, T., R. Claassen and S. Wallander. 2015. Conservation-Practice Adoption Rates Vary Widely by Crop and Region, EIB-147, U.S. Department of Agriculture, Economic Research Service. Available at https://www.ers.usda.gov/webdocs/publications/44027/56332_eib147.pdf?v=42403

Wallace, J.M., W. S. Curran, S. B. Mirsky, M.R. Ryan. 2017. Tolerance of interseeded annual ryegrass and red clover cover crops to residual herbicides in mid-Atlantic corn cropping systems,” Weed Technology, 31(5), 641-650.

Weaver, D.B., R.L. Akridge, and C.A. Thomas, C.A. 1991. Growth habit, planting date, and row-spacing effects on late-planted soybean. Crop Science (31) 805-810

Whaley, C., J. Adkins and P. Sylvester. 2015. Final report to Delaware soybean board: Evaluating the response of full season and double-cropped soybeans in narrow and wide rows to various soil moisture levels.

Wilson, M. L., J.M. Baker, and D.L. Allan. 2013. Factors affecting successful establishment of aerially seeded winter rye. Agronomy Journal, 105(6), 1868–1877.

 

Wheat Variety Selections—An Important Factor For Managing Head Blight

Andrew Kness, Agriculture Agent
University of Maryland Extension, Harford County

Compared to the 2018 wheat crop, 2019 was a much better year for Fusarium head blight (FHB, also known as head scab). Growing quality wheat in Maryland starts with proper variety selection. As you look ahead to the 2020 wheat crop, select wheat varieties that have good FHB ratings. There are no varieties with complete resistance to head scab; only varying degrees of susceptibility. Nevertheless, planting a somewhat resistant variety will go a long way in managing FHB and keeping vomitoxin levels (DON) lower in your grain compared to a susceptible variety.

To aid in your selection of wheat varieties, the University of Maryland screens several wheat varieties for their resistance to Fusarium graminearim, the causal agent of FHB. The results from the 2019 trials can be found here.

Additional considerations for FHB management include:

  • Planting behind soybeans rather than corn or other small grains. The FHB pathogen survives on residue of corn, wheat, barley, oats, and other grasses; however, it does not persist on soybean residue.
  • If planting into corn residue, consider tillage if it is an option for your farm. Sizing and burying corn residue will accelerate its decomposition and reduce the FHB pathogen survival.
  • Fungicides in spring 2020. Please note that fall fungicide applications do not have any effect on managing FHB. More information will be covered concerning fungicide recommendations in the spring, or read this article from earlier this year.