Farmers May Fertilize Small Grains With Commercial Fertilizer Beginning February 15

Reposted from the Maryland Department of Agriculture

The Maryland Department of Agriculture today announced that farmers who planted small grains for harvest last fall may “top dress” these crops with commercial fertilizer in accordance with their nutrient management plans, beginning February 15, provided that crop and field conditions remain favorable.

University of Maryland researchers have determined that crop growth stages vary across the state. The Lower Eastern Shore of Maryland and Southern Maryland appear to have met the appropriate time to top-dress. However, the Maryland Department of Agriculture has given approval to all Maryland farmers to begin applying fertilizer to small grains, as long as crops have reached the “green-up” stage before applying fertilizer. The University recommends split applications of spring nitrogen with the first application occurring at “green-up” and the second application when the crops begin to joint. Check individual field conditions and avoid running heavy equipment across saturated soils.

The determination follows Maryland’s nutrient management regulations. As a reminder, manure may not be applied to fields until March 1.

For additional information on Maryland’s nutrient application requirements, contact the MDA’s Nutrient Management Program at 410-841-5959.

For a directory of University of Maryland Nutrient Management Planners, visit: https://extension.umd.edu/resource/ume-nutrient-management-advisors/.

Scout for Aphids in Small Grains

Kelly Hamby, Associate Professor and Extension Specialist, University of Maryland and
David Owens, Extension Entomologist, University of Delaware

Figure 1. Barley Yellow Dwarf patch in a field of malting barley, March 2023. Photo: David Owens, Univ. of Delaware.

Last season, aphids transmitted an unusual amount of barley yellow dwarf virus (BYDV) to wheat and barley across the Delmarva Peninsula. BYDV is particularly important when it infects plants in the fall. Fall BYDV infections can stunt plants (noticed as early as green-up, Figure 1) and cause more serious yield loss than spring infections. Our most common small grain aphid species are bird cherry oat aphid (Figure 2) and English grain aphid, although bird cherry oat aphid are associated with greater and more severe incidence of BYDV.

Figure 2. Bird cherry-oat aphids.

Historically, planting after the Hessian fly-free date (Table 1) reduced the likelihood of fall BYDV infection. However, fly-free dates were calculated more than 100 years ago, and it is now not uncommon for our first killing frosts to occur in late October or even November. Long falls with milder weather allow more time for aphids to colonize fields and potentially transmit the virus. Small grains varieties vary in their susceptibility to BYDV, and planting varieties with at least some tolerance can help. Unfortunately, resistant varieties are not available in barley. Finally, monitoring and managing the aphid vectors may be necessary.

Identifying bird cherry-oat aphid: A magnifying hand lens is required to identify aphids. Bird cherry-oat aphid ranges from orange green to olive green to greenish black. Wingless individuals typically have a reddish orange patch around the base of the cornicles (tail pipes). Winged individuals tend to be very dark. Their legs, cornicles, and antennae are similar in color to their bodies and medium in size.

Monitoring and thresholds: Typically, monitoring aphids in the fall and at green-up provides the best chance of identifying and mitigating BYDV risk. Scout ten locations per field avoiding field margins and look at 1 ft of row in each, making sure to look at the crown (at or below ground level), at the stem, and on the undersides of leaves. English grain aphids tend to feed on the uppermost portions of the plants while bird cherry oat aphids tend to cluster on the lower portions, especially in barley.

University extension threshold recommendations vary by region. In southern states, 6 aphids/row-ft is considered justification for a treatment in the fall. North Carolina uses a threshold of 20 aphids/row-ft where BYDV has been a problem and cold weather is not in the 7 day forecast. For other small grains, consider increasing the threshold to 25-50 aphids per foot of row.

In 2022, one of the malting barley fields sampled averaged 17 aphids per row-ft in early November. Because of unusually warm winter weather in which average temperatures were greater than 38 degrees, aphid populations peaked in one field at 235 aphids per row-ft that had averaged 1.8 per row-ft in November. This highlights the need to regularly monitor aphid populations during periods of mild weather.

Natural enemies: A number of natural enemies feed upon or parasitize aphids and they often do a good job keeping aphid populations down. One natural enemy per 50-100 aphids should be sufficient to control aphid populations. In addition, they are good at finding aphids even when their populations are low. Small wasps that develop within aphids leaving behind “mummy” aphids (Figure 3A), lady beetles, lacewing larvae (Figure 3B), and flower fly larvae (Figure 3C) are especially common aphid natural enemies. Insecticides will also kill these natural enemies.

Figure 3. Aphid natural enemies A) parasitoid wasp and golden or tan colored “mummy” aphids, B) lacewing larva eating aphids, C) flower fly larva eating aphids. Images: David Cappaert, Bugwood.org.

Insecticides: Seed treatments (e.g., Cruiser, Gaucho) provide some protection from fall aphids, but do not continue to provide protection into the spring and are not economic in years where aphids do not occur. Due to the differences in economics and BYDV susceptibility of malting barley varieties, seed treatments may be more useful than in feed barley or wheat. We generally recommend a foliar insecticide when aphid populations reach threshold. Small grain aphids are generally quite susceptible to insecticides. Pyrethroid products (e.g., Warrior) or a pyrethroid-neonicotinoid mix (e.g., Endigo, labeled for barley only) work well for aphid control.

 

Table 1. Hessian fly-free dates for Maryland and Delaware counties

State County Date
Maryland Allegany Sept. 27
Anne Arundel Oct. 7
Baltimore Oct. 2
Calvert Oct. 8
Caroline Oct. 7
Carroll Sept. 28
Cecil Oct. 3
Charles Oct. 8
Dorchester Oct. 9
Frederick Oct. 2
Garrett Sept. 20
Harford Oct. 1
Howard Oct. 2
Kent Oct. 6
Montgomery Oct. 4
Prince George’s Oct. 7
Queen Anne’s Oct. 7
Somerset Oct. 10
St. Mary’s Oct. 9
Talbot Oct. 8
Washington Oct. 1
Wicomico Oct. 10
Worcester Oct. 11
Delaware Kent Oct. 8
New Castle Oct. 3
Sussex Oct. 10

More information:

Kleczewski, N., Cissel, B., Whalen, J. 2016. Barley Yellow Dwarf Management in Small Grains. http://cdn.extension.udel.edu/wp-content/uploads/2015/10/14051904/BYDV-Final-Draft-9-12-16.pdf.

Flanders, K., Herbert, A., Buntin, D., Johnson, D., Bowen, K., Murphy, J. F., Chapin, J., Hagan, A. 2006. Barley Yellow Dwarf in Small Grains in the Southeast. https://entomology.ca.uky.edu/files/efpdf1/ef150.pdf.

Owens, D. and B. Cissel. Insect Control in Small Grains (for Grain only) – 2020. https://www.udel.edu/content/dam/udelImages/canr/pdfs/extension/sustainable-agriculture/pest-management/Insect_Control_in_Small_Grains_2020.pdf.

 

2023 Small Grain Variety Trials

Vijay Tiwari, Assistant Professor, Department of Plant Science and Landscape Architecture
University of Maryland, College Park

Results from the 2022/23 University of Maryland wheat and barley variety trials have been published. You can access the report by clicking the link.

Click here to view the report

For questions/comments, please email Dr. Vijay Tiwari at vktiwari@umd.edu. For more information on how to make the most of variety trial data, refer to our fact sheet: What do the Numbers Really Mean? Interpreting Variety Trial Results (FS-1119)

Wheat Quality Concern—Falling Numbers are Falling

Nicole Fiorellino, Extension Agronomist | nfiorell@umd.edu
University of Maryland, College Park

Figure 1. Extreme example of pre-harvest sprout in wheat. Image: Ohio State University.

2023 was shaping up to be a decent wheat season, with mild winter and minimal disease impacts this spring. Although some areas of the state were dry, there were some timely rains at the end of April to get the crop through the rest of the season. We sometimes forget that wheat thrives in much drier climates than the Northeast, and what seems dry to us was probably ideal for wheat.

As wheat harvest is currently underway in some areas of the state, the hopes of high yields and disease-free grain may now be riddled with an unseen quality blemish – falling falling numbers. Growers producing wheat for use in milling or baking are paying attention to quality measures such as falling numbers, or the activity of the alpha amylase enzyme in the grain stemming from pre-harvest sprouting. As grain begins sprouting within the head, prior to harvest, alpha amylase builds up and degrades starch, which decreases flour quality. To measure falling numbers, a slurry of grain meal and water is mixed and a plunger is dropped into the slurry, with the time measured for the plunger to drop through the slurry. High alpha amylase results in low starch, which thins the slurry and the plunger falls quicker, resulting in lower falling number measures. In short, low falling numbers equals bad quality wheat that is not suitable for milling or baking.

Causes of low falling numbers, similar to disease pressure, are somewhat out of a grower’s control and not very well understood. Some areas of the state received a respite from the dry conditions, in the form of a few days with a small amount of precipitation towards the end of June. While our corn crop happily received the moisture, this was enough rain in some areas to not only delay the beginning of wheat harvest but signal the wheat grain to break dormancy and begin to sprout. Low falling numbers may also be observed in grain that did not sprout due to a defect known as late maturity alpha amylase (LMA). This is the buildup of alpha amylase in the wheat grain triggered by cold stress during maturation. It is still unclear how to specifically define “cold stress” that causes LMA but it is yet another process that increases alpha amylase in the wheat grain, decreasing flour quality. In any given season, low falling numbers can be a result of either pre-harvest sprouting or LMA or even both conditions. Susceptibility to pre-harvest sprouting and LMA are genetically linked, but even with genetic resistance, the interaction between genetics and environmental conditions can still result in decreased falling numbers.

For the 2023 wheat crop, it is important to get wheat harvested as soon as possible. There is no way to correct for falling numbers now, but growers can make every effort to get wheat out of the field as quickly as possible to avoid exposure to additional precipitation events. While all hope is not lost and wheat with low quality can still be sold for feed, any potential premiums for producing high quality wheat will be lost. For future seasons, Maryland growers can make an effort to select early maturing wheat varieties, to hopefully expedite harvest in the spring. We know the down-season benefits of early wheat harvest, such as earlier planting and higher yields of double crop soybeans, and we are also aware of the potential risk of frost damage to early maturing wheat. However, early maturing wheat varieties may be a the best option to mitigate quality issues. While your premium for 2023 may be lost, you should begin discussing your 2024 wheat crop with your crop insurance agent now, especially if you are planning to grow high quality wheat for milling or baking. There may be coverage options available to protect you from lost premiums due to poor falling numbers, for example, so now is the time to plan accordingly for 2024.

2023 Small Grain Field Day

wheat field

Date: May 23, 2023
Time: 3pm
Location: Wye Research and Education Center
211 Farm Lane, Queenstown, MD 21658

Registration link: http://bit.ly/smallgrain23

The program will start at the seed building and proceed to the fields. We will hear an update on the Agronomy degree program within the Department of Plant Science and Landscape Architecture, including highlights from the first semester teaching AGST401: Tractor and Equipment Operation, Safety and Maintenance. We will showcase a commercial variety strip trial organized by the Maryland Crop Improvement Association (MCIA) and industry reps will be on hand to discuss their entries in the trials. Dr. Vijay Tiwari will discuss the small grain variety trials and his wheat breeding program, Dr. Nidhi Rawat will discuss her pathology work in barley and wheat, and Dr. Kurt Vollmer will update us on weed control in wheat.

Dinner will be served at 5pm, sponsored by Maryland Crop Improvement Association and others.For additional program information, contact Dr. Nicole Fiorellino at nfiorell@umd.edu or 443-446-4275.

Managing and Scouting Fields for Fusarium Head Blight

Alyssa Koehler, Extension Field Crop Pathologist | akoehler@udel.edu
University of Delaware

Wheat anthesis (flowering) is underway and will be continuing for the next 1-2 weeks across the region. Up until the rains this past weekend, we have been at low FHB risk. We are currently tracking as medium-high risk for very susceptible varieties and low-medium risk for varieties with some level of resistance (Figure 1). If you are planning for wheat fungicide application, scout frequently, looking for yellow anthers in the center of the wheat head (Figure 2) to signal that flowering has begun (Feekes 10.5.1). Depending on the weather, we can usually expect flowers to start showing up on wheat heads 3-5 days after full head emergence, with cool weather this can stretch this process out to 7-10 days. Anthers can remain attached after flowering, but become a pale white. For best mycotoxin (DON) control, it is better to be at flowering or a few days beyond than to spray too early when heads are not out yet (especially those secondary tillers). Fungicide products should be applied at the manufacturers recommended rate with nozzles angled 30-45° from horizontal (30 degrees is better than 45). Nozzles angled both forward and backward or twinjet nozzles that spray in two directions give better contact with the head and increase fungicide efficacy. For ground sprays, fungicides should be applied in at least 10-15 gallons of water per acre; aerial applications are recommended at 5 gallons per acre.

Figure 1. FHB Risk Model for very susceptible (top) and susceptible varieties (bottom) May 3, 2023 (wheatscab.psu.edu).
Figure 2. Wheat at flowering (Feekes 10.5.1) with yellow anthers visible 3-4 days after heads emerge.

Once wheat has flowered, symptoms of FHB are usually visible in 18-24 days, but cool weather can slow symptom development. Heads with FHB will have bleached florets or bleached sections of the head and may have pink growth on spikelets. Glume blotch may also be present, but typically has more of a grey appearance. You can follow these steps to assess the severity of FHB present in your field.

  1. For every 10 acres of field, randomly select one spot to survey.
  2. Keeping your line of sight above the wheat heads, walk 40-50 yards and randomly pick 10-20 heads to look at on the plant or detach and place into a bag. (Looking down may bias the heads you select).
  3. Once you have randomly collected the heads, rate the percent of each head with symptoms of FHB (bleaching or pink growth on spikelets). You can use the scale below to help calibrate your eye (next page).
  4. After you have recorded values for each head, determine the average percent FHB severity by dividing the sum of disease severities by the total number of heads collected. (Ex. You rate 10 heads with severity values: 0%, 10%, 30%, 0%, 0%, 20%, 10%, 0%, 0%, 0%. These add up to 70. 70/10 heads = 7% overall FHB severity). Higher levels of FHB are typically associated with elevated levels of DON and possible issues with yield and test weight. It is possible to have delayed or lower levels of symptoms and still have DON.
  5. Repeat this assessment as needed to get an overall rating for the field. Fields with greater than 10% FHB severity are at higher risk for yield losses or elevated DON. Fields with elevated DON should be harvested as early as possible and you may want to consider increasing combine fan speeds and shutter openings to reduce the amount of scabby kernels harvested. 

Small Grain Field Day

Join us for the 2022 Small Grain Field Day!

Date: Tuesday, May 24th, 2022

Time: 5PM – 7:30PM

Location: Wye Research and Education Center

211 Farm Lane, Queenstown, MD 21658

The program will start at the seed building and proceed to the fields.

Dr. Vijay Tiwari will discuss the small grain variety trials and his wheat breeding program. Dr. Nidi Rawat will then discuss fusarium research and prevention in wheat and barley. Next, we will have Dr. Alyssa Koeler touching on other small grain pathogens and Dr. Kurt Vollmer will bring us up to date on weed control in wheat. Finally, we will hear from Dr. Kelly Hamby on insect threats and control.

We also have a commercial variety strip trial organized by the Maryland Crop Improvement Association (MCIA) and industry reps will be on hand to discuss their entries.

Dinner will be served at 6:30, sponsored by Nagel Farm Service.

For more information and to registergo.umd.edu/smallgrain22

You can also contact Taylor Robinson at 443-446-4267 or taylormr@umd.edu.

For additional program information, contact John Draper at jdraper@umd.edu or 410-827-7388.

Register For The 2022 Virtual Agronomy Meeting

10 a.m. – 2:30 p.m.

This meeting will cover timely topics related to corn, soybean, and small grain production in Maryland. Hear from University of Maryland and other regional experts covering topics, such as:

  • Weed management with a limited toolbox
  • Hedging your bets to maximize profitability of fungicides on corn and soybeans
  • Agriculture leasing and agriculture law update
  • Corn nitrogen use following cover crops
  • Soil fertility and 4R

This meeting satisfies credits for pesticide applicator and nutrient management voucher renewals.

Register online: https://go.umd.edu/virtualagronomymeeting

2021 Maryland Small Grain Variety Trials

Results from the University of Maryland Small Grain Variety Trials are in the tables below. To download a pdf copy of the report, click here or visit https://psla.umd.edu/extension/md-crops/small-grains-maryland.

For questions regarding the small grain trials, contact Dr. Vijay Tiwari (vktiwari@umd.edu) or Dr. Nidhi Rawat (nidhirwt@umd.edu).

If you’d like to learn more about how to interpret variety trial data, view our fact sheet by clicking here.

Click to Download The 2021 Small Grain Variety Trials

 

 

April IPM Insect Scouting Tips

Emily Zobel, Senior Agriculture Agent Associate | ezobel@umd.edu
University of Maryland Extension, Dorchester County

Alfalfa

Alfalfa weevils emerge and lay eggs in alfalfa stems in Mid-April. The larvae are yellowish-green with blackheads. The easiest way to scout for this pest is to randomly collect 30 stems from the field and shake them into a bucket. The economic threshold for alfalfa weevil is determined based on the height of plants, the value of the forage, and the cost of insecticidal treatment. A threshold chart can be found on Penn State Extension website https://extension.psu.edu/alfalfa-weevil (Figure 1).

Figure 1. Economic threshold for Alfalfa Weevil. Source: Penn State University

Small Grain

Cereal leaf beetle adults become active in Maryland around mid-April. Adults will lay eggs and larvae will start feeding around the end of the month. Scouting should be done away from the field edge since they tend to clump in fields and near edges. Check tillers of 50-60 randomly selected plants per field and count the number of eggs and larvae. The economic threshold is reached when there is an average of one or more larvae on 25% of tillers. The populations can be spotty, so checking individual fields is often necessary.

Several species of aphids will start to appear in small grains and other spring crops in April, depending on the weather. The most common species in our area are English grain aphid, bird cherry-oat aphid, corn leaf aphid, and the greenbug. Springtime feeding damage can cause discoloration on the leaves and shriveled heads. To scout for aphids, examine one linear row-foot at ten sites within the field. The economic threshold for aphids in wheat in pre-heading stages varies based on the aphid species present. Still, the general rule is treatment is recommended if there is an average of 150 aphids per linear foot of row, with no natural enemies present. For information about species identification and thresholds, check out the “Early Aphid Occurrences: a Possible Result of Warmer Winter Temperatures” article on the Maryland Agronomy News Blog, or contact your local Extension agent.