Category: Wheat

Barley Yellow Dwarf Symptoms and Management

Nidhi Rawat, Assistant Professor, University of Maryland

Barley Yellow Dwarf is an economically important viral disease of small grains: wheat, barley, oats, and triticale. The yield losses may vary year to year, and may range from 5 to 25 percent, depending upon the weather conditions. Mild winters favor buildup of large aphid populations in early-planted wheat. The causal organism is Barley Yellow Dwarf Virus (BYDV), a Luteovirus transmitted by aphids.

Continue reading Barley Yellow Dwarf Symptoms and Management

FHB Update – May 16, 2017

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

We are through flowering in Delaware and Maryland wheat. Growers should assess wheat for FHB severity approximately 18-24 days after flowering or fungicide application. Check one transect per 1-2 acres of field. At each transect, pick 25 heads without looking at the field. Mark the number of heads with FHB out of the total heads collected (FHB incidence). Fields with high levels of FHB incidence should be harvested with increased fan speeds to remove tombstones and grain stored separately from that harvested from cleaner fields. If possible, harvest fields early and dry to at least 15% moisture to prevent continued growth of the FHB fungus and potential mycotoxin production.

Fungicide Application Window for Fusarium Head Blight Suppression

Nathan Kleczewski, Field Crops Pathologist, University of Delaware

Heavy rains coupled with high winds made it difficult for growers in Delaware and Maryland to apply fungicides for Fusarium head blight (FHB) suppression.  There has been discussion about waiting until this current weather front passes to make applications. READ THE REST ON NATHAN’S BLOG POST:

http://extension.udel.edu/fieldcropdisease/2017/05/05/fungicide-application-window-for-fusarium-head-blight-suppression/

Fusarium Head Blight Risk – May 1, 2017

Nathan Kleczewski, Extension Field Crop Plant Pathologist, University of Delaware
Rain has pushed a large portion of the region into a severe level of risk for FHB if that wheat is currently flowering. Most of the wheat in S Delaware and S Maryland likely started to flower late last week and is at elevated risk for FHB, especially if a suceptible variety was planted. Growers with wheat flowering at this time are advised to make an application of a FHB fungicide (Caramba, Prosaro, Proline). Applications are most efficacious when applications occur from the start of flowering, through p days from the start of flowering. Apply in 5 gal/A air and 15 gal/A by ground, 300-350 um droplet size, with nozzles at least angled forwards 30 degrees. Wheat not yet flowering is not at risk. Continue to check your wheat and this page for updates.
Fusaruim Risk across the Mid Atlantic on May 1, 2017.

 

Late Season Fungicide Applications in Wheat

Nathan M. Kleczewski Ph.D., Extension Plant Pathologist, University of Delaware

I have had some questions regarding fungicides and application timings in wheat approaching flowering.   In particular, the question of efficacy on canopy and head diseases has come up in conversations.  The first thing to note is that the fungicides that are recommended for Fusarium Head Blight (FHB) suppression (Caramba, Prosaro, Proline) are effective in controlling foliar diseases.  Commonly encountered foliar diseases include Stagonospora leaf blotch, tan spot, powdery mildew, and the rusts.  However, it is important to understand that although these products are labeled for FHB, they are only effective if applied at the correct timing.  Applying these products before flowering will not result in FHB suppression.  This is because the FHB pathogen infects flowering grain heads (Figure 1). Continue reading Late Season Fungicide Applications in Wheat

Start Scouting Your Wheat

Wheat has headed out and started to flower in some locations on the Lower Eastern Shore of Maryland. It is a good time to scout if you are at flag (more than likely), boot (swelling before head emerges) or the head has fully emerged. A picture of flowering wheat from April 20, 2017 in Somerset County can be seen below. Look for the anthers to emerge from the center of the wheat head first. You may also read Nathan Kleczewski’s posts below on the risk of FHB right now and sign up for updates through the prediction center .

Continue reading Start Scouting Your Wheat

Stripe Rust Confirmed in Southern Delaware

Nathan M. Kleczewski, Extension Plant Pathologist, University of Delaware

We have confirmed stripe rust activity in Southern Delaware.  As the disease is active in S. DE, I suspect it also is present in parts of lower MD as well.  Most wheat in the southern part of the DE/MD region is about 7 days from flag leaf, and cooler weather is forecast over the next ten days.  Dynagro Shirley and Dynagro 9600 appear to be highly susceptible.  Barley is infected by a different species of the rust pathogen and is not at risk.

Growers should check their fields and consult their seed catalogues for stripe rust resistance ratings. Varieties with excellent or very good stripe rust ratings should not be at risk for significant damage from this disease.  Susceptible varieties may need a fungicide application if stripe rust is detected.  Group 3 (DMI) and premix fungicides containing a DMA (Stratego YLD, Quilt Xcel, Aproach Prima, Priaxor, etc.)  will provide excellent control.

***Stripe rust has also been confirmed in St Mary’s County, MD on Sisson variety wheat. An adjacent field of Jamestown wheat was still clean (4/12/2017) – Ben Beale, St Mary’s County Extension***

 

Early Aphid Occurrences: A Possible Result of Warmer Winter Temperatures

       Veronica Johnson, University of Maryland Department of Entomology

Aphids are small, early season pests that can occasionally reach damaging levels in small grain fields in Maryland. Strategies to control these insects should begin with correct pest identification and field scouting to determine infestation levels within a particular field.

Pest Identification:

Aphids are soft bodied, pear-shaped insects  with piercing-sucking mouthparts and a pair of “tailpipe-like” projections, or cornicles, emerging from their lower abdomen.  Adults can be winged or wingless, and the vast majority of aphids are female. A number of aphid species have been documented as either direct or indirect pests of wheat in Maryland. These include the bird cherry oat aphid, english grain aphid, corn leaf aphid, and the greenbug aphid. Continue reading Early Aphid Occurrences: A Possible Result of Warmer Winter Temperatures

Options for Freeze Damaged Wheat

Greg Halich, Extension Economist, University of Kentucky

 

A severe freeze in mid-March has likely damaged much of the wheat crop in Kentucky. The extent and severity of the damage will be better known one to two weeks after the freeze when baseline estimates can be made. Normally, producers would have three options to deal with wheat stands that have been damaged at this stage:
1) Stay the course, harvest the wheat and then double-crop soybeans.
2) Terminate the wheat stand and plant corn.
3) Terminate the wheat stand and plant full-season

Read the rest of the article on the University of Kentucky Grain Crops Blog:

https://graincrops.blogspot.com/2017/03/options-for-freeze-damaged-wheat-which.html