Author: agronomynews

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.

 

Monitoring Fields for Slug Damage

Jarrod Miller, Extension Educator, University of Maryland

As planters hit the fields it is a good time to review the conditions that may cause slug damage to your fields. Some factors that increase the incidence of slug damage include 1) fields with heavy residue (no till, cover crops, manure, ect), 2) mild winters that allow eggs to survive, 3) temperatures between 63 to 68F plus 75% soil moisture, and 4) growing conditions that slow crop development in the spring. Across Maryland, moisture contents will vary, but recent rainfall and cooler temperatures on the lower shore has produced soils close to field capacity.

Continue reading Monitoring Fields for Slug Damage

Diseases Affecting Soybean Production

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

Diseases significantly impact soybean production throughout the United States.  In Delaware, diseases such as Soybean Cyst Nematode, Root Knot Nematode, and stem canker can cause significant annual yield losses.  Plant pathologists throughout the United States collect disease loss data each year.  This data is compiled and published periodically.  Recently, summary data from 2010-2014 was published in Plant Health Progress.  What is the biggest message for you to keep in mind when reading this article?  Soybean cyst nematode reduces soybean diseases far more than any other plant disease.  Management of Soybean Cyst Nematode should be at the top of your list if you want to produce high yielding soybeans.  This means checking your fields for soybean cyst nematode populations over time, avoiding continuous soybean production, and planting soybeans with resistance to this nematode.

The most damaging diseases affecting soybean production in the United States.  From Allen et al 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

*Recall of Air-Purifying Respirators*

Amy E. Brown, Department of Entomology, University of Maryland

MSA recently determined that a small percentage of [its] Comfo Combination Cartridges, manufactured from September 1, 2016 through December 11, 2016, may not comply with the NIOSH required P100 filter minimum efficiency level of 99.97% for particulates. The affected cartridges types are listed below: Continue reading *Recall of Air-Purifying Respirators*

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***

 

Things to Consider When Using Dicamba Tolerant Soybeans

Matt Morris, Extension Educator, Frederick County (mjmorris@umd.edu)

Dicamba tolerant soybeans, marketed under the trade name Roundup Ready Xtend will be available to Maryland growers for the 2017 growing season. This line of soybeans will combine previous Roundup Ready technology with a tolerance to the herbicide dicamba. While this new dicamba tolerance may be useful in combatting certain tough-to-control weeds including marestail and palmer amaranth, caution needs to be taken when making applications of dicamba. Problems with dicamba applications may arise due to the sensitivity of certain crops to dicamba. Exposure can occur due to drift, volatility, or a non-target application. Below are some recommendations to consider when utilizing new dicamba tolerant technologies.

Know the location of sensitive crops:

Talk with your neighbors and know where crops such as tomatoes, grapes, alfalfa, and non-tolerant soybeans are located. This will aide in the decision to use dicamba near these crops, especially if a prevailing wind is headed their direction. In addition, buffer zones of 110’ (220’ if  a 22oz/ac rate is exceeded), will need to be maintained between dicamba application sites and sensitive crops. These two websites listed below contain a (incomplete) list of some sensitive crops in your area:(Link Here)

Dicamba type:

The only dicamba products that will be approved for in-crop use with Xtend soybeans will be XtendiMax from Monsanto, FeXapan from Dupont, and Engenia from BASF. These are lower volatility formulations than other dicamba products and are designed for the dicamba tolerant soybeans.

Rates:

Engenia – Dicamba tolerant soybeans – max of 12.8 fl oz/application and 51.2 oz/season.

FeXapan and XtendiMax – Dicamba tolerant soybeans – max of 44 fl oz/preplant application, 22 fl oz/postemergence application, and a max of 88 fl oz/season.

 Nozzle selection:

Engenia – Only TTI11004 and TTI11005 are currently approved.

FeXapan and XtendiMax – Apply large droplets with specific nozzles.  Do not use flat fan nozzles that product driftable fines.  Use TTI11004 or nozzles listed on the EPA-mandated product websites.

Spray adjuvants and water conditioning:

Ammonium sulfate (AMS) CANNOT be mixed with these new dicamba formulations. AMS is commonly used as a water conditioning agent for glyphosate applications. Adding AMS will increase volatility of the dicamba. Also, certain spray adjuvants and herbicide tank mix partners are not compatible with the new dicamba formulations. Always consult the label before mixing.

Recordkeeping:

Always keep records of where you’ve planted dicamba tolerant soybeans. This can help avoid costly misapplications to a crop that is not tolerant to dicamba. It will be extremely important to convey this information to custom application companies or employees on your farm.

Wind Speed, temperature, and temperature inversions:

When applying these new dicamba products the optimal wind speed is 3-5mph. Applications are prohibited when wind speeds are above 15mph; however, great caution and even stopping spraying when wind speeds are above 10mph would be ideal.

As temperature increases so does the volatility of dicamba. Caution should be used when applications are made in hot, humid weather.

Caution should also be taken when wind speeds are below 3mph as this could indicate the presence of a temperature inversion. Inversions are another cause of vapor drift. Other indicators of a temperature inversion include low hanging smoke or dust, morning fog or frost, clear and still nights with little to no cloud cover, and ground temperatures cooler than early morning air temperatures.

Multiple applications and weed height:

Multiple herbicide applications with the same mode of action within a single season selects for herbicide resistance. Avoid using dicamba on tolerant soybeans more than once in a season. If possible, a pre-emergence herbicide should be applied before or at planting. It is also important to remember that weeds should be targeted at 4” of height or less for successful control.

 Application Suggestions:

Keep ground speeds below 15 mph and nozzle pressures as low as possible to maintain the desired application rate. Boom height should be no more than 24” above the crop or weed canopy. If a weed is 4” tall, boom height should not exceed 28”.

Most importantly:

ALWAYS READ AND FOLLOW PESTICIDE PRODUCT LABELING. It is a violation of Federal and state law to use any pesticide product in a manner inconsistent with its labeling.

The U.S. EPA will allow its approval of dicamba tolerant soybeans to run until the end of 2018. At that point they will consider whether or not to renew approval based on the amount of problems that arise as a result of this new technology. In order to have this technology in the future, proper stewardship by the grower is essential. If you have questions regarding the use of dicamba tolerant soybean technology or dicamba itself please contact Matt Morris @ 301-600-3578 / mjmorris@umd.edu or contact your local Extension office for more information.

 References and other Resources:

-University of Illinois Extension. The Bulletin. Dicamba and Soybean: What to Expect in 2017. http://bulletin.ipm.illinois.edu/?p=3765

-Purdue University Extension ID-453-W. 2,4-D- and Dicamba Tolerant Crops- Some Facts to Consider. https://www.extension.purdue.edu/extmedia/id/id-453-w.pdf

-Reviewed by Ron Ritter, Professor Emeritus, University of Maryland

JUST-IN-TIME PESTICIDE INFO – Water Soluble Packaging Label Changes

Dr. Amy E. Brown, Professor, Department of Entomology, University of Maryland

The Agricultural Handler Exposure Task Force (a group formed by multiple registrants of agricultural products to generate exposure data in support of registration) uncovered a problem with water soluble packaging while conducting exposure studies for water soluble packaging. They observed improper use of products in water soluble packaging, such as spraying the products with high pressure water and intentional breaking of water soluble bags. The task force notified EPA of their observations and  offered draft label language to address the improper use of the products. A draft set of instructions is included in the attached pdf. (Water Soluble Packaging Label Change)

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