2015 small grains disease outlook

March 28, 2015 in Barley, Barley diseases, Wheat, Wheat Diseases

For the second year in a row, we are dealing with the aftermath of a cold, prolonged winter.  In addition, a wet end to the summer resulted in much of the small grains being planted later than normal.  How might this impact the 2015 diseases and what should you be looking for?

Barley yellow dwarf virus (BYDV) is unlikely to show up in any significant amount.  This virus is spread by several species of aphid, and severity and intensity is related to the amount of aphid activity early in the season.  Late plantings coupled with a cold, prolonged winter make it highly unlikely to see much of this disease in 2015.  BYDV symptoms will be most evident around heading, and manifest as discolored flag leaves, stunted plants, and deformed heads.

Other cool season viral diseases that prefer wet soils, such as Wheat Spindle Streak Virus may be more pronounced in fields where this virus has appeared in the past.  Look for stunted, plants before Feekes 8.  Stunted plants often occur in low lying areas of the field , but may also be found throughout the field in some instances.  Viruses can only be confirmed through special tests such as PCR or ELISA.

A cool , delayed spring means that our crop is a behind.  The cool temperatures in the south have resulted in flare ups of Stripe rust.  Stripe rust needs to blow up to our region from southern areas, and the combination of a high inoculum load in the south, cool temperatures, and a delayed crop increase the chance that we might see a bit of this disease in 2015.  Keep an eye out for this disease as under the right conditions flare ups can cause some significant reductions in yield.  Click here for a detailed factsheet from KSU on stripe rust.

 

 

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Glyphosate application does not increase Soybean Sudden Death Syndrome

March 9, 2015 in Soybean, Soybean Disease Management, Soybean diseases

Sudden death syndrome (SDS) is a soilborne disease of soybeans caused by the fungus Fusarium virguliforme.  This disease infects soybeans during the seedling stage during prolonged periods of cool, moist weather, resulting in root rot.  Rains at the reproductive stage of growth cause the fungus to deeply colonize the roots and produce a toxin, resulting in the characteristic interveinal necrosis.

A leaf with interveinal chlorosis characteristic of SDS

A leaf with interveinal chlorosis characteristic of SDS Photo by N. Kleczewski

If you are lucky, you will see blue growth around the soil line, which is indicative of SDS.

Blue growth (within circle) on the roots or soil line indicates the presence of SDS.  Photo by N. Kleczewski

Blue growth (within circle) on the roots or soil line indicates the presence of SDS. Photo by N. Kleczewski

 

SDS has become a yield-limiting disease in high input fields in the Midwest, and is present at low levels in the mid-Atlantic.  Glyphosate-resistant soybeans are commonly planted because they facilitate weed management.   Over 90% of soybeans planted in the United States contain glyphosate resistance.  There have been reports of glyphosate related issues with diseases in soybeans, including SDS, with some studies showing an increase in disease, and others indicating a reduction of disease when glyphosate is used.

A paper recently published in Plant Disease  examined the effects of glyphosate on SDS severity, grain yield, and plant nutrition in studies conducted across five states in the US  and one site in Ontario, Canada from 2011-2013.  What did they find?  There were no effects of herbicide on disease, and treatments with glyphosate tended to yield more than treatments with non-glyphosate containing herbicides.  In addition, there were no effects of glyphosate on plant nutrition.   For additional information follow THIS LINK

Reference: Kandel, Y. R., Bradley, C. A., Wise, K. A., Chilvers, M. I., Tenuta, A. U., Davis, V. M., Esker, P. D., Smith, D. L., Licht, M.A., and Mueller, D. S. 2015. Effect of glyphosate application on sudden death syndrome of glyphosate-resistantsoybean under field conditions. Plant Dis. 99:347-354.
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UD Nematode Assay Service 2015

March 7, 2015 in Soybean, Soybean Disease Management, Vegetables

The University of Delaware realizes the importance of a local nematode assay service to our growers. However, changes in staff and resources have required us to change when and how this service is offered. To maximize resources, predictive soil nematode assays will only be conducted by the service from April 1- May 1, 2015 and from October 1-November 1, 2015Soybean cyst nematode (SCN) egg assays, the most accurate means of assessing SCN, will be available throughout the season.

Fields with issues during the growing season (troubleshooting samples) will be accepted as needed; however, Dr. Nathan Kleczewski must be contacted prior to submitting troubleshooting samples at nkleczew@udel.edu or 302-300-6962.  Remember that the service only accepts commercial vegetable and field crop samples from within Delaware.

The UD Nematology fee schedule can be found here:  https://commerce.cashnet.com/cashnetc/selfserve/BrowseCatalog.aspx

 

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Fungicides and potency

March 3, 2015 in Barley diseases, Corn Disease Management, Soybean Disease Management, Wheat Diseases

Fungicide selection can be a challenging process, and growers often need to take into account many factors in deciding on a product.  Disease history, variety susceptibility, cost, and performance are important factors that go into the overall equation for selecting a product.  One statement you may hear sounds something like this:

“I’m going with Product X because it has more of triazole1 than Product Y, which has a lower amount of triazole 2 for this price”.

Let’s change that statement around, but this time let’s say the individual is in the demolition business.  “I’m going with black powder over plastique because I get less plastique for this price.”

That statement is true, but the amount of powder needed to do the same job as a given amount of plastique is much greater.  Thus, the comparison doesn’t really make sense.

The same goes for our fungicides.  Potency can vary significantly within a fungicide class.  Thus you may only need to go out at a 6 oz rate for one product to achieve the same level of disease suppression that you may achieve at a 10 oz rate for another product.  In addition, the inactive ingredients play vital roles in the performance of fungicides.  Premixes are another issue, as sometimes synergism occurs-the activity of the actives in a mixture are greater than what would be expected if they were applied solo.  Keep this in mind going into the field season.

 

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Nematode Management and Nimitz Training Offered

February 25, 2015 in Vegetables

Location: University of Delaware, Carvel Research and Education Center,
16483 County Seat Highway, Georgetown, DE 19947
Time: 8:30 a.m. – 12 p.m.

Date: April 20th, 2015

Registration: Please call Karen Adams at (302) 856-2585 ext. 540 to register

Vydate will be in short supply for at least 2015, and growers have few options for root knot nematode management in vegetables. This technical session will cover fumigant options for nematode management and training in the use of Nimitz, a new contact nematicide offered by Adama®. Speakers will include Dr. David Langston from Virginia Tech, and Pablo Navia Gine, Innovation Technical Leader at Adama®. Participation will be limited to the first 90 registrants.  Food will be provided.

Nathan Kleczewski – Extension Plant Pathologist UD and

Kate Everts – Extension Vegetable Pathologist UD and UMD

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Vydate to be limited in supply in 2015

February 11, 2015 in Vegetables

You may have heard that the Vydate plant in Texas has closed temporarily.  Consequently, expect this product to be limited during the growing season.  This is unfortunate news as Vydate is a fairly economical means to suppress root knot nematodes in many vegetable crops.

Unfortunately we do not have many alternatives.  Liquid fumigants such as Telone II can work, but often are not economical.  I mentioned a new product from Adama called Nimitz.  This is a synthetic, contact nematcide that acts on the nematode cuticle.  The data I have seen shows that it performs fairly well, but there are some issues with stunting and phytotoxicity.  According to Adama the product can be applied preplant either as a broadcast or banded application.  The product is then worked into the ground and allowed to set for 14 days.  During this period, two typical irrigation cycles should be run to 1) allow the product to move deeper into the soil profile and 2) dilute the product.  A final concentration of 1ppm is what you are shooting for with this method.  Another key is to apply the product when temperatures are above 65 degrees F.  This ensures that the nematode population is active and more likely to encounter the product in the soil.  I have also heard from some colleagues in the South that stunting and phytoxicity may increase in cooler conditions.  Adama does offer training sessions on Nimitz to consultants and growers to familiarize them with proper use of the product.

Unfortunately not many people have experience with Nimitz, particularly in this area.  Hopefully we can get a look at it and some other pipeline products in the upcoming season.  In the meantime, realize that there may be a shortage in Vydate this year and adjust your programs accordingly.

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Nimitz nematicide recieves approval from EPA

January 29, 2015 in Vegetables

The following is a press release pertaining to Nimitz, a new nematicide that recently was granted approval by the EPA.  I believe that this product will be a great tool in our vegetable crops in the future.

Raleigh, North Carolina (January 5, 2015)–ADAMA, a world leader in customer-focused agricultural solutions, announced today that NIMITZ, a novel, non-fumigant nematicide with simplified application features and unmatched user safety, has received federal registration from the EPA.

The active ingredient in NIMITZ has a unique mode of action which categorizes the product within a new chemical classification. The U.S. is the first country to receive a federal registration, with approved crop uses on cucurbits, (including cucumbers, watermelons, cantaloupe and squash), and fruiting vegetables (tomatoes, peppers, okra and eggplants).

“NIMITZ is the nematicide that growers have been waiting for,” says Herb Young, ADAMA brand leader. “It is highly effective in controlling plant-parasitic nematodes. It also has a ‘Caution’ signal word which has never existed until now for a chemical nematicide. No other nematicide in the world currently has this same mode of action or classification.”

ADAMA’s latest entry is a new paradigm for nematode control on high value crops. NIMITZ eliminates stringent use requirements of fumigant nematicides including Fumigant Management Plans, re-entry intervals (REI), 24-hour field monitoring and restrictive buffer zones.

“In contrast to fumigant nematicides, NIMITZ simplifies nematode management by lessening complex handling practices and application restrictions,” says Young. “NIMITZ has no REI and does not require certified applicator training. Also, personal protective equipment (PPE) is minimal.”

Revolutionizing global nematode control

Nematodes are among the most destructive and problematic pests for growers worldwide, causing yield loss of more than $100 billion annually. In the U.S., restricted use pesticides, primarily fumigants, have been a traditional means for controlling nematodes.

Since 2007, more than 1,000 field trials and hundreds of regulatory studies have been conducted in 23 countries to demonstrate the effectiveness and unique handling benefits of NIMITZ. This research consistently shows nematode control with NIMITZ as being competitive with the most popular commercial standards.

“As the first new chemical nematicide to be developed in more than 20 years, NIMITZ will fill an industry-wide demand for highly-effective nematode control as companies phase out older, more toxic and environmentally-hazardous nematicides,” says Pablo A. Navia, ADAMA innovation technical leader. “NIMITZ provides a non-restricted use pesticide alternative that is effective, easy to apply, and with lower environmental impact.”

Cited by Navia as a ‘true’ nematicide, NIMITZ causes irreversible and rapid nematicidal activity immediately following an application. Within one hour of contact, nematodes cease feeding and quickly become paralyzed. Within 24 to 48 hours, pest mortality occurs rather than temporary nematostatic (immobilizing) activity, as seen with organophosphate and carbamate nematicides.

Product application, future registrations

Since NIMITZ is a contact nematicide, not a fumigant, it frees growers from many of the complications, equipment requirements, liabilities, and dangers associated with fumigant nematicides without compromising control.

NIMITZ application options include drip-injection, and broadcast or banding with mechanical incorporation.

ADAMA reports that the process for MRLs has been initiated for the export of produce. The company expects to obtain further registrations of NIMITZ in more countries and crops.

According to Young, NIMITZ’s unique and safer features exemplify ADAMA’s commitment to bringing simplicity to agriculture. He explains, “EPA summarized this new active best in the Federal Docket [EPA-HQ-OPP-2012-0629, July 25, 2014], ‘Fluensulfone (NIMITZ) represents a safer alternative for nematode control with a new mode of action and a much simpler and straight forward product label.’”

For more information about NIMITZ, contact ADAMA at 866-406-6262.

 

Contact:
Christa Miller
919-256-9317
Christa.miller@us.adama.com

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2014 applied field crops research available

January 27, 2015 in Barley, Barley diseases, Corn, Corn Disease Management, Soybean, Soybean Disease Management, Wheat, Wheat Diseases

I have put together a book that summarizes much of our applied plant pathology research from the 2014 field season.  The guide is intended to provide clientele from Delaware and the surrounding region with up to date, research-based information on applied management of current or emerging diseases in the mid-Atlantic.

Access the book by clicking this link:Kleczewski Applied Field Crops Research 2014

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2015 Fungicide Resistance Management Booklet Now Available

January 22, 2015 in Vegetables

Fungicides contain active ingredients with a specific mode of action.  The mode of action typically refers to a particular physiological process essential to the fungus.  For example, fungicides in the group 7 (SDHI) class impact energy production by inhibiting a process at one point  of the energy production pathway, whereas the group 11 (QoI) fungicides impact energy production by inhibiting a different part of this same pathway.  Other fungicides can prevent DNA replication, RNA production and signalling, cell division, cell wall synthesis and integrity, and other processes important for the survival and reproduction of fungi.  When fungicides on the same class are applied repeatedly in a location it can result in a buildup of individuals with a natural resistance or tolerance to the fungicide in the population.  This resistance results in a general lack of fungicide effectiveness for this particular fungicide class in the future.  One way to avoid resistance issues is to rotate among products belonging to different fungicide classes and to understand the resistance risk of a particular fungicide.

 

Each year we put together a fungicide resistance guide with the cooperation of plant pathologists throughout the mid-Atlantic and Northeast.  This guide is an excellent resource for those growing vegetables and utilizing fungicides during the growing season.  A pdf of the guide can be found by clicking the link below:

2015 FRAC Guide

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iLeVO: A New Tool for Soybeans

December 31, 2014 in Soybean, Soybean Disease Management, Soybean diseases

iLeVO, a seed treatment containing Fluopyram recently gained approval for use by the EPA.  Those of you who grow vegetables or orhards are likely already familiar with this active ingredient as it is a major component of the Luna fungicide product line.  Fluopyram is of the newer group 7 fungicides, which inhibit an essential enzyme in the respiratory pathway, preventing energy production.  This results in inhibition of spore germination, germ tube elongation (essential in penetration of plant tissues for many fungi), growth, and sporulation.  Interestingly, Fluopyram also has activity against nematodes.  This molecule was released in recent years in Honduras for use as a nematicide in bananas, and now it is available as a seed treatment in soybeans.  It’s also a component of seed treatments in small grains in Europe, and a few other uses here and there.

From the data I have seen, the best use of this product as a seed treatment is in areas with high levels of Sudden Death Syndrome (SDS) and Soybean Cyst Nematode (SCN) pressure.  Data indicates that in these situations, under the proper environmental conditions, you may see yield benefits in the range of 3-10 bu/A.  I have also seen some data that indicates that Fluopyram may have activity against root knot nematode as well.  There is still some debate on weather this is a true nematicide or simply a nematistatic product.  There is some research that indicates that this may be more of a nematastatic product, meaning that it might slow down the nematodes or “screw them up” for a period of time, allowing the plant to grow larger and better tolerate their future activity.

A couple things to keep in mind: 

1)  data indicates that you may see stunting initially with this product, but yield is not affected.

2) we have not tested these in our soils in DE and MD, so it would be nice to see some on farm trials to see what this might do in terms of benefiting growers in our growing conditions (high sand, irrigation, our tillage systems, our soybean varieties, etc.).

3) some growers have SDS, but not to the extent that they have it in the Midwest.  In Delaware in particular you will see patches here and there, but the impact on yield here is suspect.  We also have many fields that do not have SDS that are claimed to have this disorder.  You really need to have this disease confirmed by your diagnostic clinic or Extension Plant Pathologist to be sure.  I’ve seen fields where SDS was suspected but the issue was compaction, virus, even Frogeye leaf spot.  Remember:  Effective management starts with disease confirmation.

4) you are not likely to see SDS in double-crop soybeans due to increased temperatures which does not favor SDS foliar and root rot symptoms.

5) rotation to a non host crop, such as corn, can reduce SCN by up to 55% in a single season, so if you have been bit by SCN this year in a few fields, consider rotating to corn in impacted fields in 2015 and perhaps go back to soy in 2016.  Managing SCN is through reducing populations, and rotation is the easiest and best way to accomplish this.

 

The news release can be found here: NEWS RELEASE

My factsheet on SDS can be found here: SDS in Soybeans

The views expressed here are for educational purposes and do not constitute an endorsement of the product.

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