Tag Archives: Urgent News

IMPORTANT—New Name and Transitioning to an Updated Delivery System

After 12+ years, the Virginia Ag Pest Advisory has been ‘modernized’. As of this week, it will be transitioned to a new format, powered by WordPress and MailChimp software. We are also adding new authors to cover crop updates so are changing our name to the Virginia Ag Pest and Crop Advisory.

As with the old system, you will still receive weekly emails containing important advisories on your mobile or desktop device, and as before, you can scroll the titles and select only those that are important to you. Normal advisories will be delivered each Friday at 1 am and available for reading first thing on Friday mornings. And as before, there is an ‘Urgent’ option that will be used to provide any advisories that need immediate attention.

In addition, all advisories will be posted to the new Blog site: http://blogs.ext.vt.edu/ag-pest-advisory. You may want to ‘bookmark’ this url. If you are not currently on the old Virginia Ag Pest Advisory email recipient list and want to be added, the Blog site provides an easy way for you to do that.

We hope you will be pleased with our new advisory system.

Ames Herbert

Late blight found on Tomato in Leesburg, VA

Unfortunately, late blight has been confirmed in Leesburg, VA by the Plant Disease Clinic in Blacksburg. Potato and tomato growers (especially in the northern part of the Commonwealth) should take precautionary actions and increase scouting. For more information on late blight please refer to the extension publication link about this potentially devastating disease. Please let us know if you have any more questions.

Southern Rust on Corn in North Carolina – Update

Southern rust was confirmed on a sample from Camden County, NC on July 21. At this time, southern rust has NOT been reported in Virginia. Yield of corn at or near the dent stage is unlikely to be impacted by the disease, but less mature corn may need to be protected with a fungicide application. Contact your local extension office for recommendations if you suspect southern rust is in your area. Samples of corn plants with symptoms of southern rust should be submitted to your local extension office or the disease clinic at the Virginia Tech Tidewater AREC (contact Dr. Hillary Mehl, hlmehl@vt.edu). Typically the disease has little impact on Virginia corn since it arrives too late in the season to affect yield, but if southern rust is confirmed in Virginia prior to corn reaching the dent stage (R5), fungicide applications may be warranted. Updates will be provided as more information is obtained.

Southern Rust on Corn in North Carolina

Southern rust, a potentially devastating disease of corn, has been reported from several counties in North Carolina. At this time, southern rust has NOT been reported in Virginia. Samples of corn plants suspected to be infected with southern rust should be submitted to your local extension office or the disease clinic at the Virginia Tech Tidewater AREC (contact Dr. Hillary Mehl, hlmehl@vt.edu). Signs of the disease are pustules filled with powdery masses of orange spores (see attached photo). Typically the disease has little impact on Virginia corn since it arrives too late in the season to affect yield, but if southern rust is confirmed in Virginia prior to corn reaching the dent stage (R5), fungicide applications may be warranted. Updates will be provided as more information is obtained. Additional information: southern-rust-on-corn-jpg

Sclerotinia blight advisory

Sclerotinia blight has been confirmed in a peanut field in Surry County, VA. According to the Sclerotinia advisory, the current risk for Sclerotinia in Virginia is HIGH and scouting for the disease is recommended. Cool temperatures and high humidity favor disease development. Signs and symptoms of Sclerotinia blight include rapid wilting and death of infected branches, bleaching of stems, and white, fluffy fungal growth on stems, leaves, or pegs. Once Sclerotinia is identified in a field, a fungicide spray such as Omega is the best way to limit further development of the disease. For more information see the Peanut-Cotton Infonet (http://webipm.ento.vt.edu/cgi-bin/infonet1.cgi) or contact Dr. Hillary Mehl, Extension Plant Pathologist at the Tidewater AREC (hlmehl@vt.edu).

Reports of Lygus bugs in cotton—a false alarm for Virginia

There is a lot of conversation about the big Lygus bug outbreaks in northeast North Carolina cotton, and that the pest is moving north. The first part is true. There are areas in NC that are experiencing Lygus bug pressure, especially in their eastern blacklands and in cotton fields near potato fields. The second part is not true. Lygus bugs do not migrate from south to north but are a localized pest that moves from host plant to host plant based on factors like—when the alternate host plants dry down (like weeds) or are harvested (like potatoes).
First, let’s be sure we know what bug we are talking about. Lygus lineolaris, or tarnished plant bug (a. k. a. —Lygus bug or plant bug) is a very common insect in our area. Small numbers of adults and nymphs can be found on almost any weed or crop that flowers. It is a small insect, about ¼ the size of an adult green or brown stink bug, that feeds in a similar manner to stink bugs by inserting its small beak into squares and bolls to extract plant fluids. Feeding can kill small squares and cause stink bug-like injury symptoms to small bolls. Lygus bugs can be a sever pest of cotton in some areas of the US like the Delta and Mid-south cotton states where growers battle this pest with 4 to 8 or more sprays each year. Infestation levels in the eastern states have always been much, much lower. Jack Bacheler, before he retired from NC State, used to quote total percentage cotton acreage treated annually for Lygus bugs to be on average only about 1 – 2 percent. In Virginia, I have only encountered or heard about a very few fields that were infested at levels that warranted treatment. The most recent was last summer on our Eastern Shore where a cotton field next to a potato field was damaged extensively when the Lygus bugs migrated out of the potatoes after they were dug. This is a ‘classic’ case, and one that occurs a lot in the potato production area of northeast North Carolina.
So, this ‘mysterious’ Lygus bug pest is not—mysterious, that is. We understand it, and we have good methods for determining if it is a real threat to a field. To scout for Lygus bugs you need to 1) check for missing squares (percent square retention), and 2) check for presence of adults or nymphs. Neither alone will give you the whole picture. You need to do both—check for missing squares, and check to see if bugs are active. Checking for only missing squares can mislead you because other stresses in the environment can cause small squares to shed (e.g., extreme heat, drought, periods of cloudy weather). Documenting the presence of Lygus bugs does not give the whole picture either because adults are extremely mobile and can rapidly move in and out of fields. Sometimes they may be present, but not causing square injury or loss.
Weekly checks of upper square retention is the most efficient way to assess if Lygus bugs can either be ruled out as an economic concern at that time or if sweep netting for the adults and nymphs is needed. An upper square retention rate of 80% or more usually indicates that Lygus bugs are not present at damaging levels. In most years in Virginia, percent square retention is very high – often in the mid to upper 90’s. A recent (July 1 and 2, 2014) check of 8 randomly selected fields showed they had greater than 95% square retention. If upper square retention is less than 80%, you should use a sweep net to sample in eight to 10 locations in the field away from the edge, looking for live adult and immature Lygus bugs. If a field has less than 80% square retention and an average of eight Lygus bugs per 100 sweeps, a spray is needed at that time. Remember that when cotton is approximately one week into blooming, a five-foot black beat cloth is a more accurate sampling devise than the sweep net for Lygus bug, especially the nymphs which show up as almost florescent green on the black cloth background.
If a threshold is met and a treatment is needed, here is an example of a spray plan shared by NC State. For the first Lygus bug spray pre-bloom, at squaring or first flower, consider using a stand-alone neonicotinoid product (common examples include Admire Pro, Belay, Centric, Intruder, Trimax Pro). These are generally softer on beneficial insects so conserve them. If Lygus bugs are still a concern later on, or require a second spray, first check to see that aphids are not common in the field. We have been lucky in VA with having very little aphid pressure in cotton in the last few years, but if aphids are present, you should not use a neonicotinoid again. Switch to a product like Carbine, Transform, or one of the more effective pyrethroids. If aphids are not a concern, you should still not use a stand-alone neonicotinoid product for a second spray, but should switch to one of the pre-mixed products (like Endigo, Leverage, Swagger, etc.) that also contain a pyrethroid, or an organophosphate/carbamate-only product (like Bidrin, Orthene, Vydate, etc.). Many of these products are also effective against stink bugs; eliminating stink bugs can be beneficial during the period of boll formation. The downside to these products is that they kill beneficial insects and put the field at higher risk for bollworm and spider mites—so if any of these products is used, be sure to scout these fields later in the season.

Head scab advisory

If your wheat is flowering, it may be at risk for head scab (Fusarium head blight, FHB). FHB is caused primarily by the fungus Fusarium graminearum. Infection of wheat heads with this fungus can result in significant yield loss and contamination of the grain with deoxynivalenol (DON or vomitoxin). Risk of FHB can be determined using the Fusarium Risk Assessment Tool (http://www.wheatscab.psu.edu/). As of today (May 5) many areas in eastern and central Virginia have a moderate FHB risk; portions of the Eastern Shore (Accomack County) have a high risk. Early flowering is the best timing for fungicide applications. Prosaro, Proline, and Caramba are the most effective products to reduce FHB and DON. If a strobilurin is applied at or after heading, and IF scab infections occur, DON levels are likely to be elevated compared to a triazole or even an unsprayed check. Information on FHB can be found in the Virginia Tech Extension publication “Managing Fusarium Head Blight in Virginia Small Grains” (http://pubs.ext.vt.edu/3102/3102-1535/3102-1535.html). Additional information: fhb-virginia-tech-pdf

25th Annual Eastern Shore Ag Conference and Trade Show

Please find attached the program for the 25th Annual Eastern Shore Ag Conference & Trade Show on January 7 and 8, 2014. The event will be held at the Eastern Shore Community College Workforce Development Center, 29300 Lankford Highway, Melfa, VA 23410. This event is free and open to the public with no registration required. Feel free to pass on to any email lists, stakeholders, etc. that may be interested. Continuing education credits for Certified Crop Advisers will be offered. Any further program changes, weather advisories, and so forth will be posted on my Facebook page: https://www.facebook.com/EasternShore.Soils
Thank you,
Additional information: agconfprogram2014-3january2014-pdf

Workshop entitled “Getting Started in Vegetable Production” – January 27, 2014 Hershey, PA

On Monday January 27, 2014 a workshop “Getting Started in Vegetable Production” will be held prior to the Mid-Atlantic Fruit and Vegetable Convention at the Hershey Lodge, Hershey, Pa. The convention runs from January 28-30, 2014. This workshop is intended for beginning vegetable growers or those thinking about getting into the production of vegetables. The workshop will cover important topics that growers need to think about when contemplating entering into growing vegetables. The speakers at the workshop have years of experience working with vegetable growers and will provide a wealth of information that will prove useful to beginning and new growers. The cost of the workshop is $35.00 and will be separate from the registration for the convention. For more information on registration contact Bill Troxell, Executive Secretary, Pennsylvania Vegetable Growers Association at “William Troxell” or phone: 717-694-3596.