Month: July 2020

Cucurbit Downy Mildew is Spreading in Ohio Despite Hot Weather

Micrograph of a tape mount of spores and sporangiophores of the cucurbit downy mildew pathogen from cucumber leaves. Photo by Francesca Rotondo.

Downy mildew continues to spread in Ohio cucumbers despite the hot and mostly dry weather.  Frank Becker, OSU Extension Wayne County IPM Program Coordinator, brought cucumber leaves with downy mildew symptoms to to our Vegetable Pathology Lab on July 23 for confirmation.

We do this by placing a piece of scotch tape on the underside of a leaf lesion then transferring to tape to a glass slide and looking for characteristic spores and sporangiophores (branched, threadlike structures that produce the spores) under a microscope. The samples came from commercial cucumber fields in Wooster and Apple Creek in Wayne County, and both were positive for downy mildew.

Although we have confirmed reports in only Medina and Wayne counties, cucurbit downy mildew is likely present in most northern Ohio counties.  The map of downy mildew reports shows confirmed cases in Ontario, Michigan and western New York as well. All of these reports are from cucumbers; this clade, or strain of the pathogen affects cucumbers and cantaloupe, but not squash or pumpkins. We don’t expect downy mildew on squash and pumpkins until the other known clade, which has a broader host range, migrates to the Midwest from the Southeast.

Cucurbit downy mildew as of July 24, 2020. cdm.ipmpipe.org.

 

 

 

 

 

 

 

 

Fungicide recommendations are posted here.  If you suspect downy mildew in any cucurbit, please send us a sample.  This will help us track the disease and provide early warnings to growers to enable timely protection of cucurbit crops. Our diagnostic service is free to commercial growers in Ohio; gardeners may also send cucurbit downy mildew samples to us free of charge.  Instructions for sample submission are posted here.

Downy mildew in cucumber.

 

 

Do Not Plant These Seeds!!!

The Ohio Department of Agriculture (ODA) has been notified that several Ohio residents have received unsolicited packages containing seeds that appear to have originated from China. The types of seeds in the packages are currently unknown. The packages were sent by mail and may have Chinese writing on them. Unsolicited packages of seeds have been received by people in several other states across the United States over the last several days.

If you receive a package of this type, please DO NOT plant these seeds. If they are in sealed packaging, don’t open the sealed package. Please retain the seeds and the original package labeling for trade compliance officers as they work through this issue. Unsolicited seeds could be invasive species, contain noxious weeds, could introduce diseases to local plants, or could be harmful to livestock. Invasive species and noxious weeds can displace native plants and increase costs of food production. ODA and APHIS work hard to prevent the introduction of invasive species and protect Ohio agriculture. All foreign seeds shipped to the United States should have a phytosanitary certificate which guarantees the seeds meet important requirements.

Leafhoppers, Grasshoppers, and Beetles, Oh My!

Source: Kelley Tilmon, Andy Michel, OSU

As the summer progresses we are receiving reports of insect problems often encouraged by hot, dry weather.  Last week we reported on spider mites and especially if you are in an area of continued dry weather we recommend scouting your soybeans and corn  https://agcrops.osu.edu/newsletter/corn-newsletter/2020-22/watch-spider-mites-dry-areas .

Some areas are also reporting increases in young grasshoppers in soybeans, another insect favored by dry weather.  Grasshoppers of often start on field edges so early scouting may allow for an edge treatment.  Japanese beetles are another common defoliator of soybean that are starting to appear.  Both of these pests fall into a general defoliation measurement, and we recommend treatment if defoliation is approaching 20% on the majority of plants in post-flowering beans.  Download our guide to estimating defoliation in soybean at https://aginsects.osu.edu/sites/aginsects/files/imce/Leaf%20Defoliators%20PDF_0.pdf

A weird problem being reported not just in Ohio but in parts of the Midwest as far-flung as Minnesota is the red headed flea beetle, which is being found in corn and soybean.  This is a small, narrow, shiny black beetle with a red head which springs like a flea when disturbed.  Feeding in soybean creates small round holes and in corn longer narrow strips of damage.  This feeding is seldom economic.  In soybean follow the general defoliation threshold of 20%.  Leaf feeding in corn is almost never economic, but be on the watch for silk-clipping, which is rare but possible.  There are no thresholds in corn, but our Minnesota colleague Bruce Potter suggest this guideline: “flea beetles are very numerous (it is likely more than 5-10/plant), pollination is less than 50% complete, and numerous plants have silks clipped to within 1/2 inch, you might consider an insecticide.”

Finally, earlier in the season we reported higher than usual numbers of potato leafhopper in alfalfa and encouraged stepping up scouting.  In some fields third-cut alfalfa is being heavily impacted by this insect.  You can review our scouting advice for this insect at https://agcrops.osu.edu/newsletter/corn-newsletter/2020-17/time-start-scouting-potato-leafhoppers-alfalfa

Pasture- Finished Beef Production Online Workshops

Three concurrent sessions, 7:00 pm – 9:00 pm Eastern Time each day:

August 11:

Pasture-finished Beef Production Overview              Greg Halich, University of Kentucky

Forages and Grazing Management                             John Fike, Virginia Tech

 

August 12:

Cattle Selection and Winter Management                  Ed Rayburn, West Virginia University

Marketing and Processing                                           Kenny Burdine and Greg Halich, Univ. KY

 

August 13:

Producer Panel

Putting it All Together – Systems Approach             Greg Halich and Ed Rayburn

 No Cost but need to REGISTER at: https://vaforages.org/pasture-finish-beef/

 

Pasture Management in Dry Weather

Dr. David Barker, Professor – Horticulture and Crop Science, The Ohio State University

Dry weather in recent weeks throughout Ohio has raised several questions about how pastures should be managed during drought. Although the experts don’t all agree if this period of dry weather meets the definition of a drought (yet), there is no doubt that pasture growth will slow to zero. How should we be grazing our pastures in mid-summer?

Avoid over-grazing
Unfortunately, without rain or irrigation pastures will not grow, and close grazing will exaggerate this effect. Leaf removal by grazing (or mowing) results in a roughly similar proportion of root death. During moist conditions, roots can recover quite quickly, however, grazing during drought will reduce water uptake due to root loss. As a general rule of thumb, grazing below 2 or 3 inches will accelerate drought effects on pastures, and also, slow recovery once rain does come. Of course, optimum grazing height and management varies with pasture species. As summer progresses into fall we will increase pasture grazing heights and leave more residual, while increasing resting periods. More leaf means less water runoff.

Continue reading Pasture Management in Dry Weather →

Utilizing Cover Crops as Livestock Forage

Utilizing cover crops as forage not only provides feedstuffs for meeting the nutritional needs of livestock, but also offers soil health benefits. In this presentation originally offered during the COVID-19 quarantine period in April, 2020, OSU Extension Educator Christine Gelley discusses cover crop forage selection, seeding, management and harvest opportunities.

Beating the Heat – Tips for Dealing with Heat Stress

– Dr. Katie VanValin, Assistant Extension Professor, University of Kentucky

Heat stress is a problem that can affect cattle throughout the United States. However, in Kentucky and across the southeast cattle are at risk for experiencing more frequent and severe heat stress events than in other regions of the country. Heat stress occurs when cattle cannot dissipate or get rid of excess heat, and there are a multitude of factors that can impact how susceptible an individual animal is to heat stress. These factors include things such as breed, stage of production, age, and hair coat color which can make it difficult to predict an animal’s susceptibility to heat stress. Heat stress results in decreased growth and reproductive performance and in severe cases even death; thus, it is not a problem that should be overlooked.

Continue reading Beating the Heat – Tips for Dealing with Heat Stress →

Ready to manage spider mites?

With the current hot and dry weather conditions in Ohio, we expect to hear reports of spider mite outbreaks on specialty crops. Because mites are tiny, they are often overlooked or misdiagnosed as a disease. Infested leaves have fine webbing on the leaf undersides. Tomato leaves damaged by spider mites usually have yellow blotches, while bean leaves show white stipples or pin-prick markings from mite feeding. Pumpkins can tolerate moderate levels of mites, but watermelons are more sensitive to injury from mite feeding. A simple method of diagnosing spider mites is to shake leaves over a piece of paper and look for moving specks that are visible to the naked eye. A closer look with a magnifier can show the tiny mites that are white, marked with two large dark spots on the middle of the body.

Continue reading Ready to manage spider mites? →

TDA Alerts Livestock Producers to Possible Scam

See message below from the Tennessee Department of Ag.  Some Knox County Cattlemen have received these phone calls as well!

NASHVILLE — The Tennessee Department of Agriculture (TDA) is warning livestock producers about a potential scam.

Several Tennessee cattle farmers have recently been contacted by a person or persons indicating they want to buy cattle. The supposed buyer reaches out via text, claiming that a cashier’s check will be sent as payment with money added for shipping, and that the seller should contact the buyer once the payment is received. If the seller indicates they won’t accept a cashier’s check, the conversation ends.

While a cashier’s check is a standard method of payment and typically safe to deposit, sellers should first contact the financial institution where the check is drawn to ensure its validity. There may be insufficient funds associated with the transaction, or the check itself may be counterfeit. To TDA’s knowledge, no Tennessee producers have fallen victim.

“Although at this time it appears that no crime has been committed, we want farmers to be cautious,” Agricultural Crime Unit Captain Greg Whitehead said. “This person appears to be targeting seedstock producers who advertised through reputable agriculture publications. Farmers have avoided being caught up in a possible scam because they’ve alerted each other, their local Extension office, and TDA.”

Good practices to prevent being scammed include researching the potential buyer online before agreeing to a transaction and resisting pressure to act immediately on a sale or purchase. Consumers should be wary of offers to pay over the purchase price, even if there seems to be a valid reason. This tactic is common in check cashing scams.

If you suspect a crime has been committed, please contact the Agricultural Crime Unit at 844-AG-CRIME (844-242-7463) or agriculture.crime@tn.gov.