Monday June 16th Ag News

Glyphosate-Resistant Common Ragweed Confirmed In Nebraska
Lowell Sandell, Weed Science Extension Educator

Glyphosate dose response studies have confirmed a glyphosate-resistant population of common ragweed (Ambrosia artimisiifolia) from southeast Nebraska. This population survived doses up to eight times the suggested labeled use rate. While this would not be considered a high level of resistance, it is clear that labeled use rates would not provide acceptable control.

This is the first confirmation in Nebraska, however glyphosate-resistant common ragweed populations have been reported in 14 other states dating back to 2004. Thirteen of the 14 listed cases were reported in soybean environments. Nebraska producers with common ragweed in their fields should be able to identify this weed and closely monitor the performance of their herbicide programs where common ragweed is present. 

Where You'll Find It
Glyphosate-resistant common ragweed has been confirmed in Alabama, Arkansas, Indiana, Kansas, Kentucky, Minnesota, Mississippi, Missouri, New Jersey, North Carolina, North Dakota, Ohio, Pennsylvania, and South Dakota.

In Nebraska common ragweed traditionally has not been one of the most problematic species in corn and soybean production fields. However, when present and left uncontrolled it can have a significant impact on soybean stands, growth, and yield.

Common ragweed is a summer annual broadleaf plant and is found in many environments including urban areas, roadsides, ditches, gardens, landscapes, unmanaged areas, and row crops.

Glyphosate, HPPD, and auxin herbicide-resistant weeds have been confirmed over the last six years in Nebraska. This continued confirmation of herbicide-resistant weeds indicates not enough producers have diversified their weed management approach to prevent or delay the evolution of herbicide-resistant weed populations.



Diseases in Damaged Corn
Tamra Jackson, Extension Plant Pathologist
Nathan Mueller, Extension Educator, Dodge County

Recent severe weather presents special challenges to crop production. Specifically, there are numerous corn diseases that can develop in wounded corn, some of which are already beginning in corn affected by frost, flooding, damaging winds, and hail.

Corn that has been wounded during inclement weather can become infected with any of several bacterial pathogens that commonly occur and cause diseases, such as Goss's wilt and blight, bacterial stalk rot, etc.  Early stages of some of these diseases are being reported in corn in a few areas of south central and southeast Nebraska, especially where corn was previously damaged.

Symptoms
Affected corn has one or more of the following symptoms:
-    water-soaked lesions,
-    wilting, discoloration,
-    internal decay, and
-    sometimes unpleasant odor.

Microscopic examination of some plants this week revealed bacterial streaming from plant tissue and other evidence of bacterial infection, and potentially other pathogens.  Systemic infection evidenced in some plants will likely lead to death.

Some of the diseased plants displayed symptoms that are common in plants infected with the bacteria that cause Goss's wilt and blight.  Goss's wilt could be a likely problem in fields with a history of the disease. Systemically infected plants often will be discolored inside the stems. Other symptoms on the leaves may appear somewhat different than the classic leaf blight symptoms usually observed with Goss's wilt, such as the dark freckles near the edges of lesions. Glossy exudate may be visible on the surface of leaves and is common in plants with Goss's wilt, but may occur with some other bacterial diseases, too.

Since the pathogens causing these diseases are somewhat common in fields, plant may have more than one disease.

Stalk rots (including bacterial stalk rot) and lodging are common in areas that were flooded.  Revisit these areas throughout the season to monitor stalk quality and prioritize fields for harvest to avoid losses due to lodging. One reason stalk rots tend to develop in corn that was flooded is  the loss of nitrogen during heavy rain and flooding. (See related CW story.)  Nitrogen-deficient plants often use more resources in the stalks during grain fill, leaving them weakened and prone to disease and lodging.  For more information about stalk rot diseases, see the UNL Extension Circular, Common Stalk Rot Diseases of Corn (EC1898).

Diagnosis and Management
Since several bacterial diseases may appear similar, it is necessary to submit a sample(s) for diagnosis and confirmation.  Unfortunately, there is no treatment recommended for Goss's wilt or other bacterial diseases at this point.

For more information, please see the UNL NebGuide, Goss's Bacterial Wilt and Leaf Blight of Corn (G1675).

Common Smut
Common smut is caused by a fungus that occurs in almost every field.  The fungus can infect anytime during the season, although most people will recognize its mushroom-like galls on ears and tassels that are filled with black/brown soot-like spores.  The fungus can infect plants at any stage, but especially when wounded.

Galls may develop on leaves, but will often appear smaller and more wart-like and may not contain the large amounts of spores. This will be more common in more susceptible field corn, seed corn, and sweet corn.  Although leaves may be disfigured, the infection will not spread in the plant and the plant will often recover from the infection.

There are no treatment options for common smut during the season.  For more information see the UNL NebGuide, Smut Diseases of Corn (G2223).

For help diagnosing a plant, submit a sample to the UNL Plant & Pest Diagnostic Clinic.



NEW UNL Irrigation Pumping Plant Efficiency Calculator App

A new UNL mobile app — IrrigatePump — can help you identify irrigation pumping plants that are underperforming and need to be adjusted, repaired, or replaced with a better design. Developed by University of Nebraska-Lincoln Extension, this app uses existing records to help determine when pumping plants should be tested by a professional.

An easy-to-use design guides the user to input six numbers related to pumping lift, pressure at the discharge, acre-inches of water pumped, fuel price, and total fuel used. The app then calculates a pumping plant performance rating. It also provides an estimated cost to bring the pumping plant up to standard and the number of years necessary to pay back the investment at various interest rates.

This calculator compares the fuel used for your pumping plant with the Nebraska Pumping Plant Performance Criteria (NPC). A pumping plant meeting the criteria is delivering the expected amount of useful work, measured as water horsepower hours (whp-h), for the amount of energy consumed. The NPC is based on field tests of pumping plants, lab tests of engines, and manufacturer data on three-phase electric motors. Survey results in the past have shown many pumping plants used 30-50% more energy than expected by the NPC. Surveys of relatively new pumping plants indicate they're operating at 82%-92% of the NPC. Results are anonymous but can be captured and emailed to yourself.

Developers: Thomas Dorn, UNL Extension Educator Emeritus; Derrel Martin, UNL water and irrigation resources specialist, and William Kranz, extension irrigation specialist
Cost: $1.99
Availability:
-    In the Apple iTunes Store for iPhone and iPad at https://itunes.apple.com/us/app/irrigation-pumping-plant-efficiency/id834448125?mt=8
-    In the Google App Store for Android https://play.google.com/store/apps/details?id=com.movecreative.pumpingplant


NEW UNL Agriculture Irrigation Costs App

A new University of Nebraska-Lincoln mobile app can calculate ownership and operating costs for your irrigation system. IrrigateCost models center pivot and gated pipe irrigation systems and the most commonly used energy sources. The user inputs information such as acres irrigated, pumping lift, system PSI, pump and pivot life, and inches applied as well as related costs such as for the well and engine, labor, energy, district fees, and taxes. The app then calculates total irrigation cost as well as total ownership and total operating costs.  It also breaks down costs by irrigation well, pump, gear head, pump base, diesel engine and tank and system and calculates per acre annual cost and per acre-inch annual cost.

Results for different energy sources are displayed on separate tabs, allowing you to make side-by-side comparisons between energy options.

The calculator is also helpful when computing a fair crop-share rental agreement. Parties often will list all the contributions required for crop production in a table (land, irrigation system, machinery, labor, crop inputs, etc.). By using two columns (one for the landowner and one for the tenant) costs can be determined for each on the inputs. The columns are totaled and a percentage is determined for the landowners and tenants contributions. The "fair" rental arrangement would be to divide the crop on the same percentage as the contributions that each party has made.

The costs of owning and operating the irrigation system are some of the most difficult to identify when analyzing irrigated crop share arrangements. Much of the total cost of irrigation results from ownership costs and a large percentage of ownership costs are not annual out-of-pocket costs but rather hidden costs, such as return on capital investment, depreciation, taxes, and insurance. This app calculates ownership costs for each irrigation system component such as the well, pump, gear head, power unit and the irrigation distribution system.

Additional uses include:
-    Knowing what to charge for watering a portion of a neighbor's field. This app can help you determine the ownership costs the neighbor should pay in addition to the operating costs for each acre-inch of water pumped.
-    Estimating costs to pump an acre-inch of water to help you determine how many additional bushels of a crop are needed by applying one more inch of water at the end of the irrigation season.

Results are anonymous but can be captured and emailed to yourself.

Developer: Thomas Dorn, UNL Extension Educator Emeritus
Cost: $1.99
Availability:
    In the Apple iTunes Store for iPod and iPad at https://itunes.apple.com/us/app/agriculture-irrigation-costs/id700329336?mt=8
    In the Google App Store for Android at https://play.google.com/store/apps/details?id=com.movecreative.irrigatecost



New UNL Youth Crop Scouting Contest Aug. 6

University Of Nebraska–Lincoln Extension will host its first Crop Scouting Competition for Nebraska youth Aug. 6 at the ARDC near Mead. The event will include indoor and outdoor events. Teams of junior high and high school students (those completing 7th-12th grades) from across Nebraska are invited to participate.

The purpose of the competition is:
-    to provide students an opportunity to learn crop scouting and principles of integrated pest management (IPM) for corn and soybeans in Nebraska,
-    to obtain knowledge and skills that will be helpful in future careers, and
-    to demonstrate newer crop scouting technologies.

Schools, clubs or other organizations may enter a team composed of three or four participants. An adult team leader must accompany each team of students. Team leaders could be FFA advisors, crop consultants, extension staff, or co-op employees.

Prizes will be awarded: $500 for first, $300 for second, $250 for third and $100 for fourth place.

Teams will be expected to know the basics of scouting corn and soybean fields, including crop staging; looking for patterns of crop injury; disease, insect and weed seedling identification; etc. Other topics may include pesticide safety, nutrient disorders, and herbicide injury.

More information about the crop scouting competition and instructions on how to register a team are available online at cropwatch.unl.edu/youth. Click on the link "Crop Scouting Competition."

Teams must register by July 15. The registration fee of $50/team must be submitted with the registration by July 15, but will be refunded when the team attends the competition. This program is sponsored by DuPont Pioneer and UNL Extension.



FORAGE FOLLOWING WHEAT
UNL Extension Forage Specialist Bruce Anderson

               Once your wheat is gone, how do you plan to use that ground after harvest?  With lots of growing season left this year there are many forage possibilities.

               Wheat harvest soon will be here.  There will be lots of growing season remaining for producing more forage.

               For example, with good moisture an early maturing corn is one possibility for silage if you plant it thick.  A better dryland choice might be forage sorghum if chinch bugs and other insects are not a problem.  Use high grain producing hybrids when available.  Sunflowers can be a surprisingly good choice for a short-season silage.  They survive light frost and yield well under many conditions.

               If you prefer hay instead of silage, plant sorghum-sudan hybrids, teff, or pearl or foxtail millet when chinch bugs aren't a problem.  A hay crop exceeding two tons per acre still can be grown if planted soon after harvest and rain is timely. Another hay or silage alternative is solid-seeded soybeans.  A couple tons of good forage can be grown from taller, full season varieties planted after wheat.  Oats planted in early August is another option.  Yields over two tons are possible if moisture is good, fertility high, and your hard freeze comes a little late.

               Definitely consider turnips, as well as oats, for fall pasture planted into wheat stubble in late July or early August.  With a few timely rains in August and September, both oats and turnips produce much high quality feed in a short time.  And, they are relatively inexpensive to plant.

               Don't automatically let your wheat ground sit idle the rest of the year, especially if you could use more forage.  When moisture is available, there are many forage options.  One might be right for you.



Kansas State University agricultural economist says El Niño expected to benefit U.S. agriculture

A Kansas State University senior agricultural economist says there's a 70 percent chance an El Niño will arrive this fall — and that's good news for the United States.

Jay O'Neil, an instructor and specialist at the university's International Grains Program, says what happens with El Niño will affect worldwide crop production. El Niño, which is the warming of the sea temperatures off the coast of Peru, is expected to affect crops during September, October and November.

"El Niño is generally favorable to crop production in the United States because it brings extra rain and moisture into the core crop-growing areas," O'Neil said. "We're just coming out of a four-year drought cycle in the United States and we'd like to get back to what we call trend-line yields and big crop production so there's plenty for everybody."

Better crop production in the U.S. would also mean lower food prices. However, other countries would experience harsher growing conditions because of El Niño. O'Neil says South America is expected to be dryer than usual, which would have an impact on the global food market.

"If South America goes dry, that would affect next year's production worldwide," O'Neil said.



Harrisvaccines Becomes First In The Nation To Receive USDA Conditional License For PEDv Vaccine

Ames, Iowa-based vaccine producer, Harrisvaccines, today announced it has been granted United States Department of Agriculture (USDA) conditional licensure of the company's Porcine Epidemic Diarrhea Virus (PEDv) Vaccine, RNA utilizing its SirraVaxSM RNA Particle Technology. This is the first USDA conditional license granted for a PEDv vaccine since the initial outbreak, and it will allow Harrisvaccines to sell their vaccine directly to the veterinarians and swine producers battling PEDv.
Harrisvaccines

PEDv is a highly contagious swine disease that entered the United States in April 2013.  PEDv causes vomiting and diarrhea in older animals and extreme dehydration and mortality of up to 100 percent in piglets that are less than one week of age.  Since entering the U.S. just one year ago, PEDv has spread to nearly 30 states and throughout North America, causing the death of millions of piglets.  PEDv is not a zoonotic disease, and therefore cannot spread to humans, but it has cost the pork industry and consumers hundreds of millions of dollars.

"Using our unique rapid-response production methods, we were able to create a vaccine in a matter of weeks after the outbreak," says Joel Harris, Head of Sales and Marketing for Harrisvaccines.  "Since late 2013, we have sold nearly 2 million doses of this vaccine through veterinary prescription and we are now thrilled to say it has been granted a USDA conditional license."  

"The impact of this disease has been devastating," said Dr. Hank Harris, Founder and CEO of Harrisvaccines.  "At Harrisvaccines, we recognized the great threat that PEDv posed to the industry immediately and that is why we are able to introduce the first USDA conditionally licensed PEDv vaccine on the market."

The USDA generally grants conditional licenses in order to meet an emergency or unmet need. A conditionally licensed product must show a reasonable expectation of efficacy and all safety and purity requirements must be met.  Harrisvaccines has received USDA licensure in the past using SirraVaxSM technology for its Swine Influenza vaccine (September 2012) and an Autogenous Vaccine, RNA for Rotavirus C (January 2013).