Where It’s Dry, Pest Concerns Are High

Not everyone’s dealing with wet fields. In areas where dry conditions have plagued soybean crops, some pests have been having a field day even this late in the season, and Extension specialists say there are steps retailers and their growers should take.

The key pests at this stag in such areas as Ohio and Kentucky are two-spotted spider mites, bean leaf beetles, and soybean cyst nematodes.

  • Two-spotted spider mitesbecome active when fields are dry, and in Ohio, Ohio State University Extension entomologists have reported some outbreaks, especially along field edges. The two-spotted spider mite feeds on the sap of the soybean plant causing injury. Large spider mite populations, running in the tens of thousands per plant, are enough to kill the crop, causing significant yield losses.

     

    “We continue to think that they will not become whole field infestations, although growers should nevertheless check areas within their fields,” says Ron Hammond, an OSU Extension entomologist. “This is especially important on late-maturing soybeans that were planted late and are still green. Those fields that are starting to yellow are probably past the stage where spraying for mites would be recommended.”

    Yellow/bronze discoloration of plants along field edges or within in a field is characteristic of spider mite feeding. “If growers are finding large populations of adults and eggs on the underside of the leaflets, then treatment is probably warranted,” he says. “If mites have built up sufficiently along the field borders, growers should make an edge spray. This should give late-planted soybeans enough time to continue to make good yields.”

 

  • Soybeans grown for seed, especially late-planted or late-maturing beans, should be monitored for bean leaf beetledamage as leaves begin to yellow and pods remain green, say Purdue University entomologists.

    Bean leaf beetles scar the surface of pods, but only occasionally feed through the pod to the developing beans, explains John Obermeyer, Purdue Extension integrated pest management supervisor, and Larry Bledsoe, Purdue Extension pest management expert. During pod maturation, this scar often cracks leaving an entry hole for airborne plant pathogens that may cause discolored, moldy, shriveled, or diseased beans that show no outward signs of the pathogen.

    Bledsoe says it’s important for pest managers to be able to predict whether economic damage will occur based on the types and numbers of beetles that are present and the stage of pod development (i.e., green, yellow, yellow-brown, or brown pods). Once the pods turn yellow to yellow-brown, they become less attractive and less susceptible to damage. Control is normally not warranted from this point on.

    Obermeyer and Bledsoe recommend randomly selecting two plants from five different areas of the field and then counting the number of pods per plant and the number that show damage. Calculate the percentage of damaged pods per plant for the field as a whole. Note if the pods are green, beginning to turn yellow, or are yellow/brown. Also determine the number of beetles per sweep using an insect sweep net. Take five sets of 20 sweeps in the field. Determine the number of bean leaf beetles per sweep. Additionally, note whether beetles are still actively feeding while surveying the field, they advised.

    There has been considerable interest in bean leaf beetle and its association with bean pod mottle virus (BPMV). Bean leaf beetle is one of major beetle-vectors of this disease. They spread the virus by feeding on infected plants, ingesting the virus with plant tissue, and then regurgitating gut content after moving to and feeding on an uninfected plant. BPMV symptoms at harvest include green stem and hilum bleeding. Treatment for bean leaf beetle to reduce bean pod mottle virus this time of the year is not recommended, as most disease transmission occurs very early in the season.

  • Soybean cyst nematode (SCN)also does damage to soybeans under drought stress. Deemed the “silent robber of yields,” soybean cyst nematodes feed on the roots of young plants, which prevents the roots from taking up vital nutrients. The result is a drop in yields and subsequent economic losses.

     

    Anne Dorrance, a plant pathologist with the Ohio Agricultural Research and Development Center, urges growers to scout their fields for potential SCN populations.

     

    “Where the soybeans are shorter and have fewer pods is a great place to check for SCN on the roots,” said Dorrance, who also holds an OSU Extension appointment. “Dig up the soybeans and shake off the soil, then look for the females. They appear as tiny white pearls, which glisten on the roots.” Notes should be taken and those fields should be sampled in the fall for egg counts through laboratory tests.

     

    “A good accurate egg count in the fall is the first step in soybean cyst nematode management,” said Dorrance. “The best management practice is crop rotation, crop rotation, crop rotation. Once the insect is present, you can’t get rid of it.”

Topics:

Leave a Reply

Insecticides Stories
InsecticidesHow To Scout For Corn Earworms In Corn
July 28, 2014
In her weekly report, University of Missouri Agronomy Specialist Jill Scheidt discusses what to look for when scouting for corn earworm. Read More
InsecticidesEPA Grants Besiege Insecticide Additional Approvals
June 18, 2014
EPA has granted additional registration approvals for the use of Syngenta's Besiege insecticide on sorghum, cereal grains and peanuts. Read More
InsecticidesPrevathon Insect Control Approved For Cereal Crops
January 13, 2014
DuPont's Prevathon insect control powered by Rynaxypyr has received U.S. EPA registration for use on cereal crops, including wheat, most other small grains and sorghum. Read More
InsecticidesInsecticides 2014: Insect Pressure, Solutions On The Rise
January 2, 2014
Bt resistance, weather concerns and myriad other issues have led to an increase in both traditional pest pressures as well as new pests. Read More
Top 100 Articles
CropLife 100Pinnacle Agriculture Acquires Minnesota Retailer
April 14, 2015
Pinnacle Agriculture Holdings, LLC, ranked No. 6 on the CropLife 100,  has successfully acquired Liebl Ag, LLC in Ada, MN.  Read More
CropLife 100CHS, Aurora Cooperative Complete Fertilizer Storage, Grain Shuttle Loading Facility
April 13, 2015
CHS Inc., the nation’s leading cooperative and ranked No. 5 on the CropLife 100, and Aurora Cooperative (ranked No. 21) Read More
CropLife 100GROWMARK Acquires Missouri Refined Fuels Terminal
April 2, 2015
Bloomington, IL-based GROWMARK and Magellan Pipeline Co. have entered into an agreement in which GROWMARK will acquire the refined fuels Read More
CropLife 100Wilbur-Ellis Acquires South Dakota Retailer
April 2, 2015
Wilbur-Ellis Co.’s Agribusiness Division, a recognized leader in precision agriculture technology and the distribution and marketing of plant protection, seed Read More
CropLife 100The McGregor Co. Closes Smith-Kem Acquisition
April 2, 2015
The McGregor Co. — ranked No. 16 on the CropLife 100 list of largest U.S. ag retailers — has completed Read More
CropLife 100BRANDT Commemorates National Ag Day
March 20, 2015
The Illinois agriculture community gathered at BRANDT global headquarters on March 18 to celebrate National Ag Day behind this year's theme Sustaining Future Generations. Read More
Latest News
ManagementSyngenta-Monsanto deal talk; Ohio field work on the mov…
May 6, 2015
Rumors of a deal between Syngenta and Monsanto heat up once again, while planting continues apace in Ohio’s corn and Read More
StewardshipBayer CropScience Announces $100K Pollinator Habitat In…
May 6, 2015
Bayer CropScience is investing over $100,000 in a project with Integrated Vegetation Management Partners, Inc. (IVM Partners) designed to improve Read More
Town & Country Co-op Smithville, OH 4R Nutrient Stewardship Certified
StewardshipThree Town & Country Co-op Facilities Certified In …
May 6, 2015
The 4R Nutrient Stewardship Certification Program has announced that Town & Country Co-op’s facilities located in Loudonville, Smithville, and Sullivan, Read More
Industry NewsMonty’s Plant Food Adds New Territory Manager
May 6, 2015
Monty’s Plant Food Co., a leader in natural soil enhancement and plant  fertility products, has hired Paul Miles as a Read More
InsecticidesVestaron’s Bioinsecticide Now Registered For Use On Mor…
May 6, 2015
Vestaron has received expanded EPA registration for its biological insect control products. These innovative bioinsecticides, which are derived from newly Read More
Sunrise Cooperative Norwalk Agronomy
StewardshipSunrise Cooperative Facilities All Certified In 4R Nutr…
May 5, 2015
The 4R Nutrient Stewardship Certification Program has announced that all four of Sunrise Cooperative Inc.’s agronomy branches, located in Attica, Read More
Crop InputsSyngenta Scientist Named 2015 National Inventors Hall O…
May 5, 2015
The National Inventors Hall of Fame (NIHF) announced its 2015 class of inductees. Among the 14 honored is scientist Mary-Dell Read More
Eric SfiligojIARC Glyphosate Report: A Closer Look At ‘Probabl…
May 5, 2015
By now, you’ve probably run across a story or two (probably closer to 100) detailing the ongoing controversy over the Read More
Syngenta
Eric SfiligojWill Monsanto And Syngenta Combine This Time?
May 4, 2015
Under the heading of “never say never,” it sounds as if crop protection/seed giants Monsanto Co. and Syngenta are once Read More
Dr. Bryan Young, Southern Illinois University, shows tour attendees a female Palmer amaranth plant.
Crop InputsPurdue Weed Scientist Publishes Weed Resistance White P…
May 4, 2015
Resistant weeds, the appropriate use of herbicides and integrated weed management strategies are highlighted topics in the new white paper, Read More
Industry NewsMonsanto-Syngenta Mega-Merger Would Drive More Deals
May 4, 2015
A combination of Monsanto Co. and Syngenta AG would set the stage for even more mergers and acquisitions, reports Brooke Read More
InsecticidesAgrian Announces New California Feature
May 4, 2015
Agrian announced today that it has developed a feature within its recommendation writing program that will support the California Department Read More
Storage Tanks at Nachurs
FertilizerNachurs Alpine Solutions: Liquid Fertilizer With Precis…
May 4, 2015
When it comes to fertilizer options in 2015 and beyond, ag retailers are taking a long, hard look at liquid. Read More
West Central Sac City growers
StewardshipIowa Lawsuit Challenges Ag’s Water Quality Efforts
May 3, 2015
Nutrient problems in west-central Iowa’s water supply made national headlines in March when the Des Moines Water Works (DMWW) filed Read More
Tim Hassinger Dow AgroSciences President and CEO
Crop InputsDow AgroSciences: Always About Agriculture
May 2, 2015
When you consider their respective backgrounds, it’s little wonder why Dow AgroSciences and new President/CEO Tim Hassinger ended up together. Read More
Nozzle spray close-up
AdjuvantsSpray Drift Enters More Complex Era
May 1, 2015
Off-target movement of crop protection products has been a problem for decades. The issue got more contentious when glyphosate-tolerant crops Read More
Crop InputsTop 10 Twitter Pics For #Plant15
April 30, 2015
Growers and ag retailers are working feverishly to plant this year’s crop. Fortunately, many of them still have time to Read More
ManagementIowa Retailer Sticks Up For Agriculture and New Spray D…
April 30, 2015
Paul Schrimpf and Eric Sfiligoj talk about how one Iowa ag retailer is working to defend agricultural practices and an Read More