The Disease/Insect Outlook for 2018: New Challenges at Every Turn
In recent years grower-customers’ annual fight against yield-robbing organisms has tended to focus on weeds. Meanwhile, crop diseases and insects continue to do their share of damage as well. In fact, according to Jared O’Connell, Global Marketing Manager for BASF, the estimated crop losses attributed to weeds worldwide is 13%. For diseases and insects, this figure tops 39%. “The global crop loss caused by arthropods equals $470 billion each year,” O’Connell, speaking at the 2018 Commodity Classic, said.
For 2018, industry insiders predict crop diseases will be particularly challenging. As always, reminds Dr. Eric Tedford, Technical Lead for Fungicides for Syngenta, disease pressures in any given year tie back to the dreaded “disease triangle” — environment/weather plus host plants plus pathogens present. “It’s very hard to predict the weather for each individual year, but there are some pathogens that are pretty predictable because they tend to happen every year,” Tedford says. “For corn, that’s gray leaf spot and Northern corn leaf blight. In soybeans, it’s always about frogeye leaf spot.”
Somewhat new for 2018, Tedford warns, soybean growers might be dealing with a severe outbreak of white mold. “White mold is a soil-borne disease that can devastate entire fields if left untreated,” he said. “During 2017, because of the milder summer and more rainfall, we saw some serious outbreaks of white mold in soybeans in the Upper Midwest, such as Iowa, South Dakota, and North Dakota.”
Also, ag retailers and their grower-customers will need to be on the lookout for disease resistance. In recent years pathogens, such as frogeye leaf spot, have developed resistance to strobilurin-based fungicides. “Fungicide resistance is a threat, and we should anticipate that resistant populations of plant diseases will increase over time with fungicide usage,” Troy Bettner, Marketing and Business Development Leader for HELM Agro US, says.
The Products to Help
To aid in efforts to combat crop diseases, crop protection suppliers are launching a host of new and improved products. One of the first is Helmstar Plus SC from HELM. According to James Whitehead, Agronomy Leader, Helmstar Plus SC provides two modes of action by combining the active ingredients tebuconazole and azoxystrobin to kill pathogen spores and act as an inhibitor. “This means it has excellent control on frogeye leaf spot and rust diseases,” Whitehead says.
Another product featuring two modes of action that can address frogeye leaf spot is DuPont’s Aproach Prima fungicide. Formulated with two active ingredients, picoxystrobin and cyproconazole, Aproach Prima can be used for disease control in corn, soybeans, and wheat. “In addition to frogeye leaf spot, Aproach Prima can be used to control brown spot in soybeans, gray leaf spot, and Northern leaf blight in corn, as well as leaf blotch and rust in wheat,” says Michael Meyer, North American Disease Management Technical Expert for the company.
Also available for the 2018 growing season is Delaro fungicide from Bayer CropScience. A combination of the active ingredients prothioconazole and trifloxystrobin, Delaro was the subject of 500 field trials in 20 states during the 2017 growing season. According to Randy Myers, Product Development Manager for Bayer, the new fungicide provided effective control against Northern corn leaf blight and Southern rust, as well as provided suppression against white mold in soybeans. “In tough market conditions, growers are looking to get the most out of their corn and soybean varieties,” Myers says. “These trials show that fungicides do more than just protect against disease.”
According to Syngenta’s Tedford, the company currently offers Trivapro fungicide (azoxystrobin+propiconazole+benzovindiflupyr) for these kinds of disease control in crops. However, the company is planning to launch a few new versions of its Miravis fungicide, featuring the active ingredient Adepidyn (pydiflumetofen), for the 2019 growing season. “Miravis Neo should be effective for the control of white mold in soybeans,” Tedford says. “Miravis Top should be good for controlling resistant frogeye leaf spot.”
Bugging the Bugs
In terms of insects and soil pests, one of the most damaging to soybean fields in recent years is the soybean cyst nematode (SCN). The microscopic roundworm, virtually invisible to the naked eye, is estimated to cause approximately $1.5 billion in crop damage each year across 30 U.S. states. And now, industry insiders say, resistance to control measures has begun to show up in SCN populations in certain areas of the country.
One of the products in the market in 2018 to combat SCN is Aveo EZ Nematicide from Valent U.S.A. Corp. A biological that offers featured bacillus amyloliquefaciens, Aveo EZ can serve as a stand-alone product for control or be paired with a fungicide agent as well, such as Intego, Thad Hayes, Seed Protection Business Manager for Valent, says.
In addition, according to Kelli Brown, North American Seed Applied Solutions Portfolio Manager for Monsanto, the company is planning to re-introduce NemaStrike into the market for 2018. “As you will remember, Monsanto decided to move cautiously with NemaStrike because of some handling concerns from customers,” Brown says. “But now we’ve conducted more due diligence on the product and will be rolling it out on a limited release basis to combat nematode issues.”
Another crop pest that does an incredible amount of financial damage to growers each year is corn rootworm. In fact, according to many experts, corn rootworm causes approximately $1 billion in lost revenue annually.
“Western corn rootworms are one of the most destructive corn pests in the U.S., taking a substantial toll on yields and profits through silk clipping and ineffective management costs,” Sally Feeley, Insecticide Product Manager for FMC Corp., says. Worse still, she adds, these insects are now showing signs of resistance to three major insecticide classes: organophosphates, carbamates, and pyrethroids.
For this reason, FMC has introduced Steward EC insecticide. Featuring the active ingredient indoxacarb, Steward EC works to control corn rootworms through ingestion as well as contact activity. “Basically, Steward EC affects the nervous system of the insect, which ultimately kills it,” Brent Neuberger, Senior Technical Sales Manager with FMC, says.
Another new product for rootworm control is Index from AMVAC. According to Neil DeStefano, Director, Portfolio and Marketing/eCommunication Management, Index features two different active ingredients (chlorethoxyfos+bifenthrin) to provide two different modes of action control and comes in a liquid vs. granular formulation. “Being a liquid gives growers more flexibility for use,” DeStefano says. “Index can be used to not only control rootworms but (also) seed-attacking pests, such as seed corn maggots, wireworms, and cutworms.”
A product that offers both disease and insect control is Tepera Plus from Arysta LifeScience. According to Lynn Justesen, Technical Sales Specialist, Row Crop Fungicides, Tepera Plus combines both fluoxastrobin to combat soil-borne diseases with bifenthrin to control rootworms, wireworms, and other insects.
Watching Soybean Aphids
Another insect experts warn will bear watching in 2018 and beyond is the soybean aphid. According to Ken Ostlie, an Entomologist at the University of Minnesota, this insect is beginning to show resistance to many insecticides, including organophosphates and pyrethroids. “We’ve gotten to this point because growers have tended to use only one or two modes of action products to control soybean aphids,” Ostlie says. “Insect issues weren’t very important in the late 1990s. But now that’s all changed.”
To help with fighting back against soybean aphids, BASF is getting ready to introduce a new insecticide to the market for the 2019 season. Called Inscalis, this insecticide features the active ingredient afidopyropen and has been shown to provide control against sucking insects, such as aphids, whiteflies, and psyllids. “In our testing, Inscalis can quickly stop feeding damage and pathogen transmission when used,” John Descary, Product Manager, Insecticide Strategy for BASF, says. “It also provides strong residual control.”