ROCKVILLE, Md. (DTN) -- With seed treatment use on the rise, farmers and regulators are becoming hard-pressed to keep track of the rising number of pesticide ingredients added to seeds before planting.
As companies bundle more active ingredients together and treat seeds farther upstream from the farm, growers' knowledge of their personal on-farm pesticide inputs is becoming less accurate, a new study found. And they're not alone -- U.S. regulators don't have good data on how many pesticides are used in seed treatments, either.
The result is that many farmers may be using more pesticides than they realized -- and perhaps more than they need -- at a time when profit margins are slim and uncertain.
WHAT'S ON YOUR SEED?
Most seed treatments consist of a fungicide, insecticide, nematicide, plant growth regulator, biologicals or some combination of those.
Scientists at the University of Wisconsin have created a single chart, updated yearly, that breaks down the active ingredients of most commercially available seed treatments.
See it here: https://ipcm.wisc.edu/…
Seed treatment products can hold anywhere from one active ingredient up to six or more. Companies often offer the same active ingredient or mix of active ingredients under different brand names, which can create confusion.
For example, the Wisconsin researchers document 143 different seed treatment products, but only about 40 unique active ingredients. Just one active ingredient, the common fungicide metalaxyl, is sold under 11 different brand names.
So it's not surprising that farmers could be confused about what pesticides they're using each year. A group of federal, private and academic scientists recently analyzed private and government survey data and found that many growers struggled to identify which insecticides or fungicides they applied via seed treatments to their acres.
In the study, published in a journal called BioScience, researchers found that 16% of the responding cotton growers, 35% of corn growers, 38% of the soybean growers, 43% of winter wheat growers and 57% of spring wheat growers were unable to provide the name of the seed treatment product used on their crops.
In contrast, these farmers were readily able to provide the names of pesticides they applied to fields later in the season, by air or sprayer, 97% to 99% of the time.
The farther the seed treatment application moved away from the farmer's field, the less knowledge growers had, the survey data showed.
For example, of the 64% of soybean farmers using seed treatments, approximately 88% indicated that they purchased pre-treated seeds from a seed company. The 12% who applied a treatment after purchase were nearly twice as likely to know what was on their seed.
The industry trend toward bundling more seed treatment active ingredients into single products in the past decade may actually be pushing farmers to use more pesticides than they want or need, the researchers noted.
For example, the study found that 19% of surveyed cotton growers in 2015 assumed that their seed did not contain a fungicide, when the product they used actually did.
"The biggest takeaway is that farmers know less about their pesticides applied to the seed than pesticides applied in other ways on their farm," said Paul Esker, a Penn State plant pathologist and epidemiologist who participated in the study. "What we're seeing is that the selection process for seed treatments has become very tied up in the seed genetics you want, and less related to the actual conditions on your farm."
REGULATORS IN THE DARK, TOO
Farmers shouldn't feel too bad about this confusion. Even U.S. regulatory agencies don't have a good handle on the extent of pesticides used in seed treatments.
Technically, USDA is required to track pesticide use by the Food Quality Protection Act. But EPA, the agency in charge of registering pesticides, doesn't track pesticides used in seed treatments.
At issue is a 1988 amendment made to the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), EPA's governing law, which exempts "pesticide-treated articles," such as pesticide-coated railroad ties, from EPA's labeling and registration requirements.
Both the federal agency and agrichemical companies have interpreted that amendment to include pesticide-coated seed. As a result, there is a dearth of publically available data on seed treatment pesticide use. A global marketing and research company, Kynetec, briefly filled the gap by collecting seed treatment survey data starting in 2004. But as farmers became increasingly less certain of what exact product and ingredients were used on their seed, the company began expending more and more resources to verify their responses, before eventually abandoning the data collection altogether in 2014, researchers reported in the BioScience study.
USDA's Economic Research Service then started adding seed treatment questions to its regular Agricultural Resource Management Survey (ARMS) in 2015. But the agency does not attempt to verify the responses, which makes their estimates less reliable, Esker noted.
Altogether, the Kynetec data, USDA data and some state datasets show a rapid rise in the use of treated seed since the early 2000's. Overall, the BioScience researchers estimated that from 2012 through 2014, approximately 90% of corn, 76% of soybean, 62% of cotton, and 56% of winter wheat acres in the U.S. were planted with treated seed.
"But a key point here is that, because of this lack of information, we're not able to capture the true reality of seed treatment use," Esker cautioned.
WHY YOU SHOULD KNOW
Even though treated seeds contain only small amounts of fungicides and insecticides, their use is so prevalent that it adds up quickly.
For example, a previous study by Penn State researchers found that seeds treated with a neonicotinoid insecticide accounted for 43% of total insecticide use in corn, around 22% in soybeans and around 27% in wheat between 2010 and 2012.
This widespread, default use of certain pesticides, such as neonicotinoids, is concerning for not only environmental reasons, but also for profitability and resistance concerns, the BioScience researchers concluded.
"The result is that farmers may be unwittingly paying for a (pesticide) they do not want or need, which may also entail consequences for the environment," they wrote. "The overuse of pesticides and farmers' lack of knowledge about the pesticides coated on their seeds can therefore negatively affect worker safety during seed handling and planting, the environment, pest resistance management, and farm economics."
Seed treatments can be very effective against certain soil-dwelling and early season insect pests and diseases, and many farmers like using them as an insurance policy, Esker noted.
But scientists increasingly agree that not all growers need them. In particular, there is a growing consensus among university entomologists and plant pathologists in the Midwest, Southeast and Mid-Atlantic regions that soybean growers there do not see reliable and consistent yield returns from either fungicide or insecticide soybean seed treatments.
See the latest DTN story on that here: https://www.dtnpf.com/…
Companies are reluctant to share the exact cost of individual seed treatment products and often tie their use to free replant insurance, which incentivizes their use, although it can vary in value from year to year.
See the DTN story here: https://www.dtnpf.com/…
As a result, it can be hard for farmers to know the exact monetary value of their seed treatments, and thus determine if they're worth it, Esker said.
Regardless, the first step to knowing if you want these pesticides used on your farm is knowing what exactly you're using, which was the BioScience researchers goal all along, he said.
"We're trying to get that knowledge back into the hands of farmers," he said. "So they can make their own decisions about what seed treatment products they actually need on their farm."
See the BioScience article here: https://academic.oup.com/…
See the University of Wisconsin seed treatment chart again here: https://ipcm.wisc.edu/…
Emily Unglesbee can be reached at Emily.email@example.com
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