Initial reports of suspected dicamba damage have been received this week by Stine Seed Company agronomists, marking yet another year of issues with cupped soybeans.
“Growers are starting to see some soybeans that look cupped,” says Dustin Ellis, regional sales agronomist for Stine. “Tis’ the season, you could say. I think farmers are starting to realize what the injury looks like, and they know what’s causing it.”
Increased use of various forms of dicamba has created issues for both farmers and non-farmers. The requirements needed to safely apply this herbicide in soybeans make timely and effective application difficult and present a significant amount of risk to both growers and applicators.
As the national deadline (June 30) for spraying dicamba has passed, growers who planted susceptible soybeans need to watch for early symptoms of dicamba crossover in their fields.
“Typically, over the Fourth of July weekend, growers are out looking at their fields,” Ellis says. “I have a feeling we’ll hear a lot more reports.
What to watch
Dicamba-related injury typically appears during the vegetative stages and on new plant growth. Growers may notice leaf drop or twisting at the stem in some instances, but the major indicator of dicamba injury is cupped leaves, which are typically found in the newer leaf growth and can be somewhat cream or discolored in appearance.
“Minor injury may appear as wrinkling of the leaf that’s very consistent across all three trifoliate leaflets of an individual leaf,” says ISU Extension Field Agronomist Meaghan Anderson. “Each trifoliate of the leaflet will be affected very similarly, almost mirroring one another.
Anderson notes that the most likely injury being confused with dicamba is from HG15 products applied to soybeans. Those applications, she says, may result in a drawstring effect or crinkling of leaf edges on the next leaf or two that develop after application.
Meaghan debunks reports that environmental response, response to stress, or response to other herbicides, such as Liberty® and ammonium sulfate in spray mixes, could cause this damage.
“We very rarely would see this kind of damage prior to six years ago, so it’s pretty easy to dispel many of those myths regarding the sensitivity of certain soybeans to other factors that may result in cupping,” says Anderson. “I’ve never seen any other research (or factor) that causes cupped leaves that occur only in the middle of the summer and only in non-dicamba soybeans. It’s just simply not true.”
For additional insight about dicamba from Anderson listen to episode 5 of the Stine Seedcast.
Free dicamba damage testing for customers
At Stine, we believe soybean growers need as many options as possible to achieve sound and effective weed control, and we remain committed to offering our customers a multitude of options, all packaged in high-yielding genetics. We are confident in the yield potential of the dicamba-enabled soybean genetics that we offer to our customers.
However, given the uncertainty that remains about the long-term viability of dicamba as a soybean weed control solution, we want our grower customers to understand that alternative options are available and that we will assist in any way we can to ensure your fields are positioned for success now and in the future.
To assist our grower customers who are experiencing dicamba damage to their fields, Stine is offering to pay the cost of dicamba testing for suspected damage now through August 1, 2022.
The testing program administered during the 2021 growing season, processed 322 total dicamba test samples, representing 16 states. Of those tests, 239 (75%) tested positive for the presence of dicamba.
“During the past few years there have been lots of excuses floated for why we keep seeing cupped soybeans occurring,” says David Thompson, national sales and marketing director. “At Stine, we decided that the best approach is not to guess but to test. That’s why we chose to offer free dicamba testing to our customers in 2021 and why we are again offering this program.”
Growers who want to utilize this offer need to contact their Stine independent sales representative (ISR) or regional sales agronomist (RSA) who will collect the sample(s) and submit them to the designated testing entity. For each sample submitted, Stine will cover the cost of testing for dicamba presence. The Stine RSA will receive a copy of the test results to be shared with the customer.
“We are here to do whatever we need to do to help you with whatever situation you have,” says Ellis. “We can help scout, test or advise.”
If you’re unsure who your local Stine ISR or RSA is, use our Find Stine tool or contact us directly at (515) 677-2605.