Published on Monday, June 5, 2017
I feel like this year has been a big set up. We had excellent planting conditions in late March and early April, and we were able to get a lot of crops planted. Then Mother Nature took a turn for the worst, and the following three weeks were cold, wet, and cloudy. Much of our corn struggled to emerge and lacked the early season vigor I would typically like to see. However, we were only accumulating five to ten growing degree units (GDUs) per day, so it was somewhat expected. Seed treated with Beck’s Escalate™ yield enhancement system really had an advantage this year! Now that the weather has warmed up and we’ve started seeing the sun again, the corn that wasn’t underwater for too long is starting to look much better. Most of my service calls recently have been in regards to soybeans, or really the lack thereof. Even though each field has the potential to be completely different, I have started to notice a pattern. There have been two major culprits of soybean loss this year: PPO or Group 14 herbicides (especially in soybeans that were treated with ILeVo®) and slugs.
PPO’s are very effective on problematic weeds such as marestail, Palmer amaranth, and waterhemp, and are used on many acres across our marketing area. However, this control sometimes comes at a cost… as you could experience burnt hypocotyls and/or burnt growing points. When temperatures drop to the low 70’s or below and you experience cloudy or overcast days, a plants growth is slowed as is the speed at which the soybean can metabolize the herbicide. When this happens, the herbicide that would typically not hurt the soybean can begin to cause tissue damage and, in severe cases, cause plant mortality. ILeVo is an excellent seed treatment that can help protect soybeans against sudden death syndrome (SDS) and has even showed a yield increase in the absence of the disease. This year, Beck’s was able to offer this seed treatment at a very attractive price, and because of this, a lot of soybeans were treated. However, when you couple poor growing conditions with a PPO herbicide and an ILeVo seed treatment, this problem could compound itself, resulting in dead or injured soybeans.
The second major problem this year has been slug damage. This is an issue that I think will continue for years to come as a result of the amount of cover crops being planted. Slugs need wet conditions and ground residue to survive. Typically, they arrive in the fall and lay eggs which hatch in the spring and cause issues for us. Slugs are mainly a no-till problem, so if you use conventional-tillage, you shouldn’t have any problems. Poor growing conditions will slow the soybean down and leave it vulnerable for a longer period of time. Once, the soybean reaches VC, or the unifoliate emerges, it’s usually safe from plant death, but not foliar feeding. One of the hardest things about managing slugs is the fact that our typical insecticides (including seed treatments) have no effect on them. There are some slug baits on the market, but they’re expensive and hard to spread. However, you can employ some preventative measures to decrease the potential for damage. Some tips from local entomologists include planting in a prepared seed bed when good growing conditions are expected, using row cleaners to push residue away from the row, or using a minimum tillage implement to manage residue in the fall or early spring.
To summarize, the combination of PPO herbicides with ILeVo seed treatment and poor growing conditions have caused a lot of injury to emerging soybeans this year. In most cases, this damage has been cosmetic and not detrimental enough to warrant a replant. In most cases, the soybeans will grow out of the damage in 10 to 14 days with good growing conditions. Slugs have been the other concern in no-till fields with heavy ground residue. Early season growth has been slowed due to the cool weather, giving slugs an extended period to eat the seedling. In many cases, this has been severe enough to trigger supplemental planting throughout the field. Because our common insecticides have no activity on the slugs, management has been much more difficult. The key to managing slugs is to manage the residue that harbors them during the day.
If you have any questions, please contact your local Beck’s representative.
ILeVO® is a registered trademark of Bayer. Escalate™ is a trademark of Beck’s Superior Hybrids, Inc.
Author: Austin Scott
Categories: Agronomy, Kentucky, Tennessee, Field News