The Soybean Watch ’17 field didn’t escape problems with slugs. Many fields across the Midwest battled the slimy creatures. Unless you scouted closely early and identified the cause of lost plants, you may be scratching your head at harvest.

Steve Gauck, sales agronomist for Beck’s based near Greensburg, Ind., says he fielded calls about slugs in soybeans into early summer.

Soybean Watch ’17 is sponsored by Beck’s, Atlanta, Ind. Farm Progress interviewed Gauck just after he inspected the Soybean Watch ’17 field in central Indiana around July 1.

Slugs have done their damage and are gone, correct? They should have been gone weeks ago. Because of cooler, wetter weather patterns, they persisted. Typically when the soil warms up, you don’t find them anymore. However, I found one actual slug yet this morning. These soybeans were planted June 6, and were in the V2 to V3 stage.

If the slugs are gone, for the most part, why talk about them now? It’s an opportunity to learn. I suspect many people looked at their fields from the road, assumed they looked good and drove on. If you walked out and scouted, you soon found the stand wasn’t as good as you thought. In many cases, seedlings were destroyed by slugs. It’s a possible reason for thin stands that you can’t diagnose in August. 

Do some fields with slug damage still have the opportunity for good yields? Absolutely! It depends on the weather during the rest of the season. Many plants were destroyed in some fields, but many survived and branched out. I did a couple stand counts on my initial visit to the field, counting plants within 1/1,000 acre. At one of the thinner locations, I found around 82,000 plants per acre. At another spot I found 106,000 plants per acre. I’m perfectly fine with 80,000 plants per acre in 15-inch rows as long as the stand is consistent, without big gaps — and for the most part, it was consistent. I consider a stand of 100,000 plants a good stand.

Why were slugs such a problem this year? It was primarily weather-related. The spring turned cool and wet, and plants had trouble outgrowing the slugs. Slugs hung around much longer than normal. They tended to be worse where soybeans were planted into heavy residue. It stayed cooler under the residue. Even within the Soybean Watch ’17 field, no-tilled at an angle into cornstalks, there were more plants with feeding damage where the soybean row fell into the old corn row.

So should growers abandon no-till next year for fear of slug issues? No. This was one of the worst slug outbreaks in a long time. Next year could be totally different. The problem this year was tied very closely to spring weather patterns. Yes, tillage may help lessen the odds of slug problems. But if you have good reasons for no-tilling soybeans, I wouldn’t let one bad year with slugs dictate major changes in how I farm. 

Check out the slideshow to see some slug damage in the field.