Slow-growing crops vulnerable to slugs

COLUMBUS – Recent rains and cool temperatures have slowed crop growth across Ohio and Indiana, leaving newly emerging plants and yet-to-be-planted fields vulnerable to slug feeding, said entomologist Ron Hammond, Ohio State University.

As slug problems begin to be reported from around the state, the question is whether the damage will equal last years’, which was “extremely bad” in Ohio, Hammond said. It remains to be seen if the slowly developing crops can outgrow slug feeding, which can result in stand loss or stunting.

A common misconception is that cool, wet conditions cause slug problems. Slugs are a problem because plants don’t grow well in cool, wet weather, while the slugs would be there anyway. Last year’s combination of warm, dry conditions, early planting and an early slug hatch led to the worst feeding in Hammond’s recent memory.

“By this same time last year, we saw lots of problems,” said Hammond.

Potential problems.

No-till fields should be closely watched due to reports of problems around the state combined with the cooler weather, Hammond said. Farmers should expect slugs to continue to grow and become potential problems through mid-to-late June. Also at risk are no-till fields that remain to be planted because of the rain delay, Hammond said. Young slugs will be ready for feeding on the tender emerging plants.

“I would be very concerned with planting in late May and early June,” Hammond said. “The slugs might be there.”

No-till fields should be treated when it appears that young corn or soybean plants cannot replace foliage fast enough to keep up with slug feeding, Hammond said. These fields may appear to be stunted. A farmer’s goal is to control the slugs in time to stay ahead of their feeding, he said.

Treatments.

Always consider treatments when replanting fields where slugs reduced the prior stands, Hammond said. The slugs that attacked the first crop will likely be bigger and capable of even greater feeding, he said. The primary molluscicide for killing slugs is Deadline MPs broadcast at 10 pounds an acre. Because a treatment can cost $15-18 an acre, some farmers have used less-expensive solutions sprayed over plants, such as 28-percent nitrogen, with varied results.