Don't Let Slugs Rule the Roost in No-Till Fields

February 5, 2002

WOOSTER, Ohio - In the battle against slugs, a sharp eye and savvy management tactics may mean the difference between a damaged crop and successful yields for no-till farmers.

"Growers need to be aware of what's going on in their fields. They should know from year to year what their field history is and from that information determine how soon they should plant and whether to use a molluscicide," said Ohio State University entomologist Ron Hammond. "The first thing growers need to do if they have a slug problem is to acknowledge that problem. That's half the battle." Hammond will be on hand at the Conservation Tillage and Technology Conference, Feb. 25-26 in Ada, Ohio, to discuss slug management - what kinds of slugs are most commonly found in the mid-west, their life cycle and the most effective ways of controlling them. Slugs are problematic in no-till fields because the residue that is left behind creates a habitat for the arthropods to flourish.

"You won't find the problems associated with slugs in conventional farming as you would in no-till. The residue in no-till that cuts down on soil and water loss, helps the retention of organic material, is the same thing that provides shelter for the slugs," said Hammond, a researcher for the Ohio Agricultural Research and Development Center (OARDC). "Slugs have caused people to abandon no-till practices in some fields, which is what we are trying to prevent." The juvenile stage of the slug creates the most damage to crops and its voracious appetite can be devastating for farmers who have had a history of slug problems. Upon hatching in mid-to-late May, the slug will begin feeding on anything that is planted in the field, whether it's corn, soybeans or alfalfa. Slug feeding can cause significant reductions in corn yields and total stand loss in soybeans.

"With corn, since it's planted early enough before the eggs hatch, the crop gets out of the ground in most cases. But I've seen corn in the two-three leaf stages with slug populations so heavy in the field that there was a 50-75 percent yield reduction," said Hammond. "Soybeans are more of a problem because they are often planted later in the season around the time of egg hatching. Slugs can literally take those plants out before a grower even sees them and there will be a 100 percent stand reduction. Then a grower has to go back and replant maybe two or even three times to get a crop." One of the more successful management strategies in controlling slugs in soybean fields where egg numbers or slug populations are high might be to apply molluscicides during planting. "In 2000, we had a grower that had lost his entire field to slugs. So upon replanting we treated part of the field with a molluscicide and another part of the field we left as is," said Hammond. "The treated portion of the field had a good stand and the non-treated field was lost and needed to be replanted a third time. So growers may want to consider putting on an application to prevent that stand loss in soybeans." Deadline MPs molluscicide has proven to be an effective chemical in treating slug populations. New products will be introduced at the tillage conference that have proven to be just as effective and may be less costly for the grower.

Hammond also encourages farmers to consider planting early if weather conditions are favorable and other insects and diseases are not problematic. "If a grower can get his crop in the ground before the eggs hatch, then when the slugs start feeding the plants may be big enough to where the feeding may not cause as much damage," he said. "Anything a grower can do to boost the growth of that plant will help the situation." Over 50 speakers from land-grant universities, the farming sector and agricultural industries and organizations will be speaking at the two-day tillage conference. The program will cover a wide range of topics including agriculture-related panel discussions, strip till research, weed and pest management, soil fertility, GMO crops, value-added farming, crop consulting, soil and water quality issues, precision agriculture and producer programs.

The tillage conference is being sponsored by Ohio State University Extension, Northwest Ohio Soil and Water Conservation Districts, United States Department of Agriculture Natural Resources Conservation Service, USDA Farm Service Agency and the Ohio No-Till Council.

Early registration is $20 per day or $30 to attend both days. Registration after Feb. 11 is $30 a day or $40 for both days. For a copy of the agenda, registration information, or directions to Ohio Northern University, contact the Hancock County Ohio State Extension office at (419) 422-3851 or the Allen County Soil and Water Conservation District at (419) 223-0040.

Author(s): 
Candace Pollock
Source(s): 
Ron Hammond