Early Sampling Key to Better Slug Management

WOOSTER, Ohio — As the saying goes, “To defeat the enemy, one must know the enemy.” For Ohio no-till growers, the first step towards slug control is knowing what they may be up against during the growing season. Ron Hammond, an Ohio State University research entomologist with the Ohio Agricultural Research and Development Center, said that sampling fields for populations in early spring is the key to any kind of slug management program. “Growers should be out in their fields in March and April to see what’s out there, especially in those fields that have had a history of slug problems,” said Hammond. “They have to know ahead of time what they will be facing.” The juvenile stage of the slug creates the most damage to crops and its voracious appetite and large densities can be devastating for farmers who have had a history of slug problems. Upon hatching in early to mid-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. Keeping a close eye on fields early on is just one tactic in an overall Integrated Pest Management approach to effectively manage the slug. “Fields with a lot of eggs should be planted as quickly as possible. The quicker the plants are planted, the quicker they germinate and the better off a grower will be,” said Hammond. Other management practices include tilling where applicable, applying techniques to boost plant production and using treatments where warranted during the growing season. “With corn, since it’s often 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.” Some growers throughout a six-county area in Ohio are participating in a Natural Resources Conservation Services-funded program this spring to determine how effective the IPM approach will be, through scouting, treatment and evaluation. The three-year Environmental Quality Incentives Program (EQIP) is designed to not only help growers control slugs in no-till fields, but also protect soil and water quality and provide information on controlling future slug infestations. “Everyone is concerned about what damage slugs are doing,” said Hammond. “It’s the one thing that can keep someone out of no-till.” Growers from Wayne, Richland, Ashland, Holmes, Licking and Knox counties are participating in the EQIP program.