Slug control is an almost constant headache for many vegetable and salad producers, with one solitary slug capable of consuming two entire lettuces in its lifetime. David Morris, of Golden Plain Ltd explains how he keeps one step ahead of the menacing molluscs. David is responsible for 300 hectares of Romaine, Little Gem and Iceberg lettuce in West Sussex. “Slugs are a horrendous problem. They’re one of my biggest issues,” he says. “I have tried every different approach possible,” says David, commenting on the complex task he has to contend when planning slug pellet applications. “In some fields we have networks of footpaths as well as bordering watercourses, reservoirs, bore holes and irrigation ponds to consider as well as plenty of hedgerows and headlands. The environmental characteristics of our slug control strategies are just as important as the efficacy and control. “Add to that, the increasingly stringent protocol requirements restricting the use of methiocarb and metaldehyde and we’ve got a challenging slug control problem,” he says. Such is the magnitude of the issue, David is already underway with planning his 2011 slug control strategy as this season’s treatments are being applied. “We’re trapping in the wheat fields that are due to have next year’s lettuce crop. We will trap throughout the season, and in those fields with a known slug history, we apply slug pellets along with the spring sprays – and that’s before the lettuce gets anywhere near the land,” explains David. “Depending on the situation at risk fields receive either ferric phosphate or metaldehyde applications. Applied to headlands and around the more vulnerable areas in particular, Sluxx (ferric phosphate) is considered useful in providing very low toxicity to all non-target organisms with a perfect fit alongside the use of metaldehyde. “We’re able to broadcast at between 2 and 24 metre widths which helps us optimise our use of the actives.” David has previously had good results with Ferramol. “But Sluxx – a higher three-per-cent formulation – gives us even more clout with the retained environmental credentials,” he comments. Cultivation practices also have an important role to play. “We cultivate two or three times, incorporating the cereal stubbles as soon as the wheat crop is off. This gives the birds a chance to get at the slugs.” Pellet applications then occur a week before lettuce planting begins with Sluxx applied at 6kg/ha. Growers should note that the maximum label rate for Sluxx permits/advises applications at the 7kg/ha rate. “Then two or three days before planting we rotavate the land to prepare the beds – which also gives a degree of slug control too. “A week after planting, depending on the situation, we treat again using ferric phosphate at 4kg/ha alongside metaldehyde applications. We won’t apply pellets immediately after planting as it takes three or four days for the slugs to work their way through the soil profile after the land has been turned over,” he explains. David explains that it's impossible to broadcast pellets after the rosette stage. "It's just not worth te risk of a slug pellet bouncing into the lettuce head. So we've switched to inter-row pellet applications of Sluxx from this stage through to harvest. We apply at 4kg/ha and its a good attractant, crucially enticing the slugs away from the lettuce and giving an excellent kill rate," notes David. |