Remaining one step ahead of the slug challenge during autumn crop establishment is paramount, particularly following a year where most of the UK experienced unprecedented slug pressure.
Certis’ Product Manager Inez Cornell advises that 2012 saw a significant shift in slug pellet choice, with ferric phosphate taking over as the most widely used slug pellet after metaldehyde.
Ferric phosphate is the relative newcomer to the molluscicide market, but following last season it is now part of the mainstream having been recognised as an efficacious, environmentally sound alternative, especially in higher risk areas in close proximity to watercourses.
Many growers have gained confidence with ferric phosphate by building it into their integrated slug control programmes, as well as utilising traditional cultural control techniques. This allows growers to fully employ all the available tools in the battle against slug damage in vulnerable crops.
She recommends planning ahead and drawing confidence from the wealth of positive testimonials from those who put ferric phosphate to the ultimate test last year, and saw strong results.
Slug control case study: Mark Edgecombe, Velcourt Farm Manager at Woodsford Farms.
Farming in Dorset, Mark Edgecombe is a keen advocate of utilising integrated slug control measures to ensure he efficiently manages this pest challenge. Talking about the slug challenge in 2012, Mark explains how he targeted slugs on his autumn sown wheat crop.
“Our autumn sown wheat was drilled following oilseed rape in the rotation, leading to an increased risk of slug damage. So at planting in late September, we spread 3% metaldehyde slug pellets, off the back of our Vaderstad drill, at 6 metres intervals at 5kg/ha.”
Mark adds, “We were unable to get on to roll the field and utilise consolidation control techniques, so I was aware it was always going to be a challenging season from day one.“
He goes on to explain the level of risk, “It has been shown that one slug can eat up to 50 seedlings in the first week of crop establishment post drilling, and with our seed rate for autumn sown cereals being 300 seeds per square metre, we don’t need many slugs to end up with a patchy crop.
“It is an understatement that slugs have beaten us down,” he warns. “Even with utilising an early application of slug pellets following drilling, there were still signs of slug damage in terms of patches of poor establishment, and areas that had to be re drilled,” explains Mark.
Following the first application of pellets, Mark went on to apply Sluxx, containing ferric phosphate at 5kg/ha, which they found complimented the initial metaldehyde treatment.
Pellet choice is influenced by several factors, says Mark. “The number of baiting points per square metre is a key consideration to ensure we get the best possible level of coverage and control from a pellet. When applying like-for-like dose rates between metaldehyde and ferric phosphate, the increased bating points for Sluxx gave us enough cover to achieve good control.”
He adds, “Last autumn, when we had rain every couple of days, the main focus for me was the rainfastness of the pellets. This was one of the main reasons we switched to ferric phosphate, to try and combat the effects of the unpredictable weather and still maintain a level of slug control. Price and operator exposure are also factors I considered.”
“Our aim is not to achieve perfection, but as near as is practically possible in a real life farm scenario,” says Mark.
Concerns over water exceedances and certain actives also have a bearing on pellet choice. “We are fully aware that the River Frome, a SSSR, passes through our farm. This compounded our decision to switch to ferric phosphate on this farm, especially bearing in mind there are no environmental or buffer zone restrictions with Sluxx.”
To monitor slug activity, after having trapped slugs to assess treatment thresholds, Mark is aware that looking for carcasses and slime trails wouldn’t be a measure of efficiency for ferric phosphate pellets.
“My experience is, don’t be put off by the fact ferric phosphate doesn’t work in the same manner as other pellets – you don’t see the dead slugs or slime trails, but the product does work and is more flexible in terms of its rainfastness, and the ability to use the pellets in all scenarios.”
Integrated slug control measures utilising cultural controls are the mainstay for Woodsford Farm. “Ferric phosphate is going to be a key tool in our integrated slug control programme, and we plan to continue to use it in the future, not just in a year like last year where slug pressure was unprecedented,” concludes Mark.