Keeping metaldehyde out of surface water has been a top priority for advisers making slug pellet recommendations, and for farmers and operators making diligent applications of the pesticide over the last two years, but it’s a trend which must continue as the current wet weather stimulates slug activity.
According to the Metaldehyde Stewardship Group’s (MSG’s) Colin Myram the actions taken by individuals to date are worthy of congratulation. “We are continuing to show that we can keep metaldehyde out of water,” says Colin.
“Data sourced from the water companies has revealed that levels of metaldehyde in raw water have, for the third year in a row now, been in decline overall,” he reports.
“But the hose pipe bans in place in the south and east of the country are testament to the very dry autumn and winter conditions experienced last year and the season before that have meant reduced quantities of slug pellets have been applied,” he notes.
“We must not to be complacent this season in our pelleting practices,” urges Colin. Keeping within the dose rate guidelines set out by the MSG, and continuing the adoption of best practice advice to prevent direct contamination and miss-application is a must, he believes.
Even last autumn, with low slug pellet usage, some exceedances were reported. “Albeit at very low levels and short lived, there were instance of metaldehyde detections inYorkshireandScotland, areas of typically higher rainfall.”
Colin is warning that the recent extreme weather conditions – the wet fields and prolonged moisture – is ideal for slug development. “It is likely that we will see numbers increase.
“Despite the prolonged dry conditions before the recent wet weather, slugs will have remained deep in the soil profile. And now they will be coming up to the surface to feed and breed.”
Colin notes that already there have been reports of slug damage in sugar beet. “And with one slug capable of producing 100 eggs – numbers could very rapidly build up,” he warns.
Colin is advising that growers think now about their molluscicide strategy for the year ahead. “Especially those with potatoes in the rotation requiring treatment over the coming weeks.
“With 700g of metaldehyde/ha permitted per calendar year (now a statutory requirement), growers need to ensure they are not using all of their metaldehyde allowance in their potato crop during June and July, particularly if this season presents a severe slug threat. Those planning to follow with a cereal crop, could soon reach and exceed the advised limits.” he says.
“We need growers to continue in their efforts and ensure no more metaldehyde than necessary is being used this season to ensure protection of water is sustained.”