Effective control needed to suppress burgeoning slug population

With soil moisture levels high this summer, growers must use good quality slug pellets applied accurately to control burgeoning slug populations.

That is the advice from Adama molluscicides technical specialist Andy Bailey, who says equipment must be properly calibrated to ensure accurate pellet application.

“Wet conditions throughout much of June and July have provided ideal conditions for an extended breeding window for slugs which means populations are already high, with reports of attacks on young oilseed rape crops coming in thick and fast.

“In those parts of the UK where the unsettled weather has continued into August, slug populations could be even greater, making it all the more vital for growers to apply good quality slug bait on time and accurately.”

Growers are reminded that molluscicides should only be used once populations have reached the appropriate damage-risk threshold per trapping point – and only if weather conditions are favourable.

“Applying slug pellets immediately prior to heavy rainfall can lead to their rapid degradation, especially if the pellets are of a poorer quality,” says Mr Bailey.

Threshold point

“Regular assessments to evaluate slug populations is the way to go, with spreading equipment calibrated and ready to be deployed as soon as the threshold point has been reached and a period of favourable, settled weather prevails.”

The National Sprayer Testing Scheme says applicators should be calibrated in line with the manufacturer’s recommendations before they are used and then during the season.

“Pellet spreaders and spinners should be positioned at an appropriate height for the machine on which they are mounted – typically 110cm above the ground for quad-mounted applicators,” says Mr Bailey.

“They should also be operated at a sensible forward operating speed of around 12kph to ensure slug pellets are applied evenly and consistently across the spreading width.”