Rising slug numbers threaten emerging crops

Slug numbers are rising following the recent rain and farmers are being advised to control numbers where necessary, to avoid newly emerging crops being eaten.

Increasing numbers of slugs are being reported in various parts of the UK and agronomists are anticipating a moderate-to-high slug pressure season.

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Certis’s technical specialist, Geoffrey Bastard, said that growers should not be complacent even though little straw has been left after harvest and dry summer conditions have helped to keep slugs at bay.

“We’ve seen slugs grazing on stubble and oilseed rape volunteers following harvest, particularly in places where there’s been significant rainfall, and where soils are heavier,” he said.

Integrated approach

Mr Bastard advises growers to adopt an integrated approach, which includes a combination of control methods to prepare for a potential influx of the pests.

“Particular attention should be paid to fields with historically high slug pressure,” he said.

“Previous crop and soil type will also have an impact – for example, wheat after oilseed rape will be particularly susceptible.”

He added that slug pressure should be frequently monitored on a field-by-field basis. “Assess the current in-field populations and ensure soils are well consolidated ahead of drilling.

“However, I’d be cautious of cultivating too early, as working dry and cracked soils could cause more damage to the soil structure. This can slow down germination and negatively impact on the crop successfully growing away from the pest.”

Monitoring slugs

He also recommended slug trapping to determine when slug pellets are required.

“Monitor populations by placing slug traps with layers mash underneath,” he said.

“Put traps out in the evening to be checked early the following morning. If you see four or more slugs, slug pellets should be applied.