The slug problem
Slugs belong to the mollusc family and are closely related to snails. The three most common slugs in UK field crops; common keeled slug, garden slug and grey field slug. Grey field slugs (Deroceras reticulatum) are more widespread and common amongst field crops, causing the majority of damage.
Slug species are able to rapidly reproduce without a mate present, laying up to 500 eggs in a life time of between 6 to 18 months. These eggs are often laid in damp, dark areas in crevices and under debris. Therefore the rate of multiplication is very fast and high.
Conditions favouring and promoting slugs
Moisture and temperature are the two most influential factors. Cool, wet conditions are favoured by slugs in order to thrive. Hence mild and wet spring/autumn conditions provide ideal conditions. Even in a dry season slugs can quickly repopulate and thrive at the first arrival of rain.
Crop type - previous cropping and cover crops can all have an effect on slug populations
Soil type and drainage with water retaining soils like clays and silts, and poorly draining soils providing higher moisture levels.
Cultivation method has an effect with direct drilling, delayed drilling dates, little soil disturbance (no till) all providing good conditions for slug populations.
Crop residues, organic matter and weeds will provide cover and protection for slugs.
Nearby hedges, wasteland and ditches are refuge areas for slugs to migrate from into cropped areas
Impact of slugs
Slugs can cause significant effects on early crop establishment stages, particularly in oilseed rape and winter cereals. Reduction in the plant population has direct impact on the yield potential of the crop.
In potatoes, slug damage can result in slow tuber growth as well as a prolonged period of vulnerability during crop establishment. Later in the season slugs cause economic loss by damaging the daughter tubers prior to harvest.
The initial damage from slugs can also have a knock on effect of leading to a higher risk of damage from other pests since the crop vigour is reduced and ability to cope with further damage is lessened.
In vegetable crops as well as reducing establishment and damaging the harvestable yield of plants, slugs can also become a contaminant in the packed produce, leading to rejection by consumers and retailers.
Understanding slug pressure on an individual farm basis is essential and taking an integrated approach is key.
Knowing your predominant weather patterns, soil types, field history, crop rotation, cultivations and establishment methods are key starting points when planning how to tackle slugs.
Fine consolidated seed beds minimise slug movement and their ability to reach germinating seeds, along with consideration of drilling depth
Slug monitoring is essential to understand what is happening at field level. This can be supported with decision support tools such as the SlugWatch App (available on iOS and Android)
Slugs tend to feed at night and so using slug matts for monitoring provides a refuge for slugs when it comes to assessing them early the following morning
Monitor oilseed rape and cereals from sowing and cereals. Potatoes have two critical periods at 50% and 75% canopy closure at the early stages of tuber bulking and making sure to monitor the crop until desiccation
Treat with Sluxx-HP if required when thresholds are reached. Continue to monitor and keep records of slug numbers and treatments made
Download our SlugWatch app to measure slug pressure in your area.
The app provides the opportunity to view location-specific slug activity data, along with information on weather conditions, helping you to make informed decisions on slug monitoring and applying slug pellets.
Available to download for Android and IOS
'Get Pelletwise’ is the campaign of the Metaldehyde Stewardship Group (MSG).
The group’s aim is to promote and encourage best practice with metaldehyde slug pellets, amongst agricultural users.
Slug Behaviour Trial
Regional technical specialist Geoffrey Bastard along with Professor Keith Walters of Harper Adams University explain how we investigated the behaviour of slugs once they have ingested ferric phosphate pellets.
This video is presented by Andy Alexander, it considers the use and benefits of using Ferric Phosphate slug pellets on potato crops.
A new generation moluscicide
High quality pasta based pellets, excellent efficacy, no buffer zone required, no environmental restriction, low impact on non-target organisms