20 May 1998
Fighting the slug menace

Question

BESIDES having to catch up on all the field operations delayed by the relentless rain, many growers can expect a legacy of slugs to contend with. Whats their best strategy?

Response

Dr Bill Lankford, Rhone-Poulenc, Essex

Answer

SLUGS are thriving, both in fields already planted with potatoes and those destined for planting once soils dry out.

Not just the heavy rainfall, but also warm air and soil conditions, have contributed to record numbers of slugs this year. Even growers who carried out extra seedbed cultivations to try to keep them in check report very high populations.

Obviously growers need to be on guard and use traps to confirm their activity. Hardboard traps – 40cm2 – baited with poultry layers meal and spaced at one per hectare are a good indicator.

An alternative technique after planting is to place upturned flower pot saucers, again containing layers mash, between the ridges.

If slugs are actively foraging near the surface, they will accumulate under the baited traps within 24 hours.

Applying slug pellets to coincide with periods of activity around planting time can contribute up to 50% of the overall control gained from a molluscicide programme, reducing the potential for further breeding and tuber damage from juveniles in the summer.