LATE SOWN crops after sugar beet or potatoes could be at risk from slug damage this autumn and possibly into next spring, growers have been warned.

Mild autumn weather in many areas has favoured egg laying and also means field populations are high for the time of year, according to Jenna Willis from Rothamsted Research.

Model predictions suggest that while the peak population this season was lower than previous years, numbers could remain high until next January/February – possibly up to four times greater than the same period in 2005, she said.

“The problem is down to the high numbers of small juveniles and eggs we saw earlier in the autumn. If the model holds true, crops will still be a threat well into the New Year.”

But a few days frost can kill adult slugs, she noted. “If we get a dry, frosty winter, potential slug numbers may never actually come through. However, snow is likely to favour slugs as it insulates the soil.”

Cambridgeshire-based agronomist, Dick Neale agreed that slug numbers had been high in many fields this autumn, but said most well developed crops sown into good seedbeds should now be clear of danger.

“Late-sown and backward crops will still need careful monitoring. Even where pellets have been applied, slugs will have found plenty of alternative food sources, so numbers could still be very high,” he added.

Growers need to be careful when choosing pellets for winter use, as many break down in wet and frosty conditions, he said. He suggests using pasta-based pellets such as Clartex.