End of summer raises slug threat

The end of summer and forecasts of much-needed rain will be welcomed by growers hoping to achieve favourable plant populations ahead of winter, but with many crops yet to emerge growers are being urged to ensure crops are suitably protected from slugs.

“Drilling is progressing well across the country due to the run of dry weather, but for some crops germination has been slow and struggling for moisture.  The forecast for heavy rain in October will do much to help these young plants get going, but it will also bring populations of slugs to the surface in search of food,” warns Simon McMunn, Commercial Manager of slug pellet manufacturer De Sangosse.

“There is likely to be a period of several weeks before crops are past the critical stage and able to withstand attack during which time growers will need to apply pellets to provide protection,” he adds.

His comments are supported by independent expert David Glen of Styloma Research who warns that slugs will quickly resume typical activity once rain arrives.

“Growers should not be misled into thinking slugs numbers are low. They will have been buried deep in the soil profile during the summer, but they will be hungry and quickly become active once conditions suit,” says David Glen.

“Fine and firm seedbeds are the first defence against slug pressure, but as soil moisture levels rise and slugs become more active threshold levels will be easily breached. Where plants are small and vulnerable growers should be prepared to apply pellets,” he adds.

Pellet choice is an important factor in determining the effectiveness of any control programme and research has shown that the better quality pellets made with high-grade durum wheat flour are more appetising to slugs and therefore more likely to deliver desirable results.

“Effective control is largely determined by the field persistence and palatability scores of a pellet,” says Simon McMunn.

“Wet-process pellets of about 2.5mm persist better than dry-process or mini-type pellets because they are more able to withstand moisture penetration. They are also more easily found and eaten by slugs and spread more evenly due to their uniform individual mass,” he adds.

David Glen agrees that pellet choice is an important factor in achieving adequate control.

“As we learned in 2012, it is vitally important to apply a decent pellet before the crop becomes vulnerable. Baiting points play a part, but pellet quality should not be compromised in favour of more pellets per square metre.”