Superior seed-bed can ward off slugs
Slugs can be beaten, but every weapon in the book will be needed if you hope to
win the war, says an East Anglian agronomist. Andrew Blake reports
EVEN with current technology growers will never completely protect crops from the ravages of slugs, admits a Cambs-based distributor agronomist. But adequate control is perfectly possible, provided growers have a sound battle strategy planned.
"Farms which take every opportunity to keep background slug populations low by starving them, using chemical control and paying attention to seed-bed quality, are by and large getting good crop establishment," says Dick Neale of Hutchinson.
Growers who regularly get establishment problems tend to pay less attention to cultivations and allow stale seed-beds to green up before drilling, he says.
"Power harrows which produce pebble-like seed-beds have a lot to answer for. Slugs can easily move between the clods to find sown seed. Seed-bed quality is over-riding in preventing grain hollowing."
Several factors have gone against growers in recent seasons, he says. Those include the move to rapid crop turn round in the autumn using more powerful tractors and powered soil moving implements. "People are having to beat soils into submission rather than use weathering. Soils are often worked while they are still too plastic and this leads to the pebble effect. The straw burning ban also saw slug populations increase rapidly."
Slugs love the meals served up by early worked seed-beds after oilseed rape and peas which are left to green, warns Mr Neale. "Cultivated fields should be sprayed off as soon as volunteers reach one-leaf. Pellets can then be applied pre-crop so the slugs have nothing to go at except the pellets."
Failure to consolidate properly after each cultivation is asking for trouble. It allows slugs to move easily through the upper soil profile and looses moisture. "Dry, cloddy soils offer poor seed/soil contact, produce poor or uneven germination and give slugs time to hollow out the seed," he explains. "Todays in-vogue presses and land packers do help."
Main slug pellet options
Product Active ingredient Max indiv Pellets/sq m Cost £/ha
Draza/Exit Methiocarb (4%) 5.5 38 25.00
Genesis Thiodicarb (4%) 5 32 22.50
Optimol Metaldehyde (4%) 15 94 26.50
Metarex Metaldehyde (6%) 8 33 22.50
ESP Metaldehyde (6%) 8 52 21.50