Slug risk to late-planted spuds
SLUGS look set to hit potatoes harder than usual this season. But controlling them with pellets can be tricky, warn specialists.
Late plantings after the wet winter, especially of susceptible varieties like Maris Piper, are particularly prone to damage, says ADASs Jon Oakley. "Slug control will be more important if lifting is delayed to allow late-planted crops to bulk up."
"The longer crops are in the ground the more the risk of damage," adds SACs Andy Evans.
"After the wet winter some will have been hammered as soon as they went in, so it doesnt bode well."
Many growers apply pellets as protection. "There is always a fair chunk of the crop that gets treated," says Mr Oakley. "If you have Piper and expect to lift late you probably need at least one application." Treatment after irrigation or heavy rain, when the pests are more active on the soil surface, should give best results.
Trapping can help identify potential slug problems, but is less useful than in cereals. "It cant tell you whether you will get damage," says Mr Oakley.
Although the keeled slug is the worst culprit, other species, such as the yellow-soled slug, have different life cycles which may merit different treatment timings, he adds.
"Control can be a bit of a lottery," admits Dr Evans. "If you get 50% you are not doing too badly. Its all very dependent on the conditions. But you can up the odds by trying to target the pellets to the base of the plants."
The main aim should be to apply a long-lasting formulation, such as Bayers new methiocarb wetex, before crops meet in the rows. "You may still need to go later if test digs suggest it."
But the distribution of pellets applied after full ground cover is much more hit and miss, he adds. *
• Big threat to late plantings.
• Higher risk as lifting delayed.
• Pellets most effective after wet.
• Target to base of plants.