Published on 27/09/2022
But when it comes to one of the most common pests that affects spring sown crops and pasture, it’s always better to be proactive rather than reactive, especially in direct drilling situations.
While there are many species of introduced slugs in this country, the grey and brown field slugs cause the most damage to crops and some pasture.
No matter how well your farmers have prepared paddocks for spring sowing – or even what they intend to grow – these small creatures can still eat a big hole in their new seedlings before they know it.
Capable of taking out 20-50 per cent of new plantings in no time (sometimes even more), slugs love clover. But they will also consume cereals, maize, forage brassicas, fodder beet and grass, attacking and hollowing out newly sown seed, destroying the plant embryo and eating new shoots before or after emergence.
Once a problem does become apparent, a lot of damage may have already been done that cannot be reversed, says Nufarm technical specialist Paul Addison.
“The price for getting it wrong is just too high, especially when you’re looking at the overall investment required for sowing a paddock of new grass or crop.”
Addison says there are several types of bait available. However, if farmers want to protect beneficial predatory beetles – which help control slugs in the paddock – baits containing methiocarb should not be used, because they cause secondary poisoning.
Metaldehyde, the active ingredient in SlugOut All-Weather Slug and Snail Bait, is not harmful to earthworms, either; poisoned slugs pose no threat to birds or small mammals.
Another key consideration in picking the right slug control is coverage, or the number of bait points per square metre, Addison advises.
“Industry research has repeatedly reinforced the importance of coverage in obtaining effective control where high numbers of slugs are present, most recently in the Foundation for Arable Research’s latest Integrated Pest Management guide. This is where SlugOut comes into its own,” he says.
“At the recommended label rate of 10 kg per ha, FAR trials show SlugOut has 112 bait points per sq metre, which is much higher than other baits with the same active ingredient.”
He strongly encourages checking paddocks before sowing, leaving out sacks or boards for two or three nights to find out if slugs are present.
Bait should be automatically used in all no-till situations, because not cultivating creates ideal conditions for survival. If cultivated seed beds are cloddy, farmers should monitor and consider baiting.
SlugOut All-Weather was a world first when it was jointly developed by Nufarm and AgResearch more than 30 years ago.
Addison, who was part of the development team, says the metaldehyde-based product combines excellent weatherability, mould resistance, palatability and efficacy.
The unique formulation of SlugOut concentrates the metaldehyde in the outer part of the bait ensuring a lethal dose is rapidly ingested by slugs.
Before it was developed, the only choice was extruded cereal bait that fell to bits in the rain
“What we designed is a bait that doesn’t break up when it rains and has an edible coat on the outside of an inert core.”
For more detail contact your local Nufarm territory manager or visit nufarm.co.nz