Perfect conditions for the worst of the slugs
Conditions for slug activity and breeding throughout the south of Australia have been ideal, thanks to good rainfall since last spring. One of the most threatening species is the black-keeled slug.
Prepare now to protect vulnerable crops such as germinating canola, pulses and pastures.
What we know about the black-keeled slug
The black-keeled slug is recognisable by its uniform, dark colour and the prominent keel just behind the top of its head.
We know from previous research, particularly on grey field slugs, that these field slugs will start moving in the soil profile with a moisture capacity of 20 per cent and begin breeding with when the capacity reaches 25pc.
Unlike other species, black-keeled slugs are a burrowing species that can attack germinating seeds in the drill row prior to emergence, wreaking more serious crop damage than other slugs.
Where to look
You should not only be baiting for slugs in very vulnerable areas – within paddocks and on farms – but monitoring in general.
It’s really important to monitor each paddock in a vulnerable area, where high stubble and trash cover in a paddock or where minimal cultivation has occurred for many seasons. Paddocks with a high water-holding capacity tend to attract slugs more than paddocks with a lower water-holding capacity.
Deploy 20 to 30 tiles or bags that hold the moisture and check underneath them regularly. Agnova has a silver-filmed mat designed specifically for slug monitoring, which holds water and is very useful.
The best time to check for slugs are during the night and early mornings or whenever conditions are damp and mild.
Check the application rate for each bait because they do differ. Some baits have an application rate of 5 kilograms a hectare to achieve 30 to 50 baits per square metre, whereas some other baits have a minimum application requirement of 10kg/ha to achieve 30 to 50 baits/m2. It’s very important that the distribution of the baits is even, as a slug will not die without encountering bait.
Metarex Inov is a premium bait with a low application rate. It has a high rainfast period so doesn’t dissolve easily, extremely even spreadability and, most importantly, it has a unique attractant in the bait formulation to attract the slugs.
Article written by Elders Albury agronomist Chris ‘Desi’ Toohey.
Elders offers a range of crop protection products. View the range.
Contact your local Elders agronomist for assistance with with controlling slugs before they damage your crops.