Slugs – the ‘sniffer dogs’ of the mollusc world

Slugs have hidden talents that make them a nightmare for crop establishment. Pieter Van Der Westhuizen, UPL NZ Ltd Regional Manager Upper North Island, says getting ahead of them is key.

BioGro certified Ironmax Pro – the ultimate lure

“Slugs have an acute sense of smell and are aware of seedlings even as plants are just breaking the surface. By the time slugs are feeding on emerging seedlings, it’s already too late as seedlings damaged by slugs usually won’t recover.

“The goal is to protect the crop. Once feeding damage has stopped, that’s been achieved. We don’t have to see dead slugs to know we were successful.”

Colzactive technology

Ironmax Pro uses slugs’ multiple olfactory sensors against them. The breakthrough Colzactive technology makes it their favourite food.

Colzactive is made from specially selected oil seed rape extracts. Twenty plant species were evaluated and 50 potential molecules identified for their attractiveness to slugs. Two molecules from oil seed rape were chosen for their highly palatable characteristics. These form the basis of Colzactive, enhancing the Ironmax Pro bait taste and speeding up how quickly the baits work.

Cage trials in 2020 showed slugs preferred feeding on Ironmax Pro to feeding on plant seedlings.

Contractor feedback

Contractors report strong performance and easy flow through machines.

“They’ve said it performs well and flows through machines—no problem at all.

“Contractors are also finding the product is a good ecological match for the increasing number of clients who prefer not to use products that impact the environment.

“Pet and stock safety is important. Stock break-outs and gates left open are part of farming life, no matter how careful you are. Similarly, the family labrador or huntaway needs to be safe when it’s stretching its legs or working on the farm. With Ironmax Pro, there’s no problem. It’s also safer for beneficial insects. And while the slugs will sniff the product out, it’s definitely more pleasant in terms of odour for those working with it—especially in confined spaces.”

Performance and application

Ironmax Pro contains the optimised active ingredient 24.2 g/kg ferric phosphate anhydrous (IPMax). Ferric phosphate is a natural soil component. In Ironmax Pro it acts as a stomach poison on slugs and is fatal once ingested. Feeding stops almost immediately.

Baits are made with the finest durum wheat using a unique slow-drying process, making them highly rain-fast (up to 60 mm of rain) unlike some baits that dissolve in wet conditions.

Ironmax Pro also has consistent, wide spreadability with a recommended application rate of 5–7 kg/ha. With 60,000 baits per kilogram, the product has excellent ballistic properties.

“The uniform pellet size and innovative Ironmax Pro manufacturing process mean bait can be spread at widths of up to 24m.”