Potato growers have been quick to incorporate a new novel insecticide for controlling aphids and Tomato-Potato Psyllid (TPP) in their crops this past season.

“A lot of growers were aware of it before we launched because of its use overseas, and we expected there would be quite a lot of demand for it as soon as it became available in New Zealand,” says Nufarm Technical Advisor Andy Davis. “Even so, it’s taken off.”

The insecticide in question is Mainman, a systemic insecticide which contains the active ingredient flonicamid, discovered and developed by Ishihara Sangyo Kaisha (ISK) of Japan.

It’s a brand-new molecule, with a unique mode of action, and it has an excellent fit with Integrated Pest Management (IPM) programmes. Mainman’s mode of action is different from other insecticides such as neonicitinoids, and it is the only insecticide in the IRAC Group 29 class.

Andy says an important attribute is its ability to stop aphids and TPP feeding within an hour, working through both contact and ingestion.

“Mortality occurs within two to five days, but the fact that they’re not feeding so soon after application really helps limit crop damage and disease transmission.”

Formulated as a Water Dispersible Granule (WDG), Mainman is rainfast within three to four hours, and has residual activity for two to three weeks. Translaminar and systemic movement within the plant allow the active ingredient to reach new growth as well as the underside of leaves, which is essential for controlling both TPP and aphids.

“Critically, Mainman has no reported cross-resistance with other insecticides and poses a low hazard to beneficial insects, so as well as offering a valuable new rotation option for insecticide resistance management, it is also ideal for IPM programmes.”

Field trials¹ with Mainman in New Zealand have shown exceptional control of aphids and good control of TPP, comparable to current commercial standards.

Both aphids and TPP pose potentially costly losses to local potato growers, Andy says.

Several species of aphid are vectors of Potato Leaf Roll Virus (PLRV) and other viral diseases. PLRV-infected plants are stunted and have upward rolling of the leaves. Diseased plants produce fewer and smaller tubers.

TPP cause stunting and yellowing of potato foliage and transmits a bacterium which causes a tuber disease known as zebra chip. Plants infested with TPP produce small tubers and are unsuitable for processing as they exhibit dark stripes when fried.

“TPP has had a devastating effect on commercial crop growers since it was first detected here in 2006,” Andy says. “The more control options they have at their disposal to help manage this pest, the better.”

He’s heartened by how quickly the industry has taken advantage of this new technology, and says it reinforces the value of registering ‘niche’ or small-market chemistry for New Zealand producers.

“Feedback has been excellent. It’s certainly found its place in the potato market. It’s a useful product for protecting the marketable value of crops, and growers have been quick to pick up on it.”

Mammalian toxicity is low, and the new product is registered for both ground and aerial application. The recommended application rate is the same for both pests (160 g/ha), with no more than two applications per crop, and withholding period of seven days.

For more advice on using Mainman to protect crop yields and productivity, talk to your local Fruitfed Supplies Technical Horticultural Representative.

ACVM registration number: Mainman® #P008742. Read registered label before use.

1 2021 trial NUNZ2135, Hawke’s Bay (aphid); 2020 trial NUNZ2070 Hawke’s Bay (psyllid).