Collaboration delivers smarter approach to late blight control

Sometimes, doing the right thing is neither the easiest, quickest nor most financially profitable course of action.

But when it comes to fungicide stewardship, safeguarding a relatively new mode of action, and making it simpler for distributors and end users to do the same, outweighs shorter-term priorities.

Which is why Corteva Agriscience has released an innovative fungicide co-pack for potato growers, featuring both its own product and that of a competitor.

Zorvec Enicade (Group 49), a foundational fungicide for control of late blight in potatoes, is now available packaged with Ranman 400SC (Group 21), from UPL.

Corteva Technical Specialist John van der Linden agrees sourcing a co-pack partner from a competitor is not a common step, but it is an innovative approach to addressing effective stewardship of both products.

And it aligns perfectly with Corteva’s global strategy to enhance resistance management for Zorvec Enicade.

“We’re trying to protect the long-term efficacy of this product by making sure it is sold and applied with a different mode of action (MOA) at the same time.

“Awareness of resistance is increasing among farmers and growers, but we as suppliers need to be proactive as well, and protect our products in the market so they don’t develop resistance.”

Finding the right co-pack product took time and patience. It had to be available in New Zealand, registered for the same use and effective on its own as well as in combination with Zorvec.

The active ingredients within each product are at risk of developing fungicide resistance if continuously applied alone, but combining them prolongs the use of both for managing potato late blight.

Local trials to support ACVM approval of using the tank mix in potatoes began in 2021, and have consistently shown excellent control of late blight when applied preventatively.

“Zorvec Enicade + Ranman co-pack fungicides are highly effective as they have multiple effects on the late blight pathogen’s life cycle, providing unmatched consistency and control for a healthier crop.”

They have preventative, locally-systemic and translaminar activity to protect new plant growth as it emerges and grows for better crop establishment.

They also move quickly into the waxy epicuticular layer of plant tissue, making them extremely resistant to wash-off after just 1 hour after application.

“There is no cross-resistance with existing fungicides,” van der Linden adds.

Historically associated with Irish potato famine, late blight is one of New Zealand’s most economically damaging potato diseases, and can cause total crop loss.

The potato market is not a big one, says Marketing Manager Nicole Morris.

“But that was not our motivation for doing this. We launched a new product, and we wanted to make sure it would be here for many years to come in that industry.”

The co-pack is sold by Corteva, and each one contains a five litre container of Zorvec Enicade, and a five litre container of Ranman.

Labelled application rates for control of potato late blight are 120 m/ha of Zorvec Enicade with 200 ml/ha of Ranman.