Published on 28/04/2023
The new label claim was a welcome Christmas present for NZ growers when it was announced late December, and owes much to the ‘fantastic’ job done by Corteva’s regulatory team.
That’s the word from marketing manager Glen Surgenor. He says Sparta insecticide with Jemvelva active has been approved and used for the same costly, invasive pest in Asia Pacific, Australia and the Americas since fall army-worm began to make its presence felt in those markets.
“Without all that experience in securing regulatory approval overseas, and access to all the trial data and studies that the approval process entails, we would not have been in a position to apply for the fall armyworm claim here in NZ when we did.”
Internal discussions around seeking some level of regulatory approval for Sparta on fall armyworm began in July 2022, he says.
“We could see the industry didn’t have a good option registered for it here. There were some organophosphate and synthetic pyrethroid products they could use in maize, but these didn’t offer the same level of control and there is known resistance to some of this chemistry.”
After initially seeking an operating plan, which would have meant managed use, with applications having to be tracked and recorded, AVCM accepted the submission through the usual application process, allowing the claims to move to the label.
Surgenor says Corteva’s regulatory team both here and in Australia worked closely with staff at the Ministry for Primary Industries, Agriculture Compounds and Veterinary Medicines and the Environmental Protection Authority to lodge the application. In addition to this, letters of support from industry groups and companies such as Far, Pioneer and rural resellers helped reinforce the importance of having Sparta available for growers to help protect their crops against FAW during the current season and beyond.
Labelled use rates for fall armyworm in maize are 250-300 ml per ha (broadcast), with 150-250 litres per ha of water. For sweetcorn, the rate is 400 ml per ha (broad-cast), at the same water rate. Thorough spray coverage is essential for control.
“A submission has been made for aerial applications to be allowed and we are hopefully of this being approved before the end of the 22/23 growing season,” Surgenor says.
After moving through Asia, fall armyworm arrived in Australia in February 2020, and in less than a year became established throughout Queensland, the Northern Territory and Western Australia. It’s believed to have arrived in NZ around February 2022, having being carried on storm fronts from Australia.
The Australian Grains Research and Development Council says it is ‘extremely challenging’ to manage with insecticides, because eggs are laid frequently, and feeding larvae are often concealed inside the crop.
Another challenging aspect is FAW’s strong track record of developing insecticide resistance, with many commonly used insecticides no longer providing control of the pest.
“Having other modes of action available for the industry is going to be important if we want to maintain effective fall army control options into the future,” Surgenor says.