Published on 01/07/2020
Even so, Corteva Agriscience’s research and development manager is pretty excited about the company’s latest launch.“Questar™ fungicide, for Septoria control in wheat, is world-class. It’s definitely an All Black in terms of performance and attributes – so it’s been a dream to research.
”NZ farmers will be the first to buy the novel fungicide this season, because it has yet to be launched in other countries. But Harris has been working with it in field trials in Canterbury since the 2017/18 season, and conducted his first scoping trials with it eight to ten years ago.
So, what’s got him so enthused about this new fungicide?
First up, Questar features a new mode ofaction (MOA), with no resistance or cross resistance to existing MOA’s, meaning it will control Septoria strains that are resistant to other MOAs. “It has top shelf performance against Septoria; provides a flexible application window and has a very favourable mammalian and environmental profile."
Questar will also be the first naturally derived fungicide brought to market by Corteva Agriscience, as its unique active ingredient, Inatreq™, is produced by fermentation of a naturally occurring soil bacterium first discovered at Osaka University in Japan. Inatreq active is the first member of a new class of cereal fungicides, the picolinamides (Group 21), which have a different target site to all other fungicides currently applied for Septoria control in wheat. As such, Questar is a significant advance in fungicide resistance management in wheat, as well as providing excellent Septoria and rust control when tank mixedwith an appropriate partner.
Canterbury farmers who have helped Harris trial the new fungicide over the past three seasons have been ‘universally enthusiastic’ about the development and commercialisation of such an important new class of crop protection fungicides. “They like the fact that Questar has a new MOA, with no cross resistance to existing fungicides in the wheat market, and is highly efficacious."
Another important benefit is the flexibility in application timing – up to T3 – although most applications will be at T1 or T2 which are the most important fungicide timings for Septoria control. “We’re strongly recommending only one Questar application per season, which will help protect Questar from the development of resistance, and also make the most of this new MOA in slowing resistance to other fungicide groups,” Harris explains. “We very much want to be part of a responsible resistance management strategy for all fungicides for Septoria and other cereal disease control."
Corteva Agriscience marketing manager Glen Surgenor says the launch of Questar will allow growers to reduce their reliance on SDHI fungicides within their wheat spray programmes. “SDHIs are still going to be very important. We look upon them as critical resistance management partners, because without them we could see loss of efficacy of both Questar and the SDHIs, as well as other modes of action. What Questar does is widen the options for disease control in wheat."
Without the support of PGG Wrightson Agritrade as a partner on this project, it’s unlikely Questar would have come to NZ,certainly not as quickly as it has, Surgenor says. Field testing in NZ has been complex and thorough, and nature has helped by providing three seasons of differing disease pressure, from high to moderate.
As well as the untreated control plots, trials with Questar compared disease control from standard competitor fungicides, and a range of different application rates and tank mix partners. The 14 Questar field trials conducted in NZ benefited from dozens more trials completed overseas. In total there have been at least 100 field trials with Questar conducted world-wide over several seasons. Further research will occur in 2020/21. Bernard Harris is already planning his research programme for the coming season, extending field trials to the North Island– either Manawatu or Hawke’s Bay – and Southland, as well as more work in Central and South Canterbury.
Questar is registered in NZ for both conventional ground and aerial application,and will be available this spring in a 7.5 litre pack.
For more information, contact your Corteva Agriscience territory sales manager.