The surprisingly rapid spread of resistant Ramularia in New Zealand, and in the UK and Europe, had the industry looking for solutions.
 

Claire Mills, Adama NZ’s technical services and development manager, says approvals for multi-site protectant Phoenix and for DMI fungicide Bolide have been good news for growers.
 

Mills says the registration is the result of hard work, here and in the UK, and internal trials, backed by FAR trials.
 

T2 is the optimum timing for a multi-site like Phoenix, which means next season is going to be where it makes the real difference for most barley growers.
 

Both Mills and Daren Mabey, Adama NZ commercial manager, emphasize that the aim of resistance management is to slow down selection for fungicide-resistant strains in the population and to protect existing chemistry.
 

Mabey says some growers are still having good results with SDHIs as other factors, including the choice of cultivars, other diseases present, and weather can play a part in how well a crop comes through.
 

He says the success of Phoenix in the FAR trials, in particular, has surprised some people.

The FAR trials found that adding multi-site protectant fungicide Phoenix to Proline or mixes of triazole with SDHI in a two spray programme gave significantly better control of Ramularia than the standards alone, and also increased yield (FAR Crop Action edition 134, 14 September 2018).
 

Further trials are planned for 2018/19.

Daren Mabey says it is hard to generalise, but the issue of Ramularia resistance has been building up in NZ for several seasons, and has reached ‘quite high levels’.
 

“At the end of the day, resistance is not going away and people will see benefits from Phoenix. There’s enough data to show it’s highly effective in tank-mixtures.”
 

Phoenix (phthalimide – Group M4), which contains the active ingredient folpet, works against Ramularia at multiple sites, making it a low risk for resistance development.
 

Currently there is no known resistance to folpet anywhere in the world.
 

Phoenix is now the only currently approved class of chemistry in barley that does not exhibit Ramularia resistance and can protect DMI chemistry from resistance development – essential as DMIs continue to provide a high level of control including curative activity.
 

For more detail contact Adama or visit www.adama.com.