Supplies of Bontima, the first barley fungicide containing Syngenta‘s widely anticipated carboxamide fungicide isopyrazam, are expected to start arriving on farm this coming week – just in time for the T1 application.
A co-formulation of isopyrazam and cyprodinil, Bontima could add up to an extra 0.5t/ha in yield and raising grain quality, the firm says.
All the key barley diseases are controlled – most to new standards – although the fungicide is predominantly protectant in its activity, says Dave Ranner, Syngenta’s technical support manager.
“It’s a very powerful, long lasting fungicide,” he says. “It doesn’t contain a triazole or a strobilurin, so it will be extremely helpful where sensitivity shifts are starting to affect performance.”
Approved for use in spring and winter barley, Bontima has been developed as an all-in-one solution for use at both T1 and T2. A maximum of two applications can be made, up to and including GS51.
For resistance management purposes, Syngenta is recommending the addition of 1.0 litres/ha of Bravo (chlorothalonil) where the crop is under high ramularia pressure. “Cyprodinil doesn’t offer any help where ramularia is concerned, so this is a sensible precaution,” advises Mr Ranner.
In addition, for curative control of established mildew, a mildewicide should be included, he adds.
“Curative activity of rhynchosporium with Bontima is dose dependent,” he says. “So we recommend using higher rates where you’re looking for more than protection.”
For winter barley, this means raising the rate from 1.6 litres/ha to 2.0 litres/ha, while in spring barley the dose will have to rise to 1.6 litres/ha from 1.4 litres/ha.
The fungicide’s strong greening effect also gives a reduction in screenings and better grain specific weight.
The launch might help growers disappointed by the temporary disappearance of Fandango (prothioconazole + fluoxastrobin). Bontima will be on general distribution, but prices, however, are likely to be as much as 15% more than current favourites.
Isopyrazam is a benz-pyrazole fungicide, containing two important binding effects, says Syngenta’s Rod Burke.
“The IZM molecule binds tightly to the pathogen and to the leaf wax,” he reports. “That’s why it is protective in its nature and so long lasting. Seven weeks of disease control has been shown in our trials.”
This binding ability also helps to make it rainfast within one hour of application, he adds.
Further launches of isopyrazam products are planned by Syngenta, with the first wheat products likely to be on the market in 2011. “After that will be fungicides for oilseed rape, vegetables and top fruit.”
That means the dynamics of the fungicides market will change significantly, as the new chemistry makes it mark, believes Mr Burke.
Isopyrazam has been classed by FRAC as medium to high risk for resistance. “That’s lower than the strobilurins, but it still has to be taken seriously. Our advice is to always use it in mixtures and to make a maximum of two applications to any one crop. But there’s no cross-resistance to the strobilurins.”
Syngenta also hopes to launch in the next two years, sedaxane, a new seed treatment fungicide, a stress tolerance chemical known as Invinsa, herbicide bicyclopyrone for corn and sugar cane, and an insecticide based on cyantraniprole.