Breakthrough fungicide arrives for barley growers

A BREAKTHROUGH fungicide has arrived in time for barley growers looking for better disease control, yields, quality and green leaf area.

Bontima from Syngenta is being launched just when winter and spring barley could benefit from a boost against the effects of low grain prices. It is the first treatment containing IZM (isopyrazam) – a new, broad-spectrum fungicide from a new ‘benz-pyrazole’ chemical group.

The spray represents an important introduction for barley, claims Syngenta cereal fungicide manager, Rod Burke. Working in an advanced way to shut down disease, it brings together two powerful ingredients to combat all major barley disease threats.

Trials show that Bontima gives outstanding protection against rhynchosporium, net blotch, ramularia, barley leaf spotting, brown rust and powdery mildew, said Mr Burke.

“It delivers greener and cleaner crops resulting in repeatedly higher yields and quality. Yield increases of up to 1 t/ha have been seen over a current leading fungicide standard in trials.”

Bontima does not contain commonly-used triazole or strobilurin chemistry. This is important, says Mr Burke, because there have been concerns about shifts in sensitivity in net blotch to strobilurin chemistry – and in rhynchosporium and net blotch to triazoles.

“These issues, together with the need for higher barley yields to help counter grain price pressures, plus increasing problems of ramularia and abiotic spotting, have all created a clear need for innovation in barley disease control.”

In particular, the breakthrough with IZM comes from the advanced ‘double binding’ properties of its ‘benz-pyrazole’ structure which binds strongly to the fungus.

This makes it highly potent against disease and leaf waxes to provide long-lasting protection, says Mr Burke. “In this way, IZM is able to provide a durable barrier in the leaf wax, controlling disease before it is even able to penetrate the plant.”

As well as giving reliable control of triazole less sensitive and strobilurin-resistant strains of net blotch, Bontima has also reduced the level of rhynchosporium infection in trial plots from over 30% to zero percent.

Similarly, ramularia infection has been reduced from around 98% to just 2 or 3% with Bontima treatment, while untreated green leaf area of 40% in trial plots was doubled following Bontima use to 80%.

In terms of yield, a programme of Bontima at 1.6 l/ha boosted output by more than 2.4 t/ha over untreated and by as much as 1.1 t/ha over strobilurin + triazole use.