Nufarm's fungicide Opera was praised after the trail

Opera was released by Nufarm earlier this year to tackle diseases such as stripe, leaf and stem rust in wheat, and both forms of net blotch in barley.

The fungicide has two ingredients, one used for the first time in countering cereal diseases.

Nufarms Alex Ford told Southern Farming Systems recent AgriFocus field day at Lake Bolac the two ingredients were epoxiconazole - the key component of Opus fungicide - and pyraclostrobin, a strobiluron fungicide only used in Australias horticultural industry in recent years.

Mr Ford said fungal diseases attacked plants when a spore landed on its leaves.

"The spore germinates and puts out tubes which penetrate and infect the plant," he said.

"Epoxiconazole worked best once the infection has started on plants. So it gives you some forward protection and some curative, and the pyraclostrobin is very, very strong as a protectant.

"It stops the spores from germinating and stops the initial tube coming out of the spore."

Pyraclostrobin also kept the plant green longer.

"That gives the plant more time to photosynthesise, grow and put on yield," Mr Ford said.

Opera was developed by BASF to protect wheat, barley, oats and oaten hay crops.

It can be used against powdery mildew, leaf rust and both forms of net blotch in barley.

In wheat, it controls powdery mildew and septoria, as well as the three rust diseases.

Nufarm recommends farmers spray their crops when they reach growth stage 32, followed by another application at growth-stage 39 to protect the flag leaf.

"We have had very good feedback from those who have tried it," Mr Ford said.

Nufarm said the cost of application was about $25-$30/ha.