A BUZZ word at many field days this year has been fungicide seed treatment Systiva, popular because of its suppression of common barley diseases during the early stages of crop development.
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The results have been so impressive that the seed treatment was used across all SA barley national variety trials sown in 2015.
At the Wunkar and Loxton Ag Bureau crop walk in October, SARDI New Variety Agronomy program leader Rob Wheeler said Systiva seemed to be "a good product for a wide range of disease control".
"The GRDC, who fund the trials, were wanting to know the real yield potential of varieties without the influence of various diseases," he said.
"And Systiva trials showed good suppression of all the major barley diseases, such as net blotch, leaf rust, scald, smut and powdery mildew.”
SARDI plant pathologist Hugh Wallwork said comparison trials conducted on the Eyre Peninsula showed Systiva had particularly “good performance on spot form net blotch".
"We didn't really have an effective seed treatment for net blotches before," he said.
"SARDI Field Crop Evaluation used it on trial plots in 2014 and we observed that it was very effective in control right up to flag-leaf stage so it was used across all NVT yield trials this year."
Systiva is among new broad-spectrum fungicides from the succinate dehydrogenase inhibitor (SDHI) class (group 7). It features the active constituent fluxapyroxad, which prevents disease development by stopping energy production in the fungal pathogen.
The seed treatment was developed by the world's biggest chemical company BASF "for the control of a range of seed and foliar fungal diseases of cereals and the suppression of rhizoctonia root rot". In Australia however, it is mainly marketed for barley diseases, particularly net blotches.
The company boasts that the seed treatment will eliminate the need for early fungicide applications, but also recommends that Systiva be followed by a late foliar fungicide as part of a program.
Dr Wallwork, who is currently producing a seed treatment fact sheet, agreed.
"SDHI fungicides are prone to loss of efficacy when used repeatedly against some pathogens," he said.
"Already some net form isolates have been detected in northern Europe that show increased resistance to these compounds.
"It is important therefore that fungicides are used as part of a package of control measures that includes useful variety resistance and alternatively active ingredients such as the triazoles."
