The fungicide arrived on the market at the beginning of this year (2009) to treat all four spotting diseases and powdery mildew on cabbages and leeks. The Allium and Brassica Centre's Andy Richardson said: "Rudis' label extension is good news for growers as sprouts are the most difficult Brassica crop to control fungal diseases in and the armoury has become limited in recent years.

"Our trials have shown Rudis to combine strong protectant and eradicant activity against all four major leaf spot diseases of sprouts as well as powdery mildew."

As for leeks and cabbages, the maximum individual dose permitted on sprouts is 0.4l/ha. It is approved for three applications per crop. The latest time for application is 21 days before harvest.

The product is a new development of the firm's triazolinthione (tzt) technology, formulated specifically for vegetable crops with the active ingredient prothioconazole.

Nathan Whitehouse, Bayer's product manager for fruit and vegetable crops, said the tzt technology in Rudis is distinctly different to that of the demethylation inhibitor (DMI) products growers rely on.

"Rudis adds a third dimension to disease control. Being a new generation DMI it's unique in delivering greening and physiological yield effects in the same league as strobilurins. Its tzt technology brings much-needed freedom to access these benefits while keeping programmes within fungicide resistance management guidelines."

- The new Rudis product label can be downloaded from www.bayercropscience.co.uk

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