Wine and table grape growers have brand new chemistry available for the costly diseases botrytis and powdery mildew, with Corteva Agriscience’s flexible, highly effective fungicide, Verpixo Adavelt active, entering the market and the Australian Wine Research Institute’s updated Dog Book.
Key to the success of Verpixo Adavelt active is its unique status as a Group 21 mode of action fungicide with no cross-resistance, making it a welcome resistance management tool.
Based on a naturally occurring compound found in soil bacteria, the fungicide has been trialled extensively on vine, fruit and vegetable crops in four states and in August, gained approval from the APVMA for new crop registrations to deliver broad-spectrum control of ascomycete diseases.
The new mode of action is keenly sought in viticulture, particularly in vineyards in high rainfall zones susceptible to botrytis and powdery mildew.
These include McLaren Vale, Coonawarra and the Adelaide Hills in South Australia, the Yarra and King Valleys of Victoria, Tasmania, the Hunter Valley in NSW and southern WA.
Corteva Agriscience customer technology specialist, Chris Brown, said Verpixo provided growers with a strong preventative alternative to products they had been using for many years.
“Verpixo is biologically inspired, broad spectrum, safe to crops, safe to users, has a short pre-harvest interval of one day for most crops, a rainfast period of three hours and tank mixes are possible,” Mr Brown said.
“The most important factor is flexibility of timing for the application of Verpixo to control botrytis.
“The Australian Wine Research Institute (AWRI) approved two applications up to E-L 31, berries pea size, and this is a major bonus for vignerons as a lot of alternate control chemistries are limited to E-L 25 and E-L 29.
“Timing is critical to protect grapes from botrytis in potential infection sites at inflorescence, so the E-L 31 positioning for Verpixo is important – it’s the final chance to put covers on the berries before the bunch closes, and it will give wineries everywhere a lot more flexibility in their spray program.”
Verpixo has no export harvest interval when applied up to E-L31, making it well suited to short season varieties such as pinot and chardonnay and giving it a significant advantage over alternative products that can be applied up to E-L 29, but have an export interval and a withholding period of 60 days before picking.
Analysis by the AWRI’s Affinity Labs show no faults or taints in wine following Verpixo treatment of grapes and concluded the fungicide had no detrimental effect on wine making or taste.
“Verpixo has an enviable safety profile – there is no re-entry period required so a grower could spray now and go back into the vineyard in an hour,” he said.
“Growers seeking to control botrytis with Verpixo will achieve control of powdery mildew at the same time, without having to worry about adding another product or compatibility.
“It’s a great alternative, especially as a new mode of action for resistance management. Verpixo has been registered for control of botrytis and powdery mildew in strawberries for the past 12 months and achieved spectacular results.”
In a bonus for integrated pest management (IPM) programs, Verpixo was rated as ‘harmless’ to key beneficials commonly found in the vineyard, even at double the recommended rate.
Verpixo should be applied as a preventative at a rate of 150ml/100L prior to infection when conditions are favourable to disease occurring, and with a suitable adjuvant.
While copper fungicides are physically compatible in tank mixes with Verpixo, it is not recommended, as copper reduced the level of ’powdery mildew’ control in some trials.
Corteva Agriscience recommends growers producing domestic wine and table grapes apply a maximum of two treatments of Verpixo per season and forgo harvest for 10 days after application.
Export growers are advised to consult their exporter for advice prior to using Verpixo Adavelt active.
