A NEW fungicide which is targeted at protecting potato crops from late blight, will be a welcome sight by Scottish growers.

That’s according to Mike Inglis, technical manager at Airdrie-based Albert Bartlett, which supplies over 20% of the UK's fresh and processed potatoes. As reported in Scottish Farmer last month, agrichemical firm, DowDuPont, has gained approval for Zorvec Enicade in time for applications this growing season.

Growers are always keen to see new chemistry delivered as an additional tool in the running battle to keep resistance to blight at bay, particularly with the new strains A2_37 and A2_36 being found in samples from elsewhere in the EU.

So, Zorvec has been hailed a game-changer by DowDuPont due to its ability to increase spray intervals to 10 days against the current industry standard of seven.

Coupled with the chemistry’s capability to be protective, curative and move into new growth suggests the greatest benefit is likely to be gained from targeting use during the crop’s rapid growth stage.

Mr Inglis said he expected growers to experiment with application timings and partner products to fit their specific programme requirements in providing the best possible blight control. As one of many agronomists and growers who have tracked the development of Zorvec over the past 13 years of development, he is keen to see it put to work.

“I have seen Zorvec quite extensively from 2005 in trials run by Dr Ruairidh Bain, at the SRUC,” he said. “The plots in these trials always stood out as bright green compared with other fungicides being trialled which had all been inoculated with blight.

“I also went to see the product being trialled in Holland, last September and the foliage blight control was impressive, in combination with the other partner products.”

The formulation is based on the active ingredient oxathiapiprolin which gained UK approval in January and will be available for inclusion in spray programmes this spring. It will be supplied in an agronomy pack alongside a partner product with an alternative mode of action as part of an anti-resistance strategy.

DowDuPont reckon that using the molecule in a mixture should help ensure 'this revolutionary chemistry is protected for the long term'.

Mr Inglis added: “I think growers in Scotland will play around with the partner products – cymoxanil plus mancozeb or amisulbrom – supplied in the pack to get the best from Zorvec in their programme. The season will clearly have a say in how it is used in 2018.

“But it is particularly welcome for the north of the UK where fewer weather windows in wet seasons can make blight control difficult. Its 10-day persistence will be something new for growers to think about and whether they use the full interval will probably depend on the blight pressure in any particular season.

“I certainly know of some Scottish growers who are intending to use it at seven-day intervals first until confidence in their preferred agronomy pack has been explored. From studies to date there doesn't appear to be any residue issues or resistance to new blight strains with oxathiapiprolin, which is a further benefit when compared with some of the main blight chemicals currently on the market.”

DowDuPont’s Craig Chisholm added that flexibility will be a key attribute: “Longer spray intervals will be something new for growers to consider, but we feel they will immediately see the benefit of added flexibility, plus the opportunity to drop one spray pass when this 10-day strength is utilised in a block of two,” he said.

“By ensuring no infection is sporulating under your crop canopy – achieved by two applications in the rapid growth phase of the crop – blight pressure over the rest of the programme will be greatly reduced and growers still have one or two Zorvec sprays in reserve across the remainder of their programme.”

Growers have lacked a truly systemic blight fungicide since phenylamides came under pressure from resistance in some parts of the UK and while Mr Inglis uses varieties that are robust against blight, he acknowledged the need for a product with the ability to control all known resistant strains.

“We’re not really seeing resistance issues in our Scottish acreage at the moment, which I think is down to the varieties we use which are fairly resistant to tuber blight,” he said. “But there are very few systemic products on the market that can control all blight so there is no doubt that anything with that capability is welcome.”