Potato growers are being urged to stay on top of blight disease this season as late spring plantings mean it is even more critical to maintain green leaf area through the summer to maximise yields.

In such a late planting season, crop experts say robust blight control will be vital after delayed crop establishment is likely to lead to late harvests and potentially lower yields.

Andy Alexander, independent agronomist, says this season is the most variable he has witnessed in his career and so assessing disease risk and timing blight sprays will be crucial.

“The key for every grower is to tackle blight and the main strategy must be to run a really robust protection programme. Growers need to use all the chemistry in the toolbox in the correct place at the right interval,” he says.

See also: 3 fungicide strategies to fight resistant potato blight

New fungicide chemistry this season comes from oxathiapiprolin, which is a new active ingredient and mode of action, and is marketed as Zorvec Enicade by Corteva Agriscience, the agriculture division of DowDuPont.

“This new chemistry will be a welcome addition for growers who must consider all the chemistry at their disposal. As with any new product we will see growers and agronomists working out the most effective way to deploy it as part of a robust blight programme,” adds Mr Alexander.

© Tim Scrivener

Robust programmes

Craig Chisholm of Corteva says growers and agronomists will need to know their varieties and make timely decisions on robust spray programmes this season.

“Crops will grow fast now and it is quite possible the blight risk will be higher due to soft growth and lack of attention to discard piles in the scramble to get the crop in the ground,” he says.

Mr Chisholm adds growers need to maximise their existing yield potential given the light interception already lost.

Growers are going to need every bit of green leaf area they can get and that means they need the cleanest possible start to the blight programme, he says.

He points out some growers have made their first applications of the new fungicide in the past week and he adds the product’s strong preventative and curative activity along with proven stem blight activity and movement into new growth will be useful especially in the rapid growth phase of the crop.