Blight switch flicked
Blight pressure risk has gone from green light low, to a wall of red across most of the UK this week, according the Syngenta BlightCast results.
Having seen the risk approaching most growers and agronomists would have, rightly, reached for the OXTP, advises Syngenta Technical Mananger, Michael Tait.
Now, the challenge is to prevent any development of initial blight infections that may have got into the crop. Along with the inevitable further pressure from untreated crops, dumps and groundkeepers that will be high risk sources of inoculum.
"Following FRAC guidelines, to protect remaining chemistry from resistance, a move to Revus for the protection programme through the stable canopy phase of the season would look a good solution," he advocated.
Research has shown that Revus is effective against all blight isolates, including the more aggressive EU36_A2. It is also the most effective straight CAA fungicide group active available, which gives growers and agronomists the chance to mix appropriate partners to counter specific seasonal challenges.
Using a mix partner with Revus enables the use of up to six CAA fungicide group applications in a full fungicide programme, within FRAC guidelines.
"As one of the key remaining fungicide groups, and with further mix options under threat, Syngenta Potato Science research will be evaluating Revus tank-mix options in trials this season," reported Michael.
Look out for Syngenta Potato Science Live meetings to find out the results, or talk to your Syngenta Area Manager
Localised and intense summer rainfall events reinforce the value of Revus rainfastness. Trials and growers’ experience has repeatedly shown that, with the active rapidly locked into the leaf wax layer within an hour of application, effective protection remains even after heavy rainfall or irrigation.
"The better news for growers, is that Syngenta weather spray window forecasts indicate opportunities for fungicide applications over the coming days," he added.
The main challenge will be finding slots between moderate to strong winds, particularly in northern areas.
This season, following promising results last year, further research at the Eurofins blight evaluation trials, in Derbyshire, will assess application with new 90% drift reduction nozzle designs. It will also look at the potential for optimising performance using drift retardant with Revus.
Watch out on the Syngenta website or follow @SyngentaCropsUK on Twitter for in-season updates of blight trial progress and results
BlightCast 2020 vision
Syngenta BlightCast is now live and running for the 2020 season, to give growers and agronomists an unrivalled picture of impending blight pressure and risks – in time to make active application decisions.