UK: Drift reduction keeps blight sprays on target

Syngenta New Farming Technologies lead, Harry Fordham, highlights that UK regulatory authorities have been positively encouraging the adoption of drift reduction techniques, which will likely be a further focus of their attention in the future, he believes.

The company’s application research has pioneered the development of 90% drift reduction nozzles for use across a wide range of crops and treatment timings over recent seasons, including potato applications from pre-emergence herbicides, through to full-season blight foliar treatments and desiccation.

“New designs of angled 90% drift reduction nozzles offer the potential to improve spray penetration throughout the crop canopy with larger, higher energy spray droplets.

“The spray patterns produced can significantly reduce the risk of drift that ensure more of the product applied stays in the field target,” he advised.

“It is particularly important for potato blight, where any wind gusts that would shift the spray pattern of finer droplets could result in patches of the crop receiving less application and therefore lower protection from infection.”

Where weather conditions also interfere with crucial blight spray intervals, the adoption of drift reduction technology could help operators assure more timely applications.

“Over recent seasons Syngenta research operated on the independent Eurofins trials site has shown 90% drift reduction technology of the new 3D ninety nozzle, consistently outperformed conventional flat fan nozzles for blight control with Revus (mandipropamid) applications,” he reported.

In each season’s trials performance had been maximised when Revus had been applied in conjunction with Crusade/Sterling.
“The unique way Crusade and Sterling improve the consistency of size and quality of spray droplets means more product is available to reach the lower leaves,” he added.

Studies at Syngenta’s application research facility, at Jealott’s Hill in Berkshire, had previously shown the addition of Crusade/Sterling typically produced more droplets per ml of spray in the optimum spectrum for potato leaf coverage. In conjunction with an angled spray pattern, that improves targeting of lower leaves, better protection is delivered throughout the crop canopy, advocates Mr Fordham.

Last season, the Eurofins field trials were repeated, this time with Amphore Plus (mandipropamid + difenconazole). The combination of 90% DRT nozzles and Crusade/Sterling again providing the most effective overall results for blight control throughout the season.   

“Close analysis of the results, three weeks after the blight programme had been stopped, showed Amphore Plus applied through the 3D ninety was performing very well, but when you add the Crusade/Sterling in it had performed exceedingly well and better than the other nozzles on test,” he added.

In the 17 September assessment, 21 days after the final Amphore Plus application and when blight had reached 100% in the untreated, the addition of Crusade/Sterling into the tank allowed the efficacy to be further maximised, with a clear reduction in disease severity when used with the 90% drift reduction nozzles on trial.

In other intrinsic activity research by Eurofins last year, the season-long applications of Revus and Crusade/Sterling were the most effective straight CAA blight fungicide in the trials, as well as being inherently active on all common and aggressive blight genotypes.      

“The 3D ninety was the best choice in achieving the best level of disease control,” reported Mr Fordham. “The addition of Crusade/Sterling had a positive and significant impact on levels of disease control.”