New recommendations which should help growers optimise in-furrow applications of the popular potato fungicide, Amistar, could be on the way.

Manufacturer, Syngenta’s technical manager, Michael Tait, speaking at the Potatoes in Practice event, said that a new design of planter nozzle set up shown at the Dundee event, reduced the likelihood of clogging to a vital part of the applicator unit.

He said previous models had cone nozzles built in at both the front and back of the shoe, with that design spraying into the furrow as it was opened, before placing the seed potato, and again onto the soil as the tuber was covered. However, feedback from growers pointed out that the front nozzle could be prone to clogging with soil.

The new design, researched by Syngenta, Team Sprayers and Grimme, has a configuration that has both nozzles strategically placed to spray and mix into the soil after the potato has been planted.

“We have been doing intensive testing to see whether hollow cone or low drift nozzles work best for application, and what were the optimum water volumes, particularly on modern belt planters operating at higher speeds,” he said.

“Previously, planters were typically smaller and slower, and standard practice was to recommend the minimum possible water volumes. It was often a trade-off of the need for efficacy, with the capability of machinery.

"Today’s machines are bigger and faster, with the capacity to carry more and with growers geared up to efficiency of operations to get the best possible results. With the ability to apply at a water volume of 100 l/ha, we can potentially move towards optimum efficacy,” he added.

Application trials at the start of this season have been assessing effects of different techniques on emergence and ground cover, as well as monitoring disease.

Data from independent trials on rhizoctonia control should be available for BP2019 at Harrogate, whilst reports on diseases which develop over time in storage, such as black dot, will be released at next year’s Potato Science meetings, said Mr Tait.