Operators change tactics for better pre-em sprays
Ample soil moisture levels are set to help achieve good results from pre-emergence herbicide treatments this season, however persistent strong winds and soil conditions are proving a serious headache to get applications made at the optimum timing.
A new Syngenta survey of sprayer operators has shown that over 95% are intending to adapt pre-emergence application techniques this season, to minimise spray drift risk and look to improve herbicide results.
The use of 90% Drift Reduction Nozzles appears more imperative than ever, advocated Syngenta Application Specialist, James Thomas.
“Sprayer operators can further reduce the risk and ensure that more spray hits the target by following the advice to Go Slow; Go Low and Get Covered,” he added.
Initial results of the survey of more than 50 sprayer operators’ pre-emergence application techniques for this season indicate that whilst the average operating speed had been 11.3 km/hr, around 20% have been exceeding the 12 km/hr maximum that trials have shown could significantly reduce drift risk and enhance levels of desired Black-grass control.
Furthermore, 15% of sprayer had been operating at a standard boom height of 60 cm or more - in instances up to 80 cm. “Lowering boom height to 50 cm above the target soil surface can prove the biggest single factor in reducing drift and optimising soil surface coverage,” reported James. “Allied to boom height, if operators slow down to less than 12 km/hr it can hugely improve boom stability and help to ensure consistent height with an even spray pattern.”
He believes that nozzle choice can also make a big impact on ensuring spray reaches the target soil surface. The survey showed that over 55% had been using Syngenta 3D Nozzles for the majority of their pre-emergence applications, but nearly 20% were still operating with standard flat fans. Less than 10% had, hitherto, been using drift reduction nozzles.
“Historically, operators have avoided low drift nozzles for pre-emergence applications. However, our Black-grass trials have shown that new nozzle designs, operated at appropriate water volume and speed, can achieve control levels as good, if not better, than 3D Nozzles,” he commented.
“The 3D Nozzles remain an excellent choice in perfect spraying conditions, but if conditions are in any way compromised, the advice is to switch to 90% drift reduction nozzles,” he advised. “Our application trials have shown that flat fan nozzles really have no role for pre-emergence treatments.”
To achieve optimum results James advocated the use of a 90% drift reduction nozzle, such as the Teejet TTI 110-05 - available to all growers at half price from Syngenta this season - set at 50 cm from the soil surface and operated at 2.0 bar, to deliver a water volume of 200 l/ha at 10 km/hr.
“That combination appears to give the best possible results for Black-grass control and practical in-field application to get around the farm at the optimum time.”
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James’ essential Rules for Pre-Emergence Herbicide Application are: