Sprayer set up is vital

Pre-emergence herbicide treatments create one of the biggest challenges for effective application. With no crop to intercept the spray, extra care must be taken to avoid drift, and to achieve even distribution of droplets on the soil surface to maximise efficacy. Trials at Barton and Doncaster last autumn have reconfirmed our previous findings around techniques to balance efficiency, efficacy and environmental impact.

90% drift reduction nozzles deliver more even distribution of spray droplets

Nozzle choice is a fundamental part of hitting the target and achieving effective coverage of the soil surface – to get the best control from all pre-emergence applications. Ensuring an even distribution of product over the soil surface will improve your chances of controlling the emerging grass and broadleaved weeds.Both good coverage and even distribution are necessary for maximum efficacy of your pre-emergence herbicide application. The graphics on the left hand side both illustrate 50% coverage. However, the drift prone nozzle is showing extremely uneven distribution of the coverage, so we would likely see uneven and poor levels of control.

200l/ha water volume provides more consistent results

Grass weeds are getting tougher to control. Trials over four years have demonstrated that 200 l/ha water volume provides more consistent levels of control, with an average of 10% higher efficacy compared with 100 l/ha.

Download the Spray Assist app

Syngenta Spray Assist is a new app created to help sprayer operators to select the most appropriate application techniques on-the-fly. The simple to use app links to live local weather data to analyse the factors that influence accurate application and potential risk of spray drift, including wind, rain or frost. The app suggests techniques to enable sprayer operators to mitigate risks or alter practices.


1. Consider crop competitiveness when choosing your crop.

2. Get your pre-emergence application on as quickly as possible.

3. Ensure 50cm boom height and maximum speed of 12km/h.

4. Adopt 90% drift reducing technology.

5. Map your fields with a traffic light system - most 'tough' sites will need 200l/ha water volume for best grass weed control. Where timing is under pressure, balance efficacy by using 100-150l/ha on lower pressure fields.

6. Download the Spray Assist app.

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