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Square metre success

David Betts, Norfolk based Agronomist

David Betts, Agrovista, uses square metre in agrochemical use training

David Betts finds scaling spray application done to a square metre makes his point more powerfully.

David Betts is an agronomist for Agrovista based in Norfolk. Each year he runs 10 training events for sprayer operators as part of their professional development.

“For the last series of training sessions I wanted to show how important it is to have good plant coverage with the crop protection product. I searched for ideas on the internet but struggled to find anything that made the point I was looking for.

I remembered seeing someone using a square metre to help show how farmers grow crops. I did some calculations and came up with this example;-

For spraying a wheat crop with herbicide to control blackgrass for each square metre we would use active ingredient equivalent in size to 1 grain of sand which is then mixed with 1 drop of an adjuvant to help it mix with 4 teaspoons of water.

With a table that was 2 square metres in size and using a teaspoon I can easily show what a careful job a sprayer operator does, spreading such small quantities evenly over every square metre in a field.

I could also show why rainfall after spraying is a problem. If there is just 1 mm of rain it’s the same as tipping a 1 litre jug of water over the square metre. Which illustrates why timing is so important so as not to allow rain to wash off all the pesticide.”