ULVA Chemical spraying course Achnashellach
Photograph courtesy of Bill Rayner, Tibbermore, who has provided some information on the course.
Worker Trainee from NE Scotland (Name?) at an ULVA 2.4-D heather spraying course being run by Mike Cheesewright in Achnashellach Forest, Wester Ross in August 1974.
This is a view of the very fine chemical and oil mixed spray which came off the ULVA sprayer. The sprayer consisted of a two plastic cones which had very fine serrations on the outer edges and were spaced a little apart on an axle driven by an electric motor. The motor was powered by a series of U2 batteries housed in the handle and was required to run at something like 7000 revs to work properly. The liquid was fed from the bottle by gravity onto the centre of the disc cones and centrifugal forces spun it out towards to the edges and off the serrated tips in very small sized droplets.
Ideally it was applied by walking across the wind and allowing the spray to drift sideways over the area to be treated in a format known as incremental spraying. ULVA was an abbreviation for Ultra Low Volume Application and referring to volumes less than 10 litres to the hectare?
Problems were numerous such as too much wind, rain, keeping a steady pace and in straight lines, batteries running low and rev speed dropping, serrated edges damaged by touching the hard vegetation such as heather.
However the system worked very well on aircraft fitted for spraying crops and insects killing forest trees.
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