Micron’s range of hand-held spinning disc Controlled Droplet
Application (CDA) sprayers have been used in European forestry for
over 20 years. Equivalent weed control can be achieved with
CDA sprayers at 10 – 30 l/ha total spray volume compared to
the 200 l/ha required with traditional high volume knapsack
sprayers. The low volumes allowed by the precision of CDA
give substantial logistical advantages as well as reducing the
weight carried by the operator in difficult terrain.
Micron’s HERBI sprayer range is used widely in the UK and in
Scandinavian forestry, and the Micron ULVA sprayer range has been
used for control of bracken, heather and woody weeds on
inaccessible slopes.
The precision of application with spinning disc sprayers for
herbicide application offers various advantages in addition to
logistical savings. The production of relatively large (200
– 300 micron) even-sized spray droplets by the Micron HERBI
range minimises any risk of spray drift, with precise spray
placement of great importance in situations where there are nearby
crops. The elimination of the waste inherent in spraying with
hydraulic pressure nozzles also ensures maximum efficiency of
chemical usage, allowing use of minimum dose rates.
In some areas Micron sprayers have been modified to suit
local requirements better. For example, by using innovations
based on Micron HERBI and HERBAFLEX spray heads, foresters in Chile
have obtained excellent weed control in eucalyptus with glyphosate
and reduced the generation time by two years (planting to harvest),
a notable achievement in this naturally fast maturing tree,
allowing eucalyptus to be profitably felled over just 8 years of
growth as opposed to the normal 10 year period. Accurate and
cost effective weed control curtails weed competition and allows
the trees to make full use of available soil, water, nutrients and
solar radiation.
Trials are also being conducted in eucalyptus in South America with
standard Micron HERBI-4 sprayers and HERBIs are being successfully
used in Africa in agro-forestry projects. The UK
Forestry Commission has published Technical Information sheets on
Micron’s HERBI-4 and ULVA+ sprayers.
Tractor mounted sprayers using Micron rotary atomisers have also
been developed in the UK for use in forest nurseries and similar
applications.
Micronair atomisers are widely used for aerial spraying of forests
in North and South America, Eastern Europe and elsewhere. The
narrow, controlled droplet spectrum produced by these atomisers is
ideal for the application of Bts and Insect Growth Regulators
(IGRs) as well as chemical insecticides. Micronair AU5000
atomisers are recommended for general contracting work, whilst the
AU4000 is preferred for use on dedicated forestry aircraft,
especially when fine droplets are required for the application of
Bts and similar formulations. Electrically driven AU6539
atomisers should be used on helicopters operating at a low or
varying airspeed.