The aim of this investigation was to evaluate one of the
techniques for recycling on tunnel sprayers and it was
made on a prototype which shows a fair margin of
improvement. This technique was compared with a traditional
system consisting of a commercial sprayer, properly
calibrated and set, according to the actual operative
conditions, without introducing a large number of variables.
However, the results make it possible to draw some
general interesting conclusions.
The most interesting result is that this sprayer has the
peculiar characteristic of a tunnel spraying system and
some others typical of the air-blast system. In fact, compared
to the previous research on tunnel sprayers, a great
improvement was obtained as to penetration of the foliage.
This important result, that largely overcomes the
inadequately the traditional equipment, was reached by
means of the high power of the axial fans and of the
intense air circulation between the shields.
Notwithstanding this complex management of the air-
#ow, the sprayer showed a good reduction of losses and
a good e$cacy of recycling: the amount of recycling
represents most of the product o!-target. This is important
for reducing the active ingredient sprayed, the risk of
contamination, and the damage to orchards and "elds
adjacent to the treatment area.
Another relevant peculiarity that distinguishes it from
other tunnel sprayers is the dimension, that allows the