SUMMARY
The North Patagonian Region is the largest growing producing area of
apples and pear of the Southern Hemisphere and also represents the main
economic resources of the area
The increasing cost of sanitary control, the incidence of key pest
Codling moth (Cydia pomonella, L), the size of tree (between 4 and 6 m tall),
weather conditions where prevail low humidity and high intensity winds, and the
increasing environmental pressure whit regard to pesticide use, justify a study
to badly improve the efficiency of pesticide applications.
In modern pomology, the study of new sprayer design to optimize
pesticide delivery to fruit crops is a must. The aim if this research where: 1) to
study methodological approach to test orchards sprayers. 2) to compare the
efficiency of application between a conventional air-carrier, axial-fan sprayer
and a cross flow sprayer (whit 4 cross-flow fans) whit two volume rates,
standard and 20 % reduced.
The results clearly showed that the best performance was obtained
with the cross flow sprayer.
Generally speaking, it is apparent that the control of Codling moth is
more difficult in the interior of the canopy than outside the canopy, as percent
damage is near twofold. However under those conditions the cross flow
sprayer showed and acceptable and uniform pesticide coverage inside the
canopy and also at different tree height, (top, middle and bottom)
At the highest rate, the microdistribution of the cross flow sprayer
application was the most uniform in the canopy.
The better spray distribution of the cross flow sprayer provided a good
control of codling moths even at a reduced volume rate.
The cross flow sprayer allows to reduce exodrift losses beyond the top
of the trees between 5 and 8 fold. However the drawback was increased
endodrift in the alleyways.
New methodological approaches are discussed in relation to spray
application evaluations.
Key Words: Orchard sprayer; Air-carrier sprayer; cross flow sprayer; Cydia
pomonella (L.); Malus domestica, Borkh