Improved sprayer for treating by means of pesticides fruit trees and/or shrubs rows, comprising: - a support frame suitable to be coupled or belonging to a machine body of an agricultural machine; - a taking tank coupled with said support frame and suitable to contain a water and pesticides mixture intended to be sprayed on the foliage of fruit trees and/or shrubs of an orchard; - a diffuser assembly operatively connected through articulation means with said support frame and composed of a pair of distribution pendants (6, 7) facing each other, at least one of which is provided with spraying nozzles suitable to spray in a nebulized way said water and pesticides mixture on said foliage of said trees and/or shrubs, said distribution pendants (6, 7) being suitable to take an operating position in which they are facing from opposite sides each of the rows of said orchard, spaced apart each other in such a way as to define a movable tunnel in which consecutive sections of each of said rows are progressively received while said agricultural machine advances on the ground in which said orchard is planted; - first moving means suitable to position said diffuser assembly at each of said rows; - second moving means, suitable to space apart each other said distribution pendants (6, 7) of said diffuser assembly so as to position said distribution pendants (6, 7) in said operating position; - ventilation means, communicating with said taking tank and having at least one outlet (11, 12), operatively connected with actuation means and suitable to produce a flow of pressurized air which conveys said water and pesticides mixture to said diffuser assembly; - at least one distribution pipe (13, 14) connected at a first end (13a, 14a) with said outlet (11, 12) of said ventilation means and at a second end (13b, 14b) with an inlet (15, 16) defined in at least one of said distribution pendants (6, 7), said articulation means including a vertical mechanical group which develops along a longitudinal axis, characterized in that said vertical mechanical group is operatively connected through rotation means with third moving means which make it rotating around said longitudinal axis in such a way that said operating position of said distribution pendants (6, 7) is defined alternately left and right with respect to the running direction of said agricultural machine on said ground in which said orchard is planted and said distribution pendants (6, 7) are placed alternately left and right with respect to said running direction. - a support frame suitable to be coupled or belonging to a machine body of an agricultural machine; - a taking tank coupled with said support frame and suitable to contain a water and pesticides mixture intended to be sprayed on the foliage of fruit trees and/or shrubs of an orchard; - a diffuser assembly operatively connected through articulation means with said support frame and composed of a pair of distribution pendants (6, 7) facing each other, at least one of which is provided with spraying nozzles suitable to spray in a nebulized way said water and pesticides mixture on said foliage of said trees and/or shrubs, said distribution pendants (6, 7) being suitable to take an operating position in which they are facing from opposite sides each of the rows of said orchard, spaced apart each other in such a way as to define a movable tunnel in which consecutive sections of each of said rows are progressively received while said agricultural machine advances on the ground in which said orchard is planted; - first moving means suitable to position said diffuser assembly at each of said rows; - second moving means, suitable to space apart each other said distribution pendants (6, 7) of said diffuser assembly so as to position said distribution pendants (6, 7) in said operating position; - ventilation means, communicating with said taking tank and having at least one outlet (11, 12), operatively connected with actuation means and suitable to produce a flow of pressurized air which conveys said water and pesticides mixture to said diffuser assembly; - at least one distribution pipe (13, 14) connected at a first end (13a, 14a) with said outlet (11, 12) of said ventilation means and at a second end (13b, 14b) with an inlet (15, 16) defined in at least one of said distribution pendants (6, 7),