95 Bulletin UASVM Agriculture, 67(1)/2010 Print ISSN 1843-5246; Electronic ISSN 1843-5386 Study Regarding the Air Speed Created by the Axial Fan of the Orchard Spraying Machines Ioan DROCA 1) , Ovidiu MARIAN 1) , Ovidiu RANTA 1) , Adrian MOLNAR 2) , Sorin STĂNILĂ 2) , Mircea MUNTEAN 2) 1) Faculty of Mechanics, Technical University Cluj-Napoca, B-dul Muncii, Cluj-Napoca, Romania 2) Faculty of Agriculture, University of Agricultural Sciences and Veterinary Medicine, Calea Mănătur nr.3-5, Cluj-Napoca, Romania; e-mail: adimolus@yahoo.com Abstract. The paper has studied how the speed of air is changed at different distances from the circumference of the fan and at various heights at the distance between rows of 3 m, using ATOM 1000 orchard sprayer machine. Experimental tests have shown that airflow speed changes along the circumference of the fan depending on the distance and position. The direction of rotation of the fan in a clockwise direction influences the airflow speed, being higher on the right side. When measuring vertical airflow velocity (3m distance between rows), there can be observed a slowing of the airflow speed along winth height, maximum speed is at 1 m above ground. Also here can be observed that the speed of airflow in the right side is higher on all points measured. Keywords: airflow speed, axial fan, wind speed distribution. INTRODUCTION The chemical spraying is still one of the most used methods for weed and pest control despite all the progress made in the field of spraying and the biological researches in order to obtain new varieties tolerant to pests. The practice activity shows that the chemical method for weed and pest control in used before its high efficiency, low cost and for its multiple application possibilities. The new substances used in pesticides have a low remanence, some of them are biodegradable, they are less toxic for other species, and they are selective and much stronger. In order to obtain an efficient treatment it is needed to modernize the application methods for reduction of pollution. The losses of active substances because of drift and evaporation have a negative influence over the economic efficiency and leads to environmental pollution. From those presented above results the need to complete the set of machines and equipment with which it is possible to dosage and to apply the treatment substance on the plant only uniformly without loss, thus ensuring minimal environmental pollution. Falling in this context the present paper addresses the study of how air flow rate varies at different distances on the circumference of the axial fan of ATOM 1000 orchard sprayer, and airflow velocity variation with height on the rows with 3m distance.