Experimental setup to evaluate the water permeability index of agricultural nets

A system made of textiles able to protect cultivations from the damages of rain fall and to let pass through, could increase the yield and quality of the production and the reliability of predictions for the harvesting of many fruits such as cherries. To this purpose a test device was designed and set up at Arrigoni S.p.A. to simulate and measure the rain permeability of agricultural nets at different inclinations, in terms of water amount reduction passing through the net when exposed to the rain. Rain permeability index of the net was defined as the ratio between the water sprayed by the nozzles and the water gathered into the container under the net sample. Nets with different geometrical characteristics characterized by having low porosity were tested. Since the porosity could be of little significance to describe the agrotextile, water permeability was correlated with the air permeability of each sample measured in a micro wind tunnel. The first results allowed to understand the influence of the main parameters on water permeability of the nets. The mesh size, the inclination of the net and the use of the double layers scheme of the protection system were found to give the most significant change to the rain permeability behaviour of the nets.