DESIGN AND USE CRITERIA OF NETTING SYSTEMS FOR AGRICULTURAL PRODUCTION IN ITALY

At the moment, there is a large number of agricultural net typologies on the market characterised by different texture features such as threads, texture, dimensions of fibres and meshing, physical properties such as weight, colours, shading factor, durability, porosity, air permeability and mechanical characteristics such as stress, strength at break and elongation. Protection from hail, wind, snow, or strong rainfall in fruit-farming and ornamentals, shading nets for greenhouses, or nets for moderately modifying the microenvironment are the most common applications. A systematic review of the current state-of-the-art of structural parameters, standard and regulations, most common agricultural applications of nets and their supporting structures has been developed by means of a literature study, technical investigations, interviews with permeable covering producers, specialised greenhouse builders and growers, who are familiar with permeable cladding applications. The interviews were based on questionnaires concerning characteristics, use and disposal of nets. As a result, the survey highlighted that in many cases different, not even similar, net typologies were adopted for the same application and the same cultivations by various growers. Results show that neither growers nor net producers have clear ideas about the relationship between the net typology optimisation for a specific function and the construction parameters of the net. The choice still depends often on empirical or economic criteria and not on scientific considerations. Moreover, it appears that scientifically justified technical requirements for nets used in specific agricultural applications have not been established yet.