GLASS MICROSPHERES COVERING FILM: AGRONOMIC EVALUATIONS ON THE PRODUCTION OF CUT FLOWERS

A trial was carried out to evaluate, in the north-centre of Italy, the behaviour of a new plastic covering film able to scatter light ('diffract light'), prepared with the inclusion of empty glass microspheres ("Solex"). The new film was compared to a covering 'diffused light' film ("Agrilux"). Both films had a co-extruded three layers structure, with the same content of Vinyl acetate. They were tested in two different conditions (cold tunnel and air conditioned greenhouse), working on two species of cut flowers, Limonium (Limonium sinuatum Mill.) and three cultivars of carnation (Dianthus caryophyllus L.). Moreover, the development of some physical and mechanical characteristics of plastic films were checked. Since the first results, the innovative film showed a better behaviour than the control one. It presented 'light' and 'thermal' conditions (lower temperature during the day and slightly higher temperature in the night, compared to the control film) that allowed a better growth and yield respect to the control. In fact, Limonium grown under the glass microspheres film showed higher yield and better commercial quality (stem length). The analysis of cumulative production in carnation showed different results among cultivar. For cv. Luisa and Dandy, the positive effects of glass microspheres film were more evident during autumn and winter, while in cv. Michelle, those effects were higher during warm seasons (October, April, May and June). This could be explained with the fact that the glass microspheres film provides environmental conditions that avoid some of the stresses plants undergo during some stages of their cycle.