Innovative photoselective plastic films for protected cultivation of fruit trees

In order to assess the photoselectivity of covering materials, four plastic films were tested in laboratory and under natural radiation evaluating R/FR and B/FR ratios. These films were: an experimental ethylene vinyl acetate (EVA) photoselective film obtained by adding ultra violet (UV) stabilisers characterised by titania (PS); a film obtained by using copolymers of EVA featured with a specific photoselective screen giving an effect of reducing the plant shape and development (CLARIX Blue); an EVA film with high VA content characterised by total transmission of UV radiation (PATILUX TUV); an EVA photoselective film used for the protected cultivation of nectarines (IR Diffusive). The photoselective films tested for their potential use in orchard protection induced lower R/FR and B/FR ratios than characteristic of unaltered solar radiation. All the R/FR ratios of the tested films decreased slightly while the B/FR ratios decreased significantly for two of the photoselective materials (IR Diffusive film and PS film). The development of plastic films capable of modifying quality of radiation transmitted and of influencing the photomorphogenesis of the fruit trees by reducing vegetative elongation has potential economic benefits for fruit growers, due to decreased pruning costs and improved fruit quality