Evaluation of coloured nets in peach protected cultivation

The aim of this paper is to investigate the influence of the radiometric properties of coloured nets on peach tree photomorphogenesis. The modification of the spectral distribution of the transmitted radiation and thus the effects on the tree vegetative and productive activity were studied. A field experimental test using coloured nets for the protection of peach trees was carried out during 2008 at the experimental farm of the University of Bari, latitude 41° 05' N. A blue net and a red net, characterised by a nominal shading factor of 40%, and a neutral net with a nominal 12% shading factor were tested. Peach trees in open field conditions were used as control. The effects of the nets on the trees growth were correlated with the radiometric properties of the nets, which were evaluated by means of laboratory tests. The red and blue nets influenced mainly the B/FR ratio: the former net decreased and the latter increased the B/FR ratio. The nets influenced the quantity as the quality of the yield. The red net increased the shoot growth of the trees more than the blue one. The nets influenced positively the fruit weight and skin colour in comparison to the open-field.