Coloured Covering Materials for Peach Protected Cultivation

摘要

Spectral wavelength distribution and quantity of solar radiation influence plant photosynthesis, photomorphogenesis, phototropism and photoperiod. With regard to photomorphogenesis, vegetative and reproductive growth processes are influenced by the phytochrome and cryptochrome. In literature the phytochrome response is characterized in terms of radiation rate in the red wavelengths (R, 600- 700 nm) to that in the far-red radiation (FR, 700-800 nm), i.e. the R/FR ratio. The effects of the blue radiation (B, 400-500 nm) on the morphogenetic responses of plants can be investigated by studying the ratio between the blue radiation and the far-red radiation, i.e. the B/FR ratio. Aim of this paper is to investigate the influence of coloured nets on peach trees. A BLUE net, a RED net, a YELLOW net, a PEARL net, a GREY net and a NEUTRAL net were installed on greenhouses at the experimental farm of the University of Bari (Italy), latitude 41°05' N. Peach trees were located in pots inside the greenhouses and in open field. The growth of the peach trees cultivated in open field was lower in comparison to the growth of the trees cultivated under the coloured nets. The RED and BLUE nets influenced the spectrum of the solar radiation passing through the nets modifying the investigated radiation ratios. Both nets increased the growth of the trees more than the NEUTRAL, PEARL and GREY nets. The nets positively influenced the fruit characteristics, such as size, colour and sugar content, in comparison to open-field.