Photo-selective plastic nets in young peach orchards

Present work aims to investigate photo-selective hail nets (yellow, red and blue) effects on young nectarine trees (Prunus persica L.) in a typical production area in Northern Italy (Faenza, RA), compared with black net, the most used in local orchards. The study was carried out during three years in a private orchard, from second growing season until full production. Light spectra under photo-selective nets were measured in one sunny day of the third growing season at two distances from the net and in the two sides of the row using an array spectrometer; tree growth was evaluated every year, fruit yield and quality during the second and third year. The light spectra under the nets were modified according to net color. All tested nets reduced ultra-violet A (UVA) wave length of the same extent, while blue net reduced Infra-Red (IR) significantly less than other nets. Trees under red and yellow nets had higher production as number of fruit/tree and kg/tree in the earliest two years, on the other hand trees under black nets had lower, not significant, production also in the third year while trees under blue net recovered. Net color did not significantly affect fruit quality, but yellow net induced redder skin than black net and blue net smaller fruits at least one season. Trees under blue nets had lower growth than trees under other net colors, but they did not show any photosynthetic stress. The results suggest that blue net reduced peach tree vigor as reported by previous studies in other species, while yellow and red nets improved fruit production and quality. In conclusion, photo-selective plastic nets influenced production and growth mainly in the first two years of application on young peach trees with specific and opposite results. Red and yellow induced higher production and fruit quality and blue net provoked less vigor and fruit quality.