Photo-selective hail nets affect fruit size and quality in Hayward kiwifruit

The aim of the present research was to verify if photo-selective hail nettings can be used to affect fruit quality at harvest and during cold-storage, in addition to hail protection. The study was carried out in Southern Italy on 7-year-old Hayward kiwifruit vines. Four types of photo-selective hail nettings (blue, grey, red, and white) were compared with an un-netted control. The nettings affected differentially and significantly most of the qualitative parameters measured in this study. Both the white and the red nets appeared to be very interesting because they allowed a high dry matter accumulation in the fruit. This was translated into a high soluble solids concentration in the fruits during cold-storage. The blue and grey nets tended to affect negatively the percentage of dry matter and soluble solids content of fruit. This may be due to shading effects. In addition, the white and the blue nets had a slight negative effect on flesh chlorophyll concentration and colour. All the tested nets decreased polyphenol concentration and antioxidant activity of the kiwifruit at harvest. It is proposed that in case hail protection is a must, the right choice of photo-selective hail nets can lead to additional benefits, making the netting more cost-effective for the growers.