Abstract
The anti-hail nets are widely used to protect apple fruit against hailstorms and hail damage. They can have also beneficial effects against pests in apple orchards, in particular codling moth (Cydia pomonella). However, covering the trees with anti-hail nets can modify the orchard microclimate and reduce the interception of light, thus potentially causing negative consequences on the organoleptic quality of apple fruits.
A consistent reduction of the percentage of apple fruits infested by codling moth was registered as a result of the use of anti-hail nets during two consecutive harvest years. Their use did not affect fruit maturity, but reduced the skin colour, sugar content, pulp total phenol content, volatile compound composition and sensory characteristics. However, the results were inconsistent over the two years apart for total phenols, formation of two volatile compounds (butyl and hexenyl acetate, the first being one of the main odorants in most apple cultivars), sensory attributes of 'flavour of lemon' and 'juiciness'. For these parameters, the fruits from plots where the trees were not covered showed higher values than those from plots where anti-hail nets were used.
The use of anti-hail nets was effective in preventing the attack of codling moth to apple fruits, suggesting their use in organic management where conventional insecticides are prohibited. Under the conditions tested, anti-hail nets showed a negative effect on some of the quality characteristics measured on apple fruits, which could influence consumer acceptability.