EFFECTS OF GIRDLING AND COVERING MESH ON RIPENING, COLOR AND FRUIT CHARACTERISTICS OF ITALIA GRAPES

The effect of single and double girdling, and covering by mesh on the ripening, colour and fruit characteristics of 'Italia' grapes was exam ined. Three types of girdling were studied: girdling after fruit set, girdling at the beginning of ripening (veraison) and double girdling ( girdling at fruit set + girdling at veraison). Girdling after fruit se t significantly increased both berry weight and yield. Girdling at the beginning of ripening significantly increased soluble solids, the mat urity index and berry colour, decreased titratable acidity and advance d fruit ripening by 5 d. Double girdling significantly increased berry weight and yield and produced the best results as regards soluble sol ids, maturity index, berry colour and earliness. Covering the vine wit h mesh delayed ripening by 9 d, decreased soluble solids, the maturity index and berry colour, although the yield was higher than that of th e control because bunches were bigger and had more berries. Analysis o f covariance showed that the delay in fruit ripening caused by mesh wa s not only due to an increase in yield but to other unmeasured factors probably associated with changes in microclimate.