Contrasting Fruit Properties of Hazelnut Cultivars Grown on Different Rootstocks

Grafting and cultivation of hazelnut on Corylus colurna seedling have been initiated only recently, therefore practical experiences are currently considered incomplete. It is for this reason that pomological and technological properties of fruits of identical hazelnut cultivars planted on individual roots and Corylus colurna rootstock have been contrasted. The trial included 'Rimski', 'Istarski Dugi', 'Tonda Gentile Romana' and 'Cosford'. The spacing in self-rooted plants was 4 x 4 m and 5 x 4 m, in those grafted on C. colurna seedling. The trial was set up in the region of Zajecar (Eastern Serbia) characterized by high air temperatures, frequent droughts and fairly low rainfall, which is considered unsuitable for growing hazelnut. The vigorous root system of Corylus colurna resulted in larger fruits and higher fruit weight in the studied cultivars. Several-year results suggest that fruit and kernel size of cultivars grafted on C. colurna were larger, as compared with those of cultivars grown on individual roots. Average fruit and kernel weight, and kernel content were increased by 12.6% (0.49 g), 19.3% (0.49 g) and 2.5% respectively. Oil content in fruits of cultivars grown on individual roots was higher by 2.5%, whereas raw protein content was identical. Mineral matter content in the kernel of fruits of these cultivars was also higher by 0.24%.