THE EFFECT OF PHOTOSYNTHETIC ACTIVE RADIATION ON YIELD AND QUALITY TRAITS IN 'TOMBUL' AND 'PALAZ' HAZELNUT CULTIVARS

Abstract

This study was carried out to determine the changes in yield and some quality characteristics of 'Tombur and Palaz' hazelnut cultivars according to orchards varied in terms of photosynthetic active radiation. The study was carried out in three orchards with full day sun lighted (100% PAR), half day sun lighted (66.34% PAR) and shady (49.93% PAR) in the Fatsa district of Ordu province (Turkey) in 2016. The experiment was designed in random blocks and three replicates. As a results, it was determined that lighting conditions of the orchards have a significant effect on yield and quality traits in both cultivars. As the sun lighting decreased, yield and good kernel rates decreased; blank nut ratio increased. In addition, the oil content was decreased as the lighting in the orchards increased but it was found to be significant only in 'Tombul' hazelnut cultivar. As a result, it may be recommended to take into consideration the natural lighting conditions of the orchards in the new plantations, not to plantation the orchard in places that do not have any sunlight and to apply the cultural practices in existing orchards to get enough light.