Evaluation of some domestic and foreign walnut cultivars in the conditions of Bursa, Turkey

Abstract

This study was carried out to evaluate some domestic ('Bilecik', 'Maras 12', 'Maras 18', 'Sebin Sen1', 'Sen 2') and foreign walnut cultivars ('Chandler', 'Fernette', 'Fernor', 'Howard', 'Pedro', 'Serr') in the conditions of Bursa, northwest Turkey (latitude 40 degrees 11' and longitude 29 degrees 3') between 2008 and 2012. The cultivars were compared according to leafing time, bloom period of staminate and pistillate flowers, leaf fall, tree vigour and fruit characteristics. The earliest leafing was observed in the cultivar 'Maras 12' and the latest leafing were noted in 'Fernette' and 'Fernor'. First female flowers appeared at the end of April in the 'Serr' cultivar, while the female flowers in 'Fernor' appeared at the end of May. Catkins flowered between mid-April in 'Sebin' and the end of May in 'Fernor'. Flowering of 'Sen 1' and 'Sen 2' was homogamous, the flowering of 'Bilecik' was protogynous, and other cultivars were protandrous. The earliest leaf fall was observed in 'Sen1', 'Sen 2', 'Sebin', 'Maras 12' and 'Maras 18' and the latest leaf fall was seen in 'Howard', 'Pedro' and 'Chandler'. 'Sen 1', 'Bilecik', 'Chandler' 'Maras 12', 'Fernor', 'Pedro' exhibited higher vigour than other cultivars. All cultivars produced nuts in 2012. The fruit weight of cultivars ranged between 9.86 g ('Maras 12') and 16.80 g ('Sen 1'). The shell thickness varied between 1.62 mm ('Sen 1') and 2.67 mm ('Howard'). The percent kernel was highest in 'Sebin' (57.22%).