Phenological and pomological properties of promising walnut (Juglans regia L.) genotypes from selected native population in Amasya Province

Abstract

Walnut production in Turkey fluctuates quantitatively and qualitatively. The main problem is almost always early leafing. The environmental adaptations of Turkish national walnut cultivars are often poor due to early bud break and sensitivity to walnut blight and anthracnose. Therefore it is necessary to carry out a breeding programme for developing new cultivars in Turkey. This study was conducted out to determine genetic variability and select superior walnut types within seedling population of Amasya Province. During the study, 5000 walnut seedling trees were evaluated for late flowering, lateral bud fruitfulness, blight and antracnosis tolerance and high quality fruits. In term of high yield capacity in lateral branch and late leafing, 20 walnut types were selected. The vegetation cycle begins mainly in the second and third decade of April. In the selected genotypes, nut weight ranged from 7.46 to 15.21 g, kernel weight ranged from 3.73 to 7.44 g and kernel percent varied from 46.15 to 63.16%. The kernel of selected types was light colored. Among selected walnut types, the percentages of lateral bud fruitfulness were determined between 30 and 70%. Selected walnut genotypes will be used for further breeding purposes in terms of yield capacities, nut characteristics, and cold hardiness.

Key words: Lateral bud fruitfulness, late leafing, nut quality, bacterial blight, anthracnose.