Effects of Branch Number on Quality Traits and Yield Properties of European Hazelnut (Corylus avellana L.)

Tuba Bak,Turan Karadeniz

doi:10.3390/agriculture11050437

Abstract

Despite being the world leader in the production of hazelnuts, Turkey’s nut yield per hectare is quite behind other producer countries. The main reasons for low yield are the completion of the economic life of hazelnut orchards and the lack of pruning following the technique. Hazelnuts are being grown with the ‘ocak’ system in Turkey. The ocak system is a bush-like growing technique that does not contain the main trunk but consists of shoots instead. It is necessary to maintain the optimum number of shoots per ocak to increase yield and quality in this system. The effects of different branch numbers on yield and fruit quality parameters of ‘Tombul’ and ‘Palaz’ hazelnut cultivars were investigated in Ordu ecological conditions. ‘Palaz’ had the highest yield per ocak in 8 branches (1460.19 g), while ‘Tombul’ had in the 5 branched ocak (2170.47 g). ‘Palaz’ and ‘Tombul’ had the highest fruit weights in 4 and 4–6 branches, respectively. The highest oil ratio of ‘Palaz’ was observed in 4 branches, while ‘Tombul’ had the highest in 5 branches. The highest kernel ratio was determined in 6 and 5 branches in ‘Palaz’ and ‘Tombul’, respectively. The ocaks with 4 and 5 branches were mostly expressed higher values, and it is foreseen that the number of branches should not exceed 6 to reduce the competition of the branches and to obtain good quality products.

Highlights

Hazelnut is one of the important Turkey-originated fruit species
The yield of ‘Palaz’ ranged from 1024.66 g (5 branches) to 1460.19 g (8 branches) and the yield of ‘Tombul’ was 737.82 g (10 branches) to 2170.47 g (5 branches) (Table 1). Yield fluctuated in both cultivars according to years, as the number of branches decreased, the yield increased in general (Figure 2)
Poor soil conditions, climatic conditions, fertilization, and irrigation status of orchards were some of the main causes of yield differentiation

Summary

Introduction

Hazelnut is one of the important Turkey-originated fruit species. Turkey has quality cultivars and suitable areas for hazelnut production. The Black Sea coast is the most suitable area in terms of ecologic conditions for hazelnut cultivation within these limits [1,2,3]. Ordu province is the leading producer province in Turkey with 217,000 t [5] and provides 27.97% of production by itself [6]. Turkey is dramatically behind the other hazelnut-producing countries in terms of nut yield despite being the leading hazelnut exporting country. It ranks 10th with 64.2 kg·ha−1 yield while the USA has 269 kg·ha−1, France has 221.3 kg·ha−1, and China has 197.9 kg·ha−1 yields. The husks are generally 2.5 times the length of the fruit [20]

Method

Experimental Design

Results and Discussions