Based on a long history in Turkey, hazelnut continues to be the traditional export produc,t and it has important contributions to the national economy.1zx

Between the hazelnut producng countries, we are in first place in terms of production and exports. However, in terms of product units, we are behind other manufacturer countries. The fluctuations in the hazelnut production in our country emanate from the uncontrolled growth of the production areas.

Hazelnuts has been widely used in bakery and confectionery industry, like it is consumed as appetizers. There are many production and marketing problems of hazelnut. The biggest problem of production is actually the low efficiency of hazelnuts. The most important reason for this low efficiency is absence of technique application systems, such as pruning and fertilization. The most important marketting problem is the creation of stocks when hazelnut is not exported that year.

1 Hazelnut Cultivars in Turkey

Hazelnut types in Turkey are collected in 3 groups according to fruit shape and features

2 Climate and Soil Requests

2.1 Climate

It is the moist and gentle cilmate regions where the hazelnut develops, and gives plenty of products. Black Sea coastal region, in terms of hazelnut cultivation, has the most suitable climatic features. Although semi-moist, dry climate regions are also suitable for hazelnuts, insufficient rainfall requires irrigation.

Hazelnut can be raised 750 m height and 60 km from the coast of Black Sea Region. Hazelnuts grow in the region where the annual average temperature is 13-16 °C. Moreover, the lowest temperature in this region should be -8, -10 C and maximum temperature should not exceed 36-37 C. The total annual rainfall should be above 700 mm and rainfall distribution should be monthly balanced. Besides, proportiional moisture in June and July should not fall below 60%.

2.2 Soil

Hazelnut roots don't go to the depths of the soil, and in the sloping fields it can reach 80 cm soil depth of land. Although hazelnuts are not very selective about the soil, they show good improvements in the rich and deep soil with humus-ting.

3 Hazelnut Farming Techniques

3.1 Land and Soil Preparation

Land and soil preparation of hazelnuts needs to be done in a careful manner before planting. Hazelnut orchards can be established on lands where either annual crops or multi-annual crops are grown. 

3.1.1 Soil-Water Protection Measures in Flat Lands:

Implementation of new plants in hazelnut orchards is easier in the flat land, but there are some different applications according to the level of water.

3.1.2 Soil-Water Protection Measures in Inclined Lands:

The land, sloping more than 5%, should be terraced in order to have a formal planting, to store the rain water, and to make the harvest, pruning and fertilizing easily. One of the following terracing systems is applied according to the slope of the land:

1. Canal Terraces: 5-25% slope

2. Trench Terraces: 25-75% slope

3. Pocket Terraces: More than 75% slope, or it can be used when other terraces are not applicable

3.1.3 Soil Preparation

The following applications should be made for soil preparation.

• Soil Analysis: For fertilizing, determining the acid level of the soil, and determining the amount of lime that will be applied.
• Doing 'Kirizma' to Soil: Cultivating the soil deeply. With 'Kirizma', sub-soil is ventilated, microbial activity is increased, and the physical and chemical structure iof soil s relatively corrected.
• Removing the Soil Fatigue: If the soil is processed for many years, fatigue can occur. To resolve this exhaustion, soil should be left to rest.

3.2 Variety Selection

 Variety selection is important:

• To ensure efficient and quality.
• To have the high-priced types from the market.
  
• To have a standardization of types in the garden.

3.3 Sapling Selection and Preparation for Planting

Hazelnut is plant that forms the stool. The stool should have the following features:

• The stool should be ripe, disease-free, and positioned to sun light.
• Stools should have well-shaped buds.
  
• Stools should also have well-shaped roots.
  

After selecting the stool, it should be removed with a small hoe without giving any harm to roots. Saplings should be cut in approximately 35-40 cm. with a sharp scissor. These prepared saplings should be planted to the planting holes without waiting.

3.4 Planting and Cultivation Systems:

The most appropriate time for planting is in autumn months. Generally, in hazelnut cultivation, 'ocak' planting system is the most common one. It is usually the traditional system in the hazelnut production area. There are 2 different planting systems:

• Hedge Planting System
• Ocak Planting System

3.5 Pruning Techniques

Planting of saplings is one of the cultural practices providing positive results to ensure development, increase productivity and extend the economic life. 

• The sapling will be shaped, and ill will protect its form this way.
• Abundant and high-quality products will be provided.
• It will prevent the mixing of excessively growing branches, and harvest operations and agriculture wars will become easy.
• With removing the diseased and old  branches, 'ocak's will have a crown shape.
• Productivity declines will be avoided by removing the foreign trees in the hazelnut grove.
• The exploitation of the nutrients will be avoided by cleaning the stool every year.

3.6 Pruning Time

Generally, the pruning time for hazelnut is in autumn. Pruning the hazelnut should start when the vegetation stops and when the leaves begin to fall.

These are the tools for pruning.

• Pruning saw
• Pruning shears
• Çepin

3.6.1 Pruning Technique Shaped By The Cultivation System

The saplings that are shaped by the cultivation system given in first 5 years, enter the age of productivity, and this reaches to its peak after 12 years. This high productivity continues until teh age of 20-25. In this age of productivity, every autumn,  broken, wounded and diseased browse with branches falling into each other is cut with hazelnut scissors.  Browses shorter than 10cm, and small branches are diluted to improve the quantity and length. So, annual prunning techniques are applied to re-create the physiological balance.

3.6.2 Pruning Technique in Public Gardens, Not Shaped By The Cultivaton System

Because of the fact that the public gardens are not shaped by the proper plantation and cultivation system, it creates haphazard branching.

• These manufacturer gardens are planted frequently, and aging.
• The number of branches in ocak is more than desired.
• Inside of ocak is closed, and it is not sufficient for ventilation and sun.
• Growing of the branches in ocak is irregular, and there is an age difference between them. So, branches brake and their eyes falls down.
• Diseased, dry, and old branches are cut. And the stool, that is produced for years, loses its function.

In these types of gardens, the work should be started by removing 'ocak's before pruning for widening the distance between them. The number of branches should be reduced to 6-8, and one of the aging, dry, diseased and mixed branches should be cut with the pruning saw, and should be covered with grafting wax. The empty sides of ocak is filled and cleaned by improving the stool. The main branches is handled one by one, and the diseased, aged and deformed ones are cut with the pruning scissor. Long and strong stools are left,but the short and weak ones are cut and diluted. Thus, with fertilization, physiological balance will be established.

If there is some weakening in the development of stools and branches, then establishing the physiological balance becomes difficult by pruning and fertilizing.

3.6.3 Stool Cleaning:

The tendency to provide stools in high for hazelnut. Every year, there is an abundant development on the main branches. These improving stools make prfit from the nutrients of ocak, causes the branches to become dense, and blocks the sun and prevents the ventilation. For this reason, the number of yearly planted branches should be constant, and they should be cleaned at least twice a year such as in autumn, and at the beginning of June or the end of May.

3.7 Fertilization

Fertilization is very crucial in the cultivation of hazelnuts for the healthy development and efficiency of the saplings.

3.7.1 Fertilizing Principles:

The benefits of feritlization can be seen by the determination of the incomplete nutrients in soil. Soil and leaf analysis has to be made for determining the nutrients needed for the normal development of the soil.

Fertilization in new planting hazelnut gardens(0-5 age): To improve the soil in organic-matter, 3-5 tons of fertilizer per decare, and recommended amounts of lime should be homogeneously distributed and hoed. Moreover, as the basic fertilization, recommended types and quantities of fertilizers with phosphorous and potassium should be mixed and added to the sapling holes. 

40 grams of nitrogenous fertilizer should be given from the first year, after the main fertilization before planting. In this way, with the first 5 years of fertilization, the desired stool development in hazelnut saplings can be provided.

Fertilization in Hazelnut Gardens at the Age of Efficiency: The normal development and fertility of hazelnut can happen with the nutrients obtained from the soil. The most important nutrients are nitrogen, phosphorus and calcium. Although the others are as much important as the mantioned ones, they are not as crucial as them.

Calcification in Hazelnut Gardens at the Age of Efficiency: The normal development of hazelnut can be established, and is able to provide abundant product in the soil between 5-7 Ph. However, in the Black Sea region, hazelnut farming soil has usually acid characteristics. The lime shortage in hazelnut will bring about losses of other nutrients, will turn the leaves yellow and pale before time, weaken the roots, and will create shortege of nitrogen, phosphorus, and potassium in soil.

The physical, chemical and biological properties of soil will be corrected with the calcification of acid soils. The ventilation, heating and water holding properties will also be corrected. Microbial activities in soil increases, and it prevents the decomposition of some nutrients from the soil. Especially the acid soil upgrades the Ph level to normal degrees for the development of hazelnut.

November-December months are generally the most suitable months for liming.This process  has to be repeated in 4-5 years, if necessary in the soil analysis. Two methods of liming are applied in the hazelnut orchards. One of them is to distribute the lime equally to the whole orchard without harming the roots,; and the second method is to distribute the lime carefully and equally around the ring shaped band with 50-60 cm width. 

Farm Fertilizer Application in Hazelnut Gardens at the Age of Efficiency: The farm fertilizers and other organic fertilizers have a positive impact on the increase of soil productivity, retaining of soil nutrients, aerating the soi,l the water holding capacity, and cation exchange capacity.

4 Harvest, Blending, and Storing of Hazelnut

4.1 Harvest

Before starting harvesting, A general cleaning should be made in hazelnut gardens. Hasata baslamadan önce findik bahçelerinde genel bir temizlik yapilmalidir. Onun için hasattan en az 5-10 gün önce bahçenin girinti adi verilen afetle temizliginin iyice yapilmasi gerekmektedir. The harvest maturity of hazelnut is understood by looking at some properties. These are;

• Husks become pale and red.
  
• Hazelnut grains start to move inside 'zuruf's.
• ¾ of hard fruit shells become red and the inner sides take their own tastes and hardness.
  
• When ¾ of the fruits fall from the fruit bearing branches, it shows that the hazelnut has reached its harvest maturity.

The best way to be harvested is by shaking and then collecting the hazelnut, but there aren't many gardens that allow this type of harvest. In the region the most commont harvest type is collecting from the branches with hands.

4.2 Blending

The hazelnuts are  filled in 30-40kg baskets, called harar, selek and hey, or in sacks and are moved to the stackyards. In the region, stackyards are generally flat or a little inclined lands on solid soil.

The hazelnut in the stackyards waits for 3-5 days, then it is spread in a layer with 10-15 cm thickness. In sunny weathers, it is dried 3-5 days by mixing with wood shovel everyday. In this way, the dried hazelnuts are separated from dust, soil and empty parts. After they are cleaned this way, They are spread in the stackyar, and stones, soil and foreign objects are separated.

4.3 Storing

The place for storage should be cool, dry and ventilated. In these conditions, hazelnut can be retained intact for more than 1 year. For a period longer than 1 year, the heat should be 2-4.5 C, and humidity should be between 55-60%. An increase in heat causes a bitter taste, and an increase in humidity causes mold.

5 Hazelnut Diseases

• Xanthomonas campestris pv. corylina (Bacterial blight)

6 Hazelnut Pests

• Hazelnut weevil (Curculio nucum)
• Gypsonoma dealbana (Twig borer)
• Phytoptus avellanae (Big bud mite)
• Xyleborus dispar (Ambrosia beetle)
• Obera linearis (Longhorned beetle or twig borer)
• Mikomya coryli ( Hazelnut gall midge)
• Lepidosaphes ulmi (Apple scale)
• Parthonolecanium corni (Lecanium scale)