Hazelnut Farming

Having produced in Turkey for a long time, Hazelnut is still a conventional export product and contributes greatly in national economy.

Although we are ranked first among countries which produce hazelnut in terms of field, production and export, we are behind the other countries in terms of yield per unit area. Despite it fluctuates from year to year, hazelnut production increases due to the production areas which has been expanding in an uncontrolled manner.

Hazelnut is consumed as a snack as well as has a broad application area in pastry and confectionary industry. Hazelnut has many problems in its production and marketing. The main problem of the production is the yield loss. Hazelnut gardens being old and dense planting, lack of pollinator, deficiencies in technical applications such as pruning, fertilization and fighting are the most important causes resulting in the yield loss. At the top of the marketing problems is the inability to export the hazelnut in the year it is cultivated and accordingly the accumulated stocks year by year.

1. Important Hazelnut Species Cultivated In Turkey

The hazelnut species cultivated in our Turkey is categorized under 3 groups as per their fruit shapes and properties.

2. Climate and Soil Requirements

2.1. Climate Requirements

Hazelnut requires a mild climate to grow well and provide a bountiful harvest. Coastal Zone of Black Sea has the most optimum climate conditions for hazelnut farming. Although it is possible to farm hazelnut in semi-humid and arid climate, lack of necessary rainfall strictly requires irrigation.

In Black Sea Region, it is economically possible to grow hazelnut 60km away the coast towards inland and up to 750m altitude. In regions where annual average temperature is 13-16°C, hazelnut finds its best conditions to grow. Furthermore, in these regions, the lowest temperature must not be less than -8, -10°C, the highest temperature must not be higher than 36-37°C, annual rainfall must be above 700 mm and rainfall must be distributed evenly across months. In addition, the humidity rate in June and July must not decrease below 60%.

2.2 Soil Requirements

Hazelnut is a crop plant with hairy roots, which do not go deeper into the soil, reaching up to 80cm depths of the soil in sloping terrains. While it is not too picky when it comes the soil requirements, it grows best in loamy-vegetal and deep soils rich in nutrition.

3. Hazelnut Farming Method

3.1 Preparation of Terrain and Soil

Having a very long economic life, preparation of land and soil must be done very carefully before planting it. While it is possible to set up a hazelnut garden on the terrains which suit to the cultivation of annual plants, it is also possible to set up a hazelnut garden on the terrains where perennial plants can be cultivated or by renovating the old and aged hazelnut gardens.

3.1.1. Soil-Water Preservation Precautions in Flat Terrains:

For a brand-new hazelnut garden, it is easier to level the soil in flat terrains than sloping terrains, however some different methods are applied depending on the ceiling water being lower or higher.

3.1.2. Soil-Water Preservation Precautions in Sloping Terrains:

In terrains with a slope of more than 5%, a regular planting requires terrain terracing in order to facilitate the storage of rainwaters, prevention of fertilizer wash-out, easier harvest, fertilization and pesticide applications. One of the following terracing systems are used depending on the slope level of the terrain.

• 1. Channel Terraces: When terrain slopes between 5% and 25%
• 2. Trench Terraces: When terrain slopes between 25% and 47%
• 3. Pocket Terraces: When terrain slopes more than %75 and other terrace systems are impossible.

3.1.3. Soil Preparation

Following terrain preparation as above, it is necessary to make a good soil preparation before proceeding to planting. Following applications must be made:

Soil Analysis: After soil preparation, before proceeding to planting, it is strictly necessary to analyze the soil in order for basic fertilization which will provide the soil the nutrients it needs, acidity level of the soil and determination of the lime to be used.
Subsoiling: Means deeply working into the soil. With subsoiling, subsoil got loosen to allow aeration, microorganism activities are increased, water retention capacity also expands, as a result, physical and chemical structure of the soil is relatively rehabilitated.
Remedying Soil Fatigue: If the terrain to be used for hazelnut garden has been used for perennial plants for long years, then it means that a soil fatigue is developed. These soils must be left rest in order to remedy the soil fatigue.

3.2. Selection of Type

In setting up a hazelnut garden, one of the most important issues is the selection of type. The types to be used in the garden

• must be fertile and high quality
• They must be highly sought and high priced ones.
• Type standardization must be observed in the garden.
• Also pollinating types must be planted in the garden in order to ensure a high level of fruit set for main types.

3.3. Selection of Sapling and Preparation to Planting

Hazelnut is a plant which develops stool. These stools are used subject to certain rules. Stools which fit for purpose must have following properties:

• Beds must receive ripe, disease-free, 1-2 aged stools, exposed to sun.
• They must have stools with well developed buds.
• There must be stools which have a good root development and develop at points not closer to the bed.

After selecting stools which have said properties, they must be removed with a hoe without damaging the roots. From these stools, "Pruning to Plant" must be done before proceeding to planting. To do so, inured, bruised and damaged roots must cut away by the point of the healthy tissues, long roots must be shortened. Saplings must be pruned to have a length of 35-40 cm with a sharp shears over an bud without leaving a part in the opposite direction of the bud. So prepared saplings must be planted immediately in the pits which were prepared before.

3.4. Planting and Nurturing Systems

The high time for planting is during autumn. Hazelnut cultivation is generally done according to branch planting system. This system is conventionally used in the hazelnut plantations. There are two widely-used planting systems. These are:

• Vertical Planting System: While this system can be used in the flat terrains, it becomes rather important for the sloping terrains with shallow soil. For sloppy terrains, terracing is applied with a top terrace width of 1.5-2m and inter-terrace clearance of 3.5-5m depending on the sloppiness of the terrain. For flat terrains, the clearance between lines must be 4-5m.
• Branch Planting System: This system which rather fits to flat terrains must be applied after terracing depending on the sloppiness of the terrain for sloping terrains. In this system, planting pits with 120 cm diameter and 60 cm depth must be prepared no later than one month before planting.

3.5. Pruning Method

Starting with the shaping the saplings, pruning is one of the important cultural applications which has positive contributions in ensuring annual stool development until the end of the economic yield period, improving the efficiency an prolonging the economic life. With pruning,

• shaping of saplings and retention of this shape is ensured.
• As a result, many long stools are created every year, achieving abundant and quality products.
• Intertwining of the excessively grown branches is avoided, thereby facilitating the agricultural fight and harvesting
• By removing away the unhealthy, old, dried branches and twigs, including those leaning inside the bed, the beds will have a flat crown.
• Also removal of the foreign trees in the plantation will avoid reduced yields that may occur due to the shading.
• Since hazelnut plant inherently has a higher tendency to create stool, stools must be pruned every year to prevent them from excessively consuming the nutrients.

3.6. Pruning Time

In general pruning is done during Autumn. Pruning must be initiated when vegetation stops and leaves are substantially shed.

The tools used for pruning:

• Pruning Saw
• Pruning Shears
• Gardener's Hoe

3.6.1. Pruning Method in Hazelnut Plantations Shaped As per Nurturing System.

In the first five years, saplings which got their shapes as per nurturing system applied enters in the yield period and this productivity reaches up to maximum level after 12 years. This high level of yield generally continues up to 20-25 ages. During this yield period, dried, broken, injured, unhealthy, intertwined branches as well as all other stools and annual stools which transgressed the shape given, are cut away with a pruning shears every year in Autumn. After 20-25 ages, twigs on the side braches becomes denser and as annual stool length got shortened, the yield starts dropping. In this period where yield starts dropping and physiological balance gets deteriorated, a rarefaction is applied on the annual stools shorter than 10 cm and twigs on the side branches in order to increase the amount of annual stool and length, provided that the shape given is preserved as much as practical. By shortening the stools which overflew into the branch or outside the crown, vegetative and generative development is facilitated. Therefore, annual pruning works are applied progressively denser so that deteriorated physiological balance will be restored.

3.6.2. Pruning Method in Hazelnut Plantations Not Shaped As per Nurturing System.

Plantations show random branching since they are not set up according to planting and nurturing system by using a suitable method. In such plantations, no regular yield is achieved also since no pruning is applied. Such plantations;

• are planted very dense and aged.
• The number of main branches in the bed is excessive.
• Since the clearance between main braches is made very short during planting, it shows branching in just one point, roots develop intertwiningly and branch at height and branches are intertwined.
• Inside the bed are enclosed, so aeration and sunbathing is not sufficient.
• The development of main branches in the bed is irregular and braches have age differences between them and branches and twigs get broken due to the friction between branches during harvest and buds must be emptied.
• Unhealthy, dried, aged branches as well as base stools are cut away at higher levels, since harvesting done with stools left on the main roots for long years, roots has become thick and dysfunctional.

In such gardens, before proceeding to the pruning, some beds must be removed in order to enlarge the clearance between beds. The target must be to reduce the number of main branches in a bed to 6-8 and aged, drying, unhealthy branches and the one of those intertwined branches must be removed with a pruning saw at its bottom and applied with grafting wax at the removed points, while leaving branches developing towards sides untouched. By developing stools in the gaps of beds, the empty sections of the stool are filled and cleaned. Main branches left in the bed untouched are examined one by one and those intertwined, unhealthy, dried and injured branches and twigs are sheared without leaving any parts. All other stools developing into the bed are removed, the stools overflowing the sides excessively are pruned at the top. On side branches, alternating, long and strongly developing stools are left untouched. Weakly developed stools are sheared and rarefied. Thus, with fertilization, efforts are made to restore the deteriorated physiological balance.

If there are thickened roots, "karacakarta" in majority of the main braches, weakened stool development and denudation of branches, then it is very difficult to restore the physiological balance with pruning and fertilization.

3.6.3 Stool Cleaning

Hazelnut has a higher tendency to develop stool. They develop abundantly on the roots of main branches every year. These stools becomes a partner of the nutrients of the bed, causing branches become denser and preventing aeration and sunbathing. On these reasons, by keeping the number of main branch planted fixed during the production, these stools must be cleaned with a gardner's hoe at least two times a year, one being in the autumn and the other at the beginning of June or at the end of May. However, if the dried, broken, unhealthy and aged branches are removed during production time, one of the stools growing in the direction of the branch removed is left untouched to develop. Thus, the place of removed branches in the bed is filled.

3.7. Fertilization

Fertilization is of outmost importance in hazelnut farming in order to have a healthy development of hazelnut saplings following the planting and to have a quality product even after the nurturing period.

3.7.1. Principles of Fertilization:

Achieving the expected benefit from fertilization is only possible with determination of deficient nutrients in the soil and the level of the deficiency. In new gardens or those in the nurturing period, soil and leaf analyses must strictly be carried out in order to determine the nutrients needed by hazelnut to undergo a normal development.

Fertilization in New Hazelnut Gardens (0-5 ages): In order to enrich the soil in organic material, farm manure of 3-5 ton per decare and lime in recommended amounts per soil analysis results must be distributed homogenously all over the land surface and deeply hoed before proceeding to digging the sapling pits. Also, as the basic fertilization, a mix of phosphorus and potassium fertilizers in recommended types and amount must be applied to the sapling pits before planting.

Following this basic fertilization, from first year to fifth year, half of the 40g Nitrogen fertilizer must evenly be applied at the beginning of March and the other half at the end of May or at the beginning of June around the saplings and then hoed. This fertilization applied as such for the first five years will ensure annual growth of stool having the desired properties.

Fertilization of Hazelnut Gardens in the yield period. It is only possible to have a regular development and abundant product yield with the nutrients it receives from the soil. Most important of these nutrients are nitrogen, phosphor and calcium. Although other nutrients are very important for hazelnut, these are not much important as those said above.

Lime Application in Hazelnut Gardens in the yield period: Hazelnut plant can only undergo a normal development and yield abundantly in the soils with a pH of 5-7. However, soils of Black Sea which is used for hazelnut farming is generally acidic in character. The damages to be caused by the lime deficiency in soil on the hazelnut is directly related with characteristics of the soil nature as well as failure of in-taking other nutrients, revealing itself as premature leaf yellowing, dried top stools, weak root formation, and problems observed during nitrogen, phosphor and potassium deficiency.

Application of lime on acidic soils will restore the physical, chemical and biological properties of the soils. Also aeration, heating and water retention capabilities of the soil improve. Micro-organism activities in the soil increases, and decomposition of some nutrients and washing out of some are prevented, and retained in the soil. Especially, soil which is acidic in character also increases its pH to degree which is required for the hazelnut growth.

In general, November-December is suitable period for lime application. Lime application must be repeated if it is found necessary after the soil analysis conducted one in 4-5 years. Lime is applied by using one of two methods. After sprinkling the lime in the recommended amount evenly and regularly all over the garden, it is hoed as much deeper as possible, paying attention not to damage the roots. Or, after distributing it evenly on a strip in the ring form with a width of 50-60cm branch projection of beds, it is hoed as much as deeper possible into soil. In the latter, the lime amount to be applied will be lower than the former one.

Application of Farm Manure in Gardens in the Yield Period: The farm manure or similar organic fertilizers to be introduced in the soil have positive effects such as increased yield levels of soil, retention of the nutrients by the soil, increased levels of water retention and cation exchange capacity, aeration and workability of the soil, early mellowness of the soil.

In hazelnut gardens, these fertilizers are distributed evenly in the amount of 30-40kg on the ring-shaped 50-60 wide strip on the branch projection of the bed at the beginning of Autumn or Spring and then immediately soil is hoed.

4. Harvesting, Threshing and Storage of Hazelnut

4.1. Harvesting

A general cleaning must be done in the hazelnut gardens before proceeding to harvest. To do so, the garden must thoroughly be cleaned with a special tool so-called "girinti" at least 5-10 days prior to harvesting. It is understood that hazelnuts got matured enough to harvest by looking at some indicators. These are;

• Fully reddened husks
• Hazelnut kernels get easily disintegrated from husk.
• 3/4 reddened hard shell, and seeds with its genuine hardness and taste
• 3/4 of the fruits falling down from the branch when you shake the branches carrying the intact and full fruits.

While the best method to harvest hazelnut is the shaking-off & picking-up method, there are few gardens which will allow such method. In this harvesting method, since the hazelnuts are picked up exactly when they are ready to harvest, the highest yield and quality is ensured as well as it protects the buds against damages, which will produce the crop of the next year. The common method in the region is the picking-up directly from the branch. The most important points in this harvesting method are, not to cause friction between branches, plucking off the husks one by one at the point they join with branch, and not to use as a picking up method the "stripping" in order to preserve branches, twigs and buds which will produce the crop of the next year, and carefully putting the branch back after harvesting.

4.2. Threshing

Hazelnuts collected in the baskets are carried in 30-40kg baskets, locally called as harar, selek or hey, or in sacks on back or via transportation vehicles to the threshing site. In the region, the threshing sites are generally flat or slightly sloping meadow and hard earth.

Hazelnuts delivered to threshing site are stored there in piles for 3-5 days. Then they are laid out in a 10-15 thick layer with a rake over the threshing site. In sunny days, the piles are reshuffled with a wooden shovel or rake every day until it dries for 3-5 days. Having dried to some extent, these hazelnuts are introduced into the hazelnut stripping machine to detach their husks. Stripped hazelnuts are laid in a 2-4 cm layer on a cloth for soil sites, without soil for concrete sites. In sunny days, they are allowed to dry by reshuffling them with a rake for 2-3 times very day. Having dried for 3-4 days, hazelnuts are introduced to the ventilator to remove the dust, soil, husk particles as well as hollows. Having cleaned, hazelnuts are again laid out on the threshing site to pick and remove hard and foreign substances such as stone, soil out.

4.3. Storage

The place to be used for storage must be cool, dry and ventilable. In these conditions, hazelnut can be stored intact for a maximum of 1 year. For storage longer than 1 year, temperature must be at 2-4.5C and relative humidity from 55% to 60%. Heightened temperatures causes to rancidity and increased relative humidity causes the mold growth.

5. Hazelnut Diseases

• Hazelnut Bacterial Burn

6. Hazelnut Pests

• Hazelnut Worm
• Hazelnut Moth
• Hazelnut Acarina
• Anisandrus dispar
• Phoma tracheiphila
• Hazelnut Gal Fly
• Lepidosaphes ulmi
• Hazelnut Brown cochineal