Hazelnut
Several subspecies exist
(Corylus cornuta, Corylus avellana, Corylus americana, …)
(Corylus cornuta, Corylus avellana, Corylus americana, …)
History
Hazelnut trees have a very ancient origin since their appearance dates back to the Tertiary (Oligocene). In the Upper Tertiary (Miocene), there were already two very distinct types of hazelnut: one with a narrow leaf (Corylus insignis Herr), the other with a broad leaf (CORYLUS Mac-Quarry Herr), ancestor of the common hazel Corylus avellana L., which was the dominant plant species in Europe between 7500 and 5000 BC. At present, there are about fifteen species or subspecies, half of which are of more or less cultural interest.
Origins
These species form the genus Corylus L., which belongs to the order Fagales, family Betulaceae, tribe Corylea.
All of these species are diploid with 2 n = 2 x = 22 chromosomes. A few triploid (33 chromosomes) or aneuploid (23 chromosomes) individuals have been found in the species Corylus avellana L.
All of these species are diploid with 2 n = 2 x = 22 chromosomes. A few triploid (33 chromosomes) or aneuploid (23 chromosomes) individuals have been found in the species Corylus avellana L.
Orchard Management
The success of the cultivation of the orchard is based on several essential points:
- Choice of site: Prefer a sunny location.
- Soil type: The hazelnut tree likes rich, well-drained and amended soil (e.g. with compost), to ensure good nutrition and avoid waterlogging.
- Planting time: Fall is usually ideal for establishment, as it allows young trees to establish before the spring restart.
Density and spacing: Proper spacing promotes ventilation and limits excessive moisture, reducing the risk of disease. All while promoting a good disposition of pollinators.
Physiology
The Hazelnut differs greatly in its height and format, to each species check it. Its physiological characteristics include:
- Flowering: A need for a cold period to break dormancy of the male and female buds. Also of a great variability of emergence according to genotypes.
- Growth: The tree has good growth and develops dense branching in height.
- Fruit: Fruit setting is quick!
Tree Management
Good management of the Hazelnut tree requires :
- Training pruning: The objective of this pruning will be to create skylights and/or revive the annual shoot in order to ensure a balance between fruiting and vegetative growth.
- Maintenance pruning: This is only justified in two situations, when the stand becomes too dense and solar radiation no longer penetrates between the trees.
Fruit Quality
Hazelnuts are distinguished by:
- Appearance: When the entire fruit has turned brown and the base of the involucre changes colour.
- Taste and aroma: They have a dense flesh, when it fills the entire shell it reaches its maximum taste. Do not wait for the nut to detach from the involucre.
- Nutritional value: High energy power (600-680 kcal per 100 g).
Plant Protection
To preserve health, several practices are recommended:
- Regular monitoring: Careful monitoring allows you to quickly identify pest attacks (such as aphids) or the appearance of diseases.
- Preventive treatments: The use of biological treatments (nettle manure, horsetail manure) can strengthen the tree’s natural defences.
- Cultural interventions: Regular pruning to remove diseased wood, removal of fruit that has remained on the tree or fallen to the ground, and mulching the soil help to limit moisture and the risk of infection.
Harvest
The hazelnuts are harvested in summer, as soon as the fruits have reached their optimal ripeness:
- Timing: It is essential to let the fruit ripen on the tree in order to have an organoleptic quality.
- Harvesting methods: In professional and private orchards, the nut is still picked manually.
- Post-harvest storage: Nuts are stored after being stripped of their involucre and left to dry for a long time.
