Overview:
Corylus colurna L. var. colurna, commonly known as Turkish hazel or Constantinople hazel, is a deciduous tree that belongs to the Betulaceae family. It is a fast-growing tree that is widely cultivated for its ornamental value, timber, and edible nuts. The tree is native to southeast Europe and southwest Asia and can grow up to 20-30 meters in height with a trunk diameter of up to one meter.
Appearance:
Turkish hazel has a pyramidal to oval-shaped crown that spreads as the tree matures. The bark is gray-brown and smooth textured when young, but it becomes rough and fissured as the tree ages. The leaves are alternate, simple, ovate-shaped, and are about 6-12 cm long with finely serrated margins. The male flowers of the tree are yellowish-brown hanging catkins, while the female flowers are small and red situated at the tips of the branches. The fruits are edible nuts, enclosed in an involucre that is tubular and toothed.
Uses:
Turkish hazel has many ornamental and practical purposes. It is mainly cultivated for its attractive foliage and unique shape. The tree is also valued for its durable and rot-resistant timber, which is used to make furniture, flooring, and veneers. The edible nuts are consumed fresh or roasted and can be used in various recipes like sweets, desserts, and savories. Traditional medicinal uses of the tree include treatment for coughs, lung diseases, and gastrointestinal disorders. The tree is also sometimes used in landscaping or as a street tree in urban environments.
Cultivation:
The Turkish hazel tree prefers moist, well-drained soils with full sun exposure but can tolerate some shade. The tree can grow in a wide range of climates, from cold to subtropical. It is a tough and resilient tree that can adapt to a variety of growing conditions and needs little maintenance. The tree can be propagated through seed or grafting, and it is relatively disease and pest resistant.
Growth Conditions of Corylus colurna L. var. colurna
Light Requirements: Corylus colurna L. var. colurna is adapted to grow in areas with full sun to partial shade. It prefers bright, well-lit locations and can tolerate up to 5 hours of direct sunlight per day.
Temperature Requirements: This plant species can tolerate a wide range of temperatures, but the optimum range for growth is between 18°C to 26°C. It can withstand extreme temperatures as low as -20°C and high as 40°C.
Soil Requirements: Corylus colurna L. var. colurna grows best in well-drained soils that are rich in nutrients and organic matter. It prefers mildly acidic to neutral soils with a pH range of 6.0 - 7.5. This plant species does not tolerate waterlogged soils and has moderate tolerance for drought stress.
Water Requirements: Adequate moisture is vital for the growth and development of Corylus colurna L. var. colurna. It requires regular watering during the hot and dry season to keep the soil moist but not waterlogged. It is important to avoid over-watering as it can lead to root rot and other fungal diseases.
Fertilizer Requirements: This plant species benefits from occasional fertilization during the growing season. A general-purpose fertilizer with a balanced N-P-K ratio applied at least once in a year can improve plant growth and boost yields.
Cultivation Methods for Corylus colurna L. var. colurna
The Corylus colurna L. var. colurna is a great tree that can be grown in a wide range of soils. It is highly adaptable and grows well in different pH levels, including slightly alkaline and acidic soils, although it prefers well-draining soils. It does best in full sunlight, although it can tolerate partial shade.
The tree requires little maintenance since it is disease resistant and can grow up to 60 feet tall. Therefore, choose a suitable location with enough space to accommodate the plant's mature size. Plant the tree in early spring when the ground is warm enough to encourage root growth.
Watering Needs for Corylus colurna L. var. colurna
Watering Corylus colurna L. var. colurna regularly is vital, especially during dry spells. Newly planted trees need about 1 inch of water weekly during the growing season, which can be reduced after they are established. Deeply and slowly water the tree around the drip line to encourage deep root growth.
Avoid overhead irrigation methods, such as sprinklers, as it can damage the tree's foliage and encourage the spread of diseases. Instead, use a soaker hose or drip irrigation system to water the tree at the base where it is needed.
Fertilization for Corylus colurna L. var. colurna
Fertilizing Corylus colurna L. var. colurna is essential in keeping the plant healthy and robust. Apply a balanced fertilizer with equal parts of nitrogen, phosphorus, and potassium during the growing season, usually from early spring to late summer. Fertilization must be done in small amounts and not exceed the recommended dosage to avoid fertilizer burn.
Additionally, you can add organic matter to the soil to improve its structure and nutrient content. Mulch with organic matter to suppress weed growth, retain soil moisture, and regulate soil temperature.
Pruning for Corylus colurna L. var. colurna
Pruning Corylus colurna L. var. colurna is recommended to maintain its excellent shape and encourage healthy growth. Winter is the best time to prune the tree when it is entirely dormant. Focus on removing any diseased, damaged, or dead branches.
Avoid cutting off more than 20% of the branches during pruning to avoid stressing the tree. Additionally, maintain a single leader since it encourages the tree's upward growth and prevents the development of weak forks.
Propagation of Corylus colurna L. var. colurna
Corylus colurna L. var. colurna, commonly known as Turkish or Persian hazel, is a deciduous tree native to southeast Europe and southwest Asia. It can reach a height of up to 25 meters and has a broad, spreading crown. This plant is usually propagated by seed, but it can also be propagated by cuttings and grafting.
Seed Propagation
Seeds should be collected from mature fruit that has fallen on the ground naturally. The nuts should be separated from the husks and washed with cold water. They should be stratified for three months in slightly damp sand or peat moss at a temperature of 0–5 degrees Celsius. Stratification helps to stimulate the seeds to germinate. After stratification, the seeds can be sown in seedbeds or containers filled with good quality, well-draining soil. The containers should be kept in a shaded area, and the soil should be kept moist but not waterlogged. Seedlings can be transplanted to their permanent location after one year.
Cuttings Propagation
Hardwood cuttings are taken in winter when the plant is dormant. Cuttings should be taken from one-year-old wood that is free of pests and diseases. The cuttings should be about 20-25 cm long, with a diameter of 1 cm. They should be planted in a well-draining rooting medium, and kept in a humid environment. Cuttings can be rooted in a greenhouse or in a protected area outdoors. After rooting, they are transplanted to individual containers, and grown for a year until they are ready to be planted in the desired location.
Grafting Propagation
Grafting is another propagation method for Corylus colurna L. var. colurna. It involves attaching a scion (a twig from the desired tree) to a rootstock of a closely related variety. The graft union should be protected from drying out until the graft is established. Grafted trees may produce fruit sooner than seedlings or cuttings, and they are often used for commercial production.
Disease and Pest Management for Corylus colurna L. var. colurna
Corylus colurna L. var. colurna, also known as the Turkish filbert, is a deciduous tree that can grow up to 25 meters tall. Like any other plant, it is susceptible to diseases and pests that can greatly affect its growth and yield. Here are the most common diseases and pests that may affect Corylus colurna and how to manage them:
Diseases
1. Corylus Bacterial Blight: This is a bacterial disease that is caused by the Pseudomonas syringae pv. syringae bacterium. It affects the leaves, shoots, and nuts of the tree, causing them to develop dark, water-soaked areas that eventually become necrotic. The disease may also cause the tree to produce smaller nuts or none at all.
Management: To reduce the risk of bacterial blight, avoid planting Corylus colurna in areas with poor drainage as the disease thrives in wet conditions. Prune the infected branches or remove the affected parts of the tree. Use copper-based fungicides before the start of the growing season as a preventive measure.
2. Powdery Mildew: This is a fungal disease that affects the foliage, flowers, and nuts of Corylus colurna. It manifests as a white powdery coating on these parts of the tree, causing them to wither and fall off.
Management: Water the trees early in the day so that the foliage dries quickly. Remove the infected parts of the tree and dispose of them properly. Apply sulfur-based fungicides or other fungicides to the tree to prevent the spread of the disease.
Pests
1. Filbert Weevil: This is a beetle that feeds on the developing nuts of Corylus colurna, causing small holes to appear on the shell. The larvae of the weevil feed on the nut kernel and may cause the nut to be deformed or drop prematurely.
Management: Remove any fallen nuts and destroy them to prevent the spread of the weevil larvae. Use insecticides such as carbaryl or pyrethroids to control adult weevils before they lay eggs on the nuts. Apply the insecticides as soon as the flowers start to drop.
2. Eastern Filbert Blight: This is a fungal disease that affects all species of Corylus, including Corylus colurna. It causes cankers to form on the branches, which can eventually girdle and kill them. The disease also affects the nuts, causing them to develop black, sunken spots and become inedible.
Management: Remove any infected branches or parts of the tree and dispose of them properly. Keep the area around the tree clean and free from fallen leaves and nuts. Use resistant varieties of Corylus when planting. Apply fungicides such as copper-based fungicides to control the spread of the disease.
By monitoring the health of your Corylus colurna trees and implementing appropriate preventive measures, you can avoid significant damage from pests and diseases and ensure that your harvest is healthy and abundant.
