Introduction
Olea europaea L. var. nubica Schweinf. is a subspecies of the olive tree. It belongs to the family Oleaceae and is a small to medium-sized tree that is native to the Nile Valley region of Egypt.
Common Names
The plant is commonly known as the Nubian olive or the Egyptian desert olive. In Egypt, it is called "Zaytoun Nubi" in Arabic.
General Appearance
The Nubian olive tree grows up to a height of 3-5 meters. Its trunk and branches are knotted and crooked, with a grayish-brown bark that is smooth in younger trees and rough in older ones. The leaves are dark green, leathery, and 1-2 cm in length. The flowers are small and white, while the fruits are olives that are small and oval-shaped, with a bitter and acidic taste.
Uses
The Nubian olive tree has been used for a variety of purposes throughout history. The fruits of the tree are used to make oil, which is a staple in Mediterranean cuisine. The oil is also used in traditional medicine to treat various ailments, such as constipation, earaches, and wounds. In addition, the tree is used for shade and ornamental purposes in gardens and parks.
Growth Conditions of Olea europaea L. var. nubica Schweinf.
Olea europaea L. var. nubica Schweinf., also known as Nubian olive, is a subspecies of the Mediterranean olive tree. It is a drought-tolerant tree that can grow up to 6m in height. The following are the typical growth conditions required for the successful growth of Olea europaea L. var. nubica Schweinf.:
Light Requirements
The Nubian olive tree requires plenty of sunlight to grow and produce fruits. It requires at least six hours of direct sunlight per day. It is ideal to plant the Nubian olive tree in an open area where it can receive plenty of sunlight. Lack of sufficient sunlight may result in stunt growth and poor fruit production.
Temperature Requirements
The Nubian olive tree is a hardy tree that can tolerate a wide range of temperatures. However, it grows best in a temperature range of 15-30 degrees Celsius. Temperatures below 10 degrees Celsius may damage the fruit and the leaves while temperatures above 40 degrees Celsius may cause stress to the tree.
Soil Requirements
The Nubian olive tree is adaptable to a wide range of soils, but it prefers well-drained and slightly alkaline soils. It cannot tolerate waterlogged soils as it may lead to root rot and other soil-borne diseases. A soil pH of 6 to 7.5 is ideal for the growth of the Nubian olive tree.
Cultivation Methods
Olea europaea L. var. nubica Schweinf. is commonly grown in a Mediterranean climate, with hot, dry summers, and mild, rainy winters. It is best grown in well-drained soil with exposure to plenty of sunlight. Plant the saplings in the early spring or fall when the soil temperature is about 15°C.
Planting density varies depending on the intended use of the crop. For traditional olive oil production, the recommended planting density is 10-15% less than the densest planting rates used for fruit production. The standard spacing for intensive orchards is usually 5-8 meters between the rows and 2-4 meters between the trees.
Watering Needs
Young plants need regular watering to establish a deep root system and vigorous growth. After the first year, the watering schedule can be reduced. It is important to note that Olives have low water needs and over-irrigation may lead to poor yields and water-logging of the soil. For optimal growth, the plants should receive enough moisture but be allowed to dry out between watering cycles. This helps to promote deep root growth which is critical to the health and survival of the plant.
Fertilization
Fertilization requirements vary depending on soil nutrient status and crop yield targets. Olive trees need nitrogen, phosphorus, potassium, and other micronutrients for optimal growth. It is recommended to have the soil tested so the correct amount of fertilizers can be applied. The timing and amount of fertilizer application will depend on the soil nutrient status and the time of year.
To maintain adequate soil fertility during the active growing season, olive trees should receive fertilizer in several applications. It is recommended to apply nitrogen fertilizer in split applications in the Spring and Fall of the year, although it can also be applied after the olive harvest.
Pruning
Pruning helps to increase the yield, shape the tree, and remove diseased or dead wood. Olive trees benefit from annual pruning or more when needed. Pruning is usually done after the harvest period. The primary goal of pruning is to increase light penetration and air circulation to the interior of the tree canopy.
Clearing the dead and diseased wood, crossing branches, and suckers are some of the primary objectives of olive tree pruning. Also, branches competing for the same vertical space in the tree canopy should be removed or cut back to prevent crowding. Adequate winter pruning will reduce the number of branches needing removal during the summer months.
Propagation of Olea europaea L. var. nubica Schweinf.
Olea europaea L. var. nubica Schweinf. is commonly known as the Nubian olive tree. Propagation of the plant is usually carried out through vegetative and sexual means.
Vegetative Propagation
The vegetative propagation of the Nubian olive tree is done through various methods such as stem cuttings, root cuttings, and suckers. The most common method is stem cutting, where hardwood cuttings are taken from the mother plant in autumn, preferably the outermost and youngest branches. These cuttings are then treated with hormone rooting powder and planted in well-draining soil. Root cuttings can also be taken from healthy roots and planted in soil treated with sand and compost for better growth. Suckers, which are shoots that grow from the ground around the base of the tree, can be dug up and planted in a well-draining soil.
Sexual Propagation
The Nubian olive tree can also be propagated sexually through seed propagation. This method is usually done to produce new cultivars and for breeding purposes. Seeds are collected from fresh ripe fruits, washed thoroughly, and planted in well-draining soil. The seeds should be planted immediately, as they lose viability quickly with time. Seed propagation is usually unreliable, as the seeds may produce plants with different characteristics than the mother plant.
In conclusion, Olea europaea L. var. nubica Schweinf. can be propagated through vegetative and sexual means. Vegetative propagation is the most common and reliable method of propagation that can be used to maintain the characteristics of the mother plant.
Disease and Pest Management for Olea europaea L. var. nubica Schweinf.
Olea europaea L. var. nubica Schweinf. is a subspecies of the olive tree that is native to Egypt, Sudan, and Ethiopia. This plant is widely grown for its olives, which are used to produce oil and for food. However, like any other crop, the olive tree is prone to various diseases and pest attacks that can significantly reduce its quality and yield. Here are some common diseases and pests that may affect Olea europaea L. var. nubica Schweinf. and ways to manage them.
Diseases
Verticillium Wilt - This is a soil-borne fungal disease that causes yellowing and wilting of leaves and can eventually lead to plant death. The best management option for verticillium wilt is to plant tolerant varieties or use resistant rootstocks.
Bacterial Blight - This disease causes leaf and shoot necrosis, cankers, and fruit rot. The best prevention method is to avoid overhead irrigation and to practice good hygiene to prevent the spread of the bacterium. Copper fungicides can also be used to control bacterial blight.
Phytophthora Root Rot - This soil-borne disease causes root rot, leaf wilting, and plant death. To manage phytophthora root rot, avoid overwatering the plant and consider improving soil drainage. Fungicides and soil amendments can also be used to control the disease.
Pests
Olive Fruit Fly - This is the most destructive pest of the olive tree as it causes significant damage to the fruit. The fly lays eggs inside the olive, which then causes the fruit to rot. To control olive fruit fly, use pheromone traps to monitor and a spray regime of GF-120 every 15-20 days.
Olive Psyllid - This pest damages the leaves and causes defoliation, which can lead to reduced fruit production. The best management option for olive psyllid is to use registered insecticides.
Olive Lace Bug - This insect causes silvering of leaves and defoliation. To control olive lace bug, use insecticides and prune the plant to improve air circulation.
Overall, disease and pest management are essential for the health and productivity of Olea europaea L. var. nubica Schweinf. plantation. Growers should monitor their plants regularly, keep them well-maintained, and use appropriate control measures when necessary to prevent and manage diseases and pest attacks.
