Introduction to Growing Olives:
The following information is useful for beginners in Growing Olives.
Olive tree is a subtropical and evergreen tree producing edible fruits known as Olives. The scientific name of the Olive is Olea Europaea. This tree belongs to Oleaceae family. The genus of this tree belongs to Olea. These are popularly found in the Mediterranean basin. We can find them from Portugal to the Levant, the Arabian Peninsula, Asia, China, Canary Island and in the Reunion. In the Mediterranean region, farmers give major importance to Olive as it is a source of Olive oil. The oil, which is extracted from the Olives can be used for culinary purpose as well as for medical purpose. The Olives were first cultivated in the Mediterranean Sea region.
Characteristics of Olives:
Olive tree: The Olive tree reaches up to a height of 8 – 15 m. It is an evergreen tree or shrub, short and squat. The trunk of the tree is twisted and gnarled.
Olive leaves: Leaves of Olive tree are silvery green in color and oblong in shape with a length of 4 – 10 cm and width of 1 – 3 cm.
Olive flower: Tree blooms some flowers with white feathery texture, cleft calyx and corolla.
Olive fruit: The fruit is small in size of about 1- 2.5 cm long, the skin is thin, contains flesh. They are harvested when they are green to purple in color.
Properties of Olives:
The nutritional values that are present in Olives are:
- Energy: 146 kcal
- Carbohydrates: 3.84 kg
- Fat: 15.32 g
- Proteins: 1.03 g
- Vitamins: Vitamin A, vitamin E and Vitamin K
- Minerals: Sodium, Potassium, Calcium, Iron, Magnesium, and Phosphorous
Cultivars/varieties of Olives:
The most popular varieties of Olives are:
- This variety is also known as Sicilian Colossals
- They are large in size
- Dense in nature
- They taste sour
- It is a fleshy pie
- This variety is popularly found in U.S.A
- Kalamata is a Greek variety
- They are plump
- Olives are purple black in colour
- They are good for cooking
- This variety is popularly found in Southern France
- They are small in size
- Brownish purple in colour
- They have a nice flavor, but a bit hard
- They are chewy in texture
Oil – Cured:
- This variety Olives look wrinkled black
- They are meaty with a chewy texture
- They are salty to taste
- This variety of Olive is of two different sub varieties black and green
- Black: This variety is fleshy, soft in texture, sweet to taste
- Green: This variety is mild, but it has vegetal flavour in it
Soil and climate requirements for Growing Olives:
Olive plants are more adapted to soil that is sandy or clayey in nature. The roots of Olive tree are shallow and they don’t penetrate deep into the soil. The pH level, which should be maintained is 5.5 – 8.5. Soils must be well drained for the production of a 3 – 4 feet unstratified structure. They can also survive in poor, low – nutrient soil, but the land should be fertile and capable of being well – drained. The soil should also have good moisture retention capacity.
Olive trees require subtropical climate, but they also do well in mild winter. Plants are sensitive to hard freezing environment. Some varieties grow at a temperature range of 7˚C – 12˚C. Maximum all the Olive varieties can be cultivated below 20˚C. It is better to avoid planting the trees in the frost during late April – mid-may. The crop should not receive rainfall in summer season else it may get damaged.
Land preparation and planting for Growing Olives:
All the unwanted materials like weeds, stones and old cultivated material should be removed from the cropping area. To achieve fine tilth the land must be ploughed many times. Harrowing and levelling should be followed after ploughing of land. On the topsoil well rotten farmyard manure should be applied. In the field proper drainage must be made as it will drain the excess water near the plants.
In certain areas the Olive plants are grown in nurseries and are available for purchase to be farmed in the main area. As soon as the plants are purchased, the transplantation of plants should be done in the main field. To plant the trees, pits should be dug out in the main field and without any damage to root system the plants should be carefully placed. The soil must be pressed firmly after placing the plants. Light irrigation is recommended after planting the plants.
For each variety there is a different plant spacing recommended. The common spacing for all varieties of plants is 0.9 m x 3.7 m and the row gap must be 7 m. The best time for planting Olives is in the spring season (March – May).
Propagation method for Growing Olives:
The Olives are propagated from seeds. In spring season, the Olives should be propagated. As Olive seeds have naturally low viability, so one or the other will geminated if they are planted in multiples. By using nail clippers or bolt cutter the end of the seed should be cracked. The seeds which are cracked should be kept in a bowl with hot water. Soak them overnight to hydrate the embryo and then they become prompt for the germination process. The seed should be spread on the sheet of paper for a few minutes before sowing them. Then they should be sown in 4 inch plastic pots with moist mixture of sand and composed manure. They should be planted with a ¼ inch depth. The pots should be placed in direct sunlight area. After they convert into seedling then they can be transplanted into the main field. There are many ways of propagation, but in general the seed propagation is only used.
Manure and fertilization method in Growing Olives:
By excess use of fertilizers the plants do not respond well. Application of fertilizers should be done moderately. For knowing the required nutrients, soil test should be done, so that we can apply right fertilizers to the soil while preparing it. The manure should be applied to the field after ploughing and levelling. Adequate amount of Nitrogen, Potassium and Phosphorous should be applied in proper ratios and at periodic intervals. After fertilization, a light irrigation should be given. If there is any deficiency of micronutrients, these can be supplied to the land when required.
Irrigation methods in Growing Olives:
These plants have a good response to irrigation. Timely irrigation is believed to increase the fruit size and the total yield from the plants. By sprinklers the irrigation can be supplied. At the time of growing the young plants need more water. Excess rainfall can also harm the tree and the roots of the Olive plants. During summer light irrigation should be supplied frequently, but over – logging of water should be avoided otherwise it will damage the root system of plants. Well drained soil and drainage system in the field should be efficient to control water logging problem. Drip irrigation is most feasble in growing olives.
Read: Drip Irrigation System.
Intercultural methods in Growing Olives:
Weeding: By weeding, unnecessary plants as well as the growth of pest in the field can be controlled. By using pre emergence herbicides the weeds can be destroyed. Manual removal of weeds can also be done.
Pruning: In between the tree or bushes there should be proper air circulation, so the unwanted leaves and stems can be removed to diminish the growth of diseases and pest.
Training: while the Olive tree is in a bush form, it should be trained for trellising over the walls and fencing.
Pest and diseases control measures in Growing Olives:
Olive tree can be affected by some pests and diseases because of factors like weather, location, etc. There should be proper maintenance of Olive plants like irrigation, fertilization, pruning, weeding, mulching, etc. so that these will also encounter the pests and diseases by not affecting the crop. In general the pest and diseases should be handled through their natural enemies. The pest and diseases that affect to Olives plants are:
Nematodes: In case of an attack of nematodes the advice from professionals should be taken to determine and process the fumigation technique.
Olive fruit fly: By destroying the plant which is affected, intensity of Olive fly can be controlled.
Root weevils: By spraying insecticides this pest can be controlled.
Root rot: by the chemicals fumigants intensity of the disease can be controlled.
Wilt: the intensity of wilt can be controlled by regularly cleaning of plant area.
Harvesting techniques in Growing Olives:
The fruit is set when the tree is four or five years old. Olives are harvested from mid – autumn (August) to early winter (November). While harvesting Olives the basic thing is to check and harvest the fully ripe Olives as they can be readily used for cooking or for oil preparation. Olives are harvested manually. These fruits are hand picked. Sometimes, these are also harvested by shaking the tree, but by doing so Olives may get hurt and it may be a loss.
Post harvesting techniques in Growing Olives:
- After harvesting them from the tree the first thing is to clean them thoroughly to remove pesticides, dirt, etc. The stems, twigs and other parts which are attached to Olives should be removed.
- While harvesting the Olives the fully ripe black Olives are considered fresh. They should be plucked carefully from the trees while harvesting. The best quality should be stored naturally at a temperature of 5˚C – 10˚C.
- If we are storing them in a cold storage, then the temperature must be around 0˚C- 2.2˚C. In general, they should not be stored for 2 weeks or more than that as it can harm the skin and internal browning or skin browning may occur.
- The Olives should be packed as per size without any moisture in them. They should be packed in bottles preferably.
- From Olives we can extract, Olive oil, which is used very frequently in cooking. There are many health benefits by using Olive oil.
- Marketing of Olives is done in the local markets and also in the international markets.
Yield of Olives per Tree:
- The yield depends on soil, climate, and cultural practices.
- Yield also depends on cultivars.
- Average yield of Olives per tree is 20 – 30 kg of fruits in a year.
Read: Anjeer Cultivation.