The Coffee Tree

Coffee leaves

The leaves of the coffee plant are asymmetrical, sometimes symmetrical, oval-shaped, green in colour with yellow, dark green, bronze or even purple tinges. All leaves have a waxy surface. The distance between leaves is 2,4 to 7 cm.

The edges are slightly wavy and the top and end of the leaf are always pointed. Theleaf protects the plant from frost at night and from intense sunlight during the day. Thecaffeine content is highest in the leaves of the coffee plant.

Coffee tree flower

The flowers are white in colour and star-shaped They are found on the plant in clusters of 8 to 15 flowers, which have a pungent and very pleasant fragrance. After flowering, the fruits of the coffee tree gradually begin to develop - berries. It resembles the jasmine flower in both form and scent. And it is also used for coffee tea.

The fruit of the coffee tree

Small green berries appear when the coffee tree flower is pollinated. After they ripen, they gradually change colour and it is at this point that they remind us of cherries. Inside each berry are two beans with the flat sides facing each other.

In rare cases, a berry may contain only one coffee seed, known as a pea berry. Coffee made from such a bean is called pearl coffee. On average, a single coffee bush produces between 0.5 and 1 kg of coffee beans per year.

A little about the anatomy of the coffee bean

Inside each coffee cherry you will find two seeds, which are protected by several protective layers that must be carefully removed before roasting.

• Theexocarp - the outer green skin that slowly changes colour as it ripens
• Mesocarp - The thin layer of flesh below the exocarp
• Endocarp - The parchment-like pericarp that covers the seed. It hardens during the ripening process to limit the final grain size.
• Spermoderm - Another layer of thin membrane that encases the kernels
• Endosperm - The inner part of the seed. Before roasting it has a beautiful green color

The coffee plant has two stages of growth

The first growth phase of the coffee plant

• A few weeks after sowing, the seed begins to germinate
• After 6 to 8 weeks, the plants are moved to the nursery
• after about one year, they are planted in a plantation

Second growth phase of the coffee plant

• flowering time of the coffee tree ( about once or twice a year, depending on climatic conditions)
• ripening of the berries in about six to eleven months
• after three to five years, the coffee trees planted in the plantation begin to bear fruit and the first, initially smaller, harvest is possible.

What are the species of coffee tree?

Of all the genera and species of coffee trees, Coffea arabica (Arabic coffee tree) and Coffea canephora (Robusta coffee tree)are among the most important. Both species have been bred for a long time to increase fertility, quality and resistance to climatic conditions and various diseases.

Arabic coffee tree

The best coffeesin the world are made from coffee beans. Arabica is the biggest favourite, if only because of its excellent mild flavour and aroma. The Arabica coffee tree produces about 65% of the world's coffee beans. The taste of coffee arabica is characterized by a subtle fruity, acidic note with very little bitterness.

Other commercially grown varieties of Coffea arabica

Coffea arabica has about 600 varieties. Among the best known are:

• Coffea typica, Coffea bourbon - the two most important Arabica varieties
• Coffea mundo novo, Coffea caturra - a cross between Coffea typica and Coffea bourbon, grown in Colombia and Brazil
• Coffea tico, Coffea san ramon - cultivated mainly in Central America
• Coffea blue mountain - the most famous Jamaican variety grown in Kenya
• Coffea mokka - named after the Yemeni port of Mokka
• Coffea murta - grown in places with cooler climates
• Coffea amarella - also known as botucata or amarella, grown in Brazil

Robusta coffee plant

Therobusta coffee plant or Coffee canephora is the second most commonly cultivated coffee plant. According to theUnited Nations'regular yearbook, Coffea canephora accounts for about 30 to 35 percent of world production. However, this share is steadily increasing as better yields are achieved by growing robusta coffee . In addition ,compared to arabica coffee plants, they are less susceptible to various diseases.

However, the Coffea canephora shrub provides beans of lower quality ( bitterness, taste, aroma, higher caffeine content per cup, etc.). Robusta is very popular in France, England and Italy. Robusta is cheaper and is most often used in some proportion with arabica. Robusta coffee varieties are mainly grown in West and Central Africa. They are also found throughout South East Asia and, to a lesser extent, in Brazil under the name Conilon.

Avery well-known variety is the lautense coffee tree. Its berries are burgundy red in colour when ripe. This species is resistant to pests and adverse climatic conditions.

Other Robusta varieties

• Coffea stenophylla - cultivated mainly in Guinea and Sierra Leone
• Coffea cogensis - grows in lowland areas in the Congo. It is characterised by high coffee immunity to coffee rust.
• Coffea liberica, Coffea excelsa - massive trees growing up to 18 metres high. They produce a rich crop, but the coffee from these varieties is bitter tasting with a particular aroma.

Growing and caring for the coffee tree

Coffee trees grow in tropical and subtropical areas of our country. Behind every coffee bean is the painstaking manual work of many people. Growing a coffee tree depends on the quality of the soil, the pH values, the mineral content, the nutrient composition of the soil and the effect of the amount of fertiliser added.

Above all, the optimum temperature is important, whether the coffee plant is grown in the shade or in the sun. Thegrowth of the coffee plant depends on the altitude of the coffee plantation, its location, the amount of sunshine and the system and amount of artificial irrigation.

We must not forget the method of harvesting (manual or mechanised) and the further processing of the coffee beans. When the soil is slightly alkaline, the growth of the coffee plant is retarded. On the other hand, if the soil is too acidic or strongly alkaline, the coffee plant dies.

What actually causes leaf browning in coffee trees?

If the roots of the coffee plant are irrigated for a long time, the leaves gradually turn yellow to brown and eventually die. The coffee tree starts to flower and bear fruit about three years after planting.

From the sixth year onwards, the harvest can be considered abundant. With the right agrotechniques, the bush can take up to thirty years to start fruiting. The fruit takes about 7-9 months to ripen.

The coffee tree is a favourite plant for pests

Thebiggest enemy of the coffee plant is the alien fungus ( Hemileia vastatrix). This fungus attacks the leafy foliage, which then falls off quickly. Another common pest is the Hypothenemus hampei beetle, which attacks both the fruit and the leaves of the coffee tree.

In 1869, this fungus reached Ceylon, where it destroyed all coffee plantations. Caffeine strengthens the plant's defences. It's a kind of poison against insects and mites. It also prevents unwanted seeds from germinating.

Finally, read some interesting facts about the coffee plant

• The growth of the plant and the taste of their coffee beans is affected by altitude, climate, soil type and seed variety.
• A good harvester can pick approximately 50-100 kg of coffee cherries every day.
• Coffee cherries do not all ripen at the same time. Therefore, sometimes several harvests of one plant are needed.
• The average time from flowering to harvest is approximately 9 months.
• Bees feed on the nectar of the flowers and ingest the same caffeine as we do. Everyone just loves coffee!
• Coffee trees generally live 30 to 40 years. However, some can live up to 80 years.
• The plants are pruned once a year to keep them from growing too tall.