Overview of Coffea robusta L. Linden
Coffea robusta L. Linden, commonly known as Robusta coffee, is a species of coffee plant that belongs to the family Rubiaceae. This plant is native to central and western sub-Saharan Africa and is the second most widely grown species of coffee worldwide, after Coffea arabica.
General Appearance
The Coffea robusta plant is a small, evergreen tree or bush that can reach up to 10 meters in height in the wild, but usually grows to about 3 meters in cultivation. It has broad, shiny leaves that are dark green in color and a beautiful bunch of white flowers. The plant produces bright red or purple berries, also known as cherries, which enclose two seeds, which are the coffee beans used for making coffee.
Common Names
In addition to Robusta coffee, Coffea robusta L. Linden is also known by a variety of other common names, including Congo coffee, African coffee, Robusta, Java, Uganda coffee, and Canephora coffee.
Uses
Robusta coffee is highly valued for its caffeine content and is an important crop for countries around the world. This coffee species is typically used in the production of instant coffee, espresso blends, and as a filler in other types of coffee blends. The Robusta coffee species is also known to be more resistant to pests and diseases, which makes it more suitable for cultivation in areas with unfavorable climatic conditions.
The leaves of this coffee species are also used in traditional medicine for treating various ailments such as cough, headache, and fever. It is believed that the leaves contain a number of alkaloids, polyphenols, and other bioactive compounds that give them their therapeutic properties.
Overall, the Coffea robusta L. Linden plant is a valuable and important species of coffee plant that has a wide range of uses and benefits.
Light Conditions
Coffea robusta L. Linden is a shade-loving plant that can grow in both full sun and semi-shaded conditions. However, it thrives best when planted under partial shade or filtered sunlight, as direct sunshine can damage its leaves.
Temperature Requirements
The optimal temperature range for Coffea robusta L. Linden is between 18°C to 25°C. It can tolerate temperatures as low as 13°C and as high as 32°C when grown under the shade. The plant does not fare well under frosty conditions as it can cause severe damage to its leaves and branches.
Soil Requirements
Coffea robusta L. Linden prefers well-draining, moist soil that is rich in organic matter. The soil pH should ideally be between 4.5 to 6.0. The plant requires a depth of at least 1m of topsoil to establish a strong root system. It is also essential to maintain the soil's fertility by adding nutrients such as nitrogen, phosphorous, and potassium, among others.
Cultivation of Coffea robusta L. Linden
The Coffea robusta plant is native to Central and Western Africa and thrives best in hot and humid tropical climates with temperatures ranging from 18 to 29°C. Coffee bushes should be planted in soil that is fertile, well-drained, and has a pH between 4.5 and 6.0. For the best yields, plant coffee bushes in areas with sunlight, shelter from wind, and steady rainfall or access to irrigation.
Watering Needs of Coffea robusta L. Linden
Coffee bushes need adequate water to thrive and produce full yields. They require consistent and regular watering, especially during the dry season. Inadequate watering will lead to reduced yield and lower quality berries. For established bushes, about 40-50 liters of water per bush per week is adequate, but this will depend on the weather and soil conditions.
Fertilization of Coffea robusta L. Linden
Fertilization plays an essential role in promoting healthy growth and increasing yield in Coffea robusta plants. Nitrogen, phosphorus, and potassium are critical nutrients required in adequate amounts, particularly nitrogen. The addition of organic matter such as compost and manure can improve soil fertility. Fertilizers should be applied during or just before the rainy season to ensure optimal nutrient absorption by the plant and reduce nutrient loss from runoff.
Pruning of Coffea robusta L. Linden
Pruning is a necessary practice in Coffea robusta cultivation as it promotes healthy growth, improves yield, and manages plant size. Pruning should be done immediately after harvesting by removing old or diseased branches, suckers, and branches that grow vertically or crossed. This practice enhances better penetration of sunlight, reduces competition for resources, and promotes airflow. It is recommended to leave 5-6 main branches to retain the bush's vigor.
Propagation of Coffea robusta L. Linden
Coffea robusta L. Linden, commonly known as robusta coffee, is propagated by both sexual and asexual methods. Its propagation is essential for the genetic conservation of the plant species and for maintaining its productivity, disease resistance, and quality.
Sexual propagation
The sexual propagation method involves the use of the plant's seeds to grow coffee seedlings. The seeds of Coffea robusta L. Linden are harvested when the berries turn from green to red, approximately six to eight months after flowering. The seeds are then extracted from the berries and dried in the sun. Once the seeds are dry, they can be stored for up to two years without losing viability.
Before sowing, the seeds are soaked in water for 24 hours to soften the seed coat. The seeds are then sown in a nursery bed or in polythene bags filled with a mixture of loam soil and sand. The seeds are covered with a thin layer of soil and kept moist until germination. Germination usually occurs within four to six weeks after sowing.
Asexual propagation
The asexual propagation method involves the use of vegetative parts of the Coffea robusta L. Linden plant. The most common method of asexual propagation for coffee plants is through stem cuttings. Softwood cuttings of the plant are taken from the upper part of the stem during the rainy season. The cuttings should be two to three nodes long, and the leaves on the lower node should be removed. The cuttings are then dipped in a rooting hormone and planted in a rooting medium of sand-filled pots or misting beds. The cuttings are then kept moist and under shade until roots develop, which usually takes three to four months.
Another asexual propagation method is through air layering. In this method, a branch of the Coffea robusta L. Linden plant is wounded and then covered with moist soil or sphagnum moss and a plastic cover. Roots will develop from the wounded area, and once they are well established, the branch can be removed and planted in soil.
Disease and Pest Management for Coffea robusta L. Linden
Coffea robusta L. Linden, commonly known as robusta coffee, is a highly cultivated coffee species for its productivity and resistance to diseases. However, coffee growers still face many challenges in managing pests and diseases that affect the yield and quality of their crops. In this article, we will discuss common diseases and pests of Coffea robusta L. Linden and suggest ways to manage them.
Common Diseases
Coffee Berry Disease (CBD) - CBD is caused by the fungus Colletotrichum kahawae and can severely affect the berry yield of Coffea robusta L. Linden. The infected berries show necrotic lesions, leading to their premature ripening and drop. To manage CBD, farmers should remove infected berries and prune the affected branches. They should also spray the plants with fungicides that contain copper or mancozeb.
Coffee Leaf Rust (CLR) - CLR is a fungal disease that affects the leaves of Coffea robusta L. Linden, causing defoliation and reduced yield. The infected leaves have yellow spots on the upper surface and powdery orange-colored spores on the lower surface. To manage CLR, farmers should remove infected leaves and spray the plants with fungicides that contain copper or triazole.
Common Pests
Coffee Berry Borer (CBB) - CBB is a small beetle that lays its eggs inside the coffee berry, where the larvae feed on the coffee beans. CBB can cause significant damage to the crop, reducing the bean yield and quality. To manage CBB, farmers should use insecticides that contain endosulfan or cypermethrin. They should also implement cultural practices like good hygiene, pruning, and shade management to reduce the pest population.
Antestia Bugs - Antestia bugs are sap-sucking insects that feed on the young berries of Coffea robusta L. Linden, causing their deformation and dropping. The bugs also excrete a substance that affects the coffee's flavor and aroma, making it bitter and unpleasant. To manage Antestia bugs, farmers should prune the affected branches and use insecticides that contain synthetic pyrethroids or carbamates.
In conclusion, managing diseases and pests in Coffea robusta L. Linden is crucial to maintain the crop's productivity and quality. Coffee growers should implement integrated pest management strategies that combine cultural, biological, and chemical practices to control the pest and disease populations.
