Overview
Cucumis sativus L. var. usambarensis A.Zimm. is a plant species that is widely known for its edible fruits also called cucumbers. This plant has various common names such as African cucumber, African horned cucumber, and jelly melon. It is a climbing vine that requires trellising or support to grow up and develop properly.
Origin
Cucumis sativus L. var. usambarensis A.Zimm. is indigenous to several parts of sub-tropical Africa including Angola, Burundi, Democratic Republic of Congo, Kenya, Mozambique, Rwanda, Tanzania, and Uganda. The plant’s popularity has since spread worldwide, becoming one of the most commonly cultivated vegetables across the world.
Description
The plant’s fruits are characterized by their oblong shape, measuring up to 30 centimeters in length when ripe. The fruit's skin is yellow-orange in color, with rigid spikes that make handling the fruit challenging. The fruit's interior is divided into chambers containing a translucent jelly-like pulp with many small green seeds. The plant prefers to grow in warm temperatures, with a high concentration of rainfall. This plant is predominantly used for its fruit, which can be eaten raw, pickled, or cooked.
Uses
Cucumis sativus L. var. usambarensis A.Zimm. has various uses. Its fruits have some medicinal value, being rich in vitamins C and B, minerals, and antioxidants. The fruit juice is used as a skin moisturizer, sunburn, and insect bite cure. The fruit is also used in food, especially salads, sandwiches, and pickling. Additionally, the fruit pulp is used to make jelly and beverages. The plant is also used as an ornamental plant because of its unique and intriguing appearance.
Light Conditions
Cucumis sativus L. var. usambarensis A.Zimm. requires plenty of sunlight. Therefore, it is best to place the plant in an area with full sun exposure. If possible, it should be exposed to sunlight for at least 6 hours a day. The lack of sufficient sunlight can lead to stunted growth and low yields.
Temperature Requirements
The ideal temperature for the growth of Cucumis sativus L. var. usambarensis A.Zimm. ranges between 18°C and 30°C. However, it can still grow in temperatures as low as 10°C, but it may lead to delayed growth and low yields. On the other hand, temperatures higher than 35°C can result in a dehydrated plant and poor fruit development.
Soil Requirements
The soil for planting Cucumis sativus L. var. usambarensis A.Zimm. should be well-drained and rich in organic matter. The ideal pH value is between 6.0 and 7.0. The plant can grow in various types of soil, including sandy, loamy, and clay soils. However, it is essential to maintain consistent moisture levels in the soil to promote healthy growth.
Cultivation of Cucumis sativus L. var. usambarensis A.Zimm.
Cucumis sativus L. var. usambarensis A.Zimm., commonly known as African horned cucumber or kiwano, is a vine plant native to Sub-Saharan Africa. It thrives in warm climates and can be grown year-round in tropical regions.
The plant requires a well-draining, nutrient-rich soil with a pH range of 6.0 to 7.5. It can be propagated from seeds or cuttings, and the best time for planting is during the wet season.
It is recommended to space the plants at least 30cm apart to allow for proper growth and support. The vines can spread up to 3 meters, and trellising or staking may be required to support the weight of the fruits.
Watering Needs
Cucumis sativus L. var. usambarensis A.Zimm. requires consistent and adequate watering, especially during hot and dry periods. It is best to water the plants in the morning to avoid fungal growth and disease.
The water should be applied directly to the soil, avoiding wetting the foliage as it can lead to leaf spot diseases. The plants require 2-4cm of water per week and may require more during fruiting. Overwatering should also be avoided to prevent root rot.
Fertilization
The plant requires regular fertilization to promote healthy growth and fruit production. A balanced fertilizer with a 10-10-10 NPK ratio can be applied every 3-4 weeks during the growing season.
Organic fertilizers such as compost or well-rotted manure can also be incorporated into the soil before planting. It is essential to follow the manufacturer's instructions for application rates and frequency to prevent fertilizer burn.
Pruning
Pruning is an essential practice to promote fruit production and prevent the plants from becoming too dense. It is best to prune the plants early in the season to encourage lateral growth.
Remove any leaves or stems that show signs of disease or pest infestation. The lateral shoots can be pruned to allow for adequate light and air circulation. It is also best to remove any fruits that show signs of deformity or damage to avoid spreading disease.
Pruning should be done carefully to avoid damaging the vines or exposing the plant to sunlight, which can lead to sunscald. The pruning shears should be disinfected regularly to prevent the spread of disease.
Propagation of Cucumis sativus L. var. usambarensis A.Zimm.
Cucumis sativus L. var. usambarensis A.Zimm. is commonly known as the African cucumber, and it belongs to the family Cucurbitaceae. This plant can be propagated through various methods, including:
Seed Propagation
The most common method of propagation for Cucumis sativus L. var. usambarensis A.Zimm. is by using its seeds. The seeds are sown directly into the soil or into seed trays. In both cases, the soil should be moist, and the seeds should be covered lightly with soil. When the plant reaches the two-leaf stage, it can be transplanted to its permanent location.
Vegetative Propagation
Cucumis sativus L. var. usambarensis A.Zimm. can also be propagated through vegetative methods. This method involves taking cuttings from the parent plant and rooting them. The cuttings are taken from the stem just below a node and should be about 10-15cm in length. These cuttings are then planted in a rooting medium, such as sand or vermiculite until they develop roots. Once roots have formed, the rooted cutting can be transplanted to its permanent location.
Grafting
Grafting is another method of propagation for Cucumis sativus L. var. usambarensis A.Zimm. In this method, the scion (the top part of the plant) is grafted onto the rootstock of another Cucumis sativus L. var. usambarensis A.Zimm. plant. This method is beneficial because it allows growers to use the specific characteristics of the rootstock to improve plant growth.
Overall, Cucumis sativus L. var. usambarensis A.Zimm. can be propagated through a variety of methods, including seed propagation, vegetative propagation, and grafting. Each method has its advantages and disadvantages, and growers should choose the method that best suits their needs and environment.
Disease Management for Cucumis sativus L. var. usambarensis A.Zimm.
Cucumber is susceptible to a variety of diseases which can cause significant damage to the plant. The common diseases that affect this plant are downy mildew, powdery mildew, bacterial wilt, and mosaic viruses. Effective management of these diseases involves cultural practices, use of resistant cultivars, and chemical control.
1. Cultural Practices: Cultural practices include crop rotation, sanitation, and use of clean seeds. Crop rotation with non-host plants breaks the disease cycle and reduces the inoculum levels on the field. Sanitation practices like removing infected plant debris can reduce the source of infection. Using clean seeds, either commercially or harvesting from disease-free plants, helps in reducing the initial inoculum levels of the disease.
2. Use of Resistant Cultivars: Growing resistant cucumber cultivars is a cost-effective way of managing diseases. Several cucumber varieties are resistant to powdery mildew, downy mildew, and root knot nematodes.
3. Chemical Control: Fungicides and bactericides are effective in managing diseases like downy mildew, powdery mildew, and bacterial wilt. However, their use should be integrated with cultural practices to achieve optimal control. Fungicides like copper-based products, mancozeb, and chlorothalonil are effective against downy mildew. For powdery mildew, fungicides like myclobutanil, trifloxystrobin, and cyprodinil can be used. Bacterial wilt can be managed with a combination of copper-based products and antibiotics like streptomycin.
Pest Management for Cucumis sativus L. var. usambarensis A.Zimm.
Cucumber is also susceptible to a variety of pests that can cause significant damage to the plant. The common pests that affect this plant are aphids, spider mites, cucumber beetles, and whiteflies. Effective management of these pests involves cultural practices, use of resistant cultivars, and chemical control.
1. Cultural Practices: Cultural practices such as crop rotation, companion planting, and use of reflective mulch can deter cucumber pests. Crop rotation with non-host plants helps break the pest cycle and reduce pest numbers. Companion planting with plants like marigold, radish, and nasturtium helps in repelling pests. Reflective mulch like aluminum-coated plastic reflects light that disorients aphids and whiteflies.
2. Use of Resistant Cultivars: Resistant cucumber cultivars like Marketmore 76 and Dasher II have shown resistance to cucumber beetle damage. Using resistant cultivars reduces the need for chemical control.
3. Chemical Control: Insecticides and acaricides are effective in managing cucumber pests. However, their use should be integrated with cultural practices to achieve optimal control. For aphids, insecticides like imidacloprid, thiamethoxam, and acetamiprid can be used. Spider mites can be controlled with acaricides like spiromesifen, abamectin, and hexythiazox. Cucumber beetles can be managed with insecticides like carbaryl, pyrethroids, and neonicotinoids.
