Origin
Zanthoxylum gilletii (De Wild.) P.G.Waterman var. cordata G.C.C.Gilbert, commonly known as "Mubilu" or "Mubulu" in Congo, is an evergreen shrub/tree that belongs to the Rutaceae family. This native plant species is widely distributed throughout tropical Africa, including Zambia, Tanzania, and the Democratic Republic of the Congo.
Common Names
Zanthoxylum gilletii has several common names across its native African range, including "Mubulu," "Mubilu," "Mubilua," "Mbilo," "Mbilu," and "Kishanzane." These names are often used interchangeably to refer to the same plant species.
Uses
Zanthoxylum gilletii has various uses in African traditional medicine, where its different parts are used to treat various ailments. The plant's roots and bark are used to treat fever, malaria, dysentery, and stomach pains. Also, the roots and leaves are used in the treatment of rheumatism and are believed to have anti-inflammatory and antipyretic properties. Additionally, the bark, roots, and leaves are used as a diuretic, carminative, and to treat skin diseases and snake bites.
In addition to its medicinal uses, Zanthoxylum gilletii has culinary uses in African cuisine. The fresh and dried leaves are used as a soup ingredient and to flavor meat, fish, and sauces. The fruits are also used to add a tangy, citrus-like flavor to dishes.
General Appearance
Zanthoxylum gilletii is an evergreen tree or shrub that can grow up to 12 meters high. The tree's bark is grayish-brown, and the young branches have numerous sharp thorns. The leaves are glossy dark green and are arranged alternately on the branches. They have a petiole up to 2 centimeters long and are composed of five to nine leaflets. The leaflets are ovate to elliptical, with a pointed apex and a serrated margin. The plant bears small greenish-white flowers that are arranged in axillary inflorescences. The fruit is a small, round, red to black drupe that is usually covered with small tubercles.
Light Requirements
Zanthoxylum gilletii var. cordata grows well in full sunlight, although it can tolerate partial shade. However, shady conditions may lead to reduced growth and poor yield. Therefore, it is recommended to plant the tree in open areas that are not overly shaded by other trees.
Temperature Requirements
The plant is native to East Africa and can tolerate a wide range of temperatures. It starts to grow vigorously at temperatures between 20 and 30 degrees Celsius, and its optimal temperature range is between 25 to 30 degrees Celsius. Temperatures below 15 degrees Celsius may lead to slow growth, while frost can damage the tree and even kill it.
Soil Requirements
Zanthoxylum gilletii var. cordata grows well in a wide range of soils, including sandy, loamy, and clay soils. However, it prefers soils that are well-drained and have a pH of between 5.5 and 7.5. The tree can tolerate soils that are slightly acidic or alkaline, but extreme soil conditions may lead to stunted growth and poor yield.
It is recommended to plant the tree in soils that are rich in organic matter, as this increases nutrient availability and soil moisture retention. Soil preparation should involve loosening the topsoil and adding organic matter such as compost or animal manure.
Cultivation methods
Zanthoxylum gilletii (De Wild.) P.G.Waterman var. cordata G.C.C.Gilbert is a slow-growing plant that needs well-drained soils with a pH of 6.5-7.5. It prefers semi-shade to full sun exposure and thrives in warm to hot climates.
Watering needs
Young plants require regular watering to establish their roots and ensure their growth. Once well-established, Zanthoxylum gilletii (De Wild.) P.G.Waterman var. cordata G.C.C.Gilbert plants can tolerate periodic drought, making them ideal for water-wise gardening practices. Always ensure that the soil is moist and never water during the hottest part of the day as this can scorch the leaves.
Fertilization
Although Zanthoxylum gilletii (De Wild.) P.G.Waterman var. cordata G.C.C.Gilbert is not a heavy feeder, applying a slow-release fertilizer during the growing season can help maintain the plant's health. Alternatively, adding a layer of compost or well-rotted manure around the plant can also provide the necessary nutrients.
Pruning
Zanthoxylum gilletii (De Wild.) P.G.Waterman var. cordata G.C.C.Gilbert requires minimal pruning, mainly to remove damaged, diseased or dead wood. Light pruning can also be done to shape the plant and promote bushy growth. Always use clean, sharp pruning tools and avoid pruning during the dormant season.
Propagation of Zanthoxylum gilletii var. cordata
Zanthoxylum gilletii var. cordata can be propagated by several methods including:
Seed propagation
Seeds can be collected from mature fruits that have turned yellow or red. The seeds need to be cleaned and stored in a dry and cool place before planting. Plant the seeds in a well-draining soil mixture and cover them lightly with soil. Keep the soil moist but not waterlogged and place the container in a warm, partially shaded area. Germination can take up to 3 months.
Root cuttings
Root cuttings can be taken from mature plants during the dormant season. Cut 10-15 cm long root sections and plant them vertically in a well-draining soil mixture. Cover the roots with 2-3 cm of soil and water thoroughly. Keep the cuttings moist and in a partially shaded area until new growth appears.
Air layering
Air layering involves creating a wound on a mature stem and inducing it to produce roots while still attached to the parent plant. To air layer, select a healthy stem and make a wound by removing a thin ring of bark. Apply rooting hormone to the wound and wrap it with moist sphagnum moss and plastic wrap. When roots appear, cut the stem below the layer and pot it in well-draining soil mixture.
Disease and Pest Management for Zanthoxylum gilletii var. cordata
Zanthoxylum gilletii var. cordata, commonly known as the East African Prickly Ash or Mkangazi in Swahili, is a plant that is susceptible to several diseases and pests. Here are some of the common issues that are likely to affect Z. gilletii var. cordata and ways to manage them.
Diseases
The following are some of the common diseases that may affect Zanthoxylum gilletii var. cordata:
Leaf Spot
Leaf spot is one of the most common damages to Z. gilletii var. cordata. It appears as small, dark circular spots on the leaves that gradually increase in size and merge together. The disease can cause the leaves to yellow and drop in severe cases. To manage leaf spot, the infected leaves should be trimmed and destroyed. Fungicides can also be applied to prevent further spread.
Powdery Mildew
Powdery mildew is a fungal disease that usually appears as white or gray, powdery patches on the leaves, stems, and buds of Z. gilletii var. cordata. The disease thrives in conditions of high humidity and temperature. To prevent or control powdery mildew, regular pruning, and adequate spacing of the plants are essential. Fungicides can also be applied to prevent further spread.
Pests
The following are some of the common pests that may affect Zanthoxylum gilletii var. cordata:
Mites
Mites are tiny pests that feed on the leaves and cause discoloration and deformation. Proper and timely irrigation can help prevent their infestation. If infestation already exists, the application of a miticide solution can be done to eradicate them.
Borers
Borers refer to the larvae of certain insects that burrow into the stems, trunks, or branches of Z. gilletii var. cordata. The presence of small piles of sawdust around the plant base may be an indication of their infestation. Some methods to control borers include pruning infested stems and painting them with insecticidal sprays, and releasing parasitic wasps that feed on the larvae of borers.
By effectively managing the pests and diseases that commonly affect Zanthoxylum gilletii var. cordata, the plant can grow and flourish healthily.
