Overview
Macrotyloma chrysanthum (A.Chev.) Verdc. var. occidentalis (Harms) Verdc. is a flowering plant belonging to the family Fabaceae. Also known as Bambara bean, this plant is widely cultivated in Africa as a food crop due to its high protein content. It is also used for medicinal purposes in some African countries.
Origin
The plant is believed to have originated in West Africa, specifically in the region encompassing present-day Mali, Nigeria, and Niger. It has been cultivated for centuries by indigenous communities in the region.
Common Names
The Bambara bean is known by various names in different African languages. In the Bambara language spoken in Mali, it is called "dolique à œil noir" while in Nigeria it is known as "ewa" or "kpa-kpa." Other common names include "Zambia groundnut," "congo goober," and "hog-peanut."
Uses
Bambara beans are primarily grown for their seeds, which are high in protein and nutritionally similar to other legumes like peanuts and soybeans. The seeds can be eaten fresh or dried and stored for later use. They are often boiled or roasted and used in soups, stews, and curries in West African cuisine. Bambara beans are also used in traditional medicine to treat various ailments, including diabetes, hypertension, and kidney diseases.
General Appearance
Macrotyloma chrysanthum (A.Chev.) Verdc. var. occidentalis (Harms) Verdc. is an annual plant that can grow up to 60 cm in height. It has sprawling branches with trifoliate leaves that are green and oblong-shaped. The flowers are yellow, and the pods are round, brown, and contain 2-6 seeds. The seeds are creamy-white with a black patch around the hilum, giving them their distinctive "black-eyed" appearance.
Light Requirements
Macrotyloma chrysanthum var. occidentalis grows best in full sunlight. The plant requires an average of six to eight hours of direct sunlight each day. Inadequate sunlight can affect the plant's vigor and yield. Under low light conditions, the plant may have elongated internodes and sparse foliage.
Temperature Requirements
The plant can grow in a wide range of temperatures, but it thrives in warm temperatures. The ideal temperature range for growing Macrotyloma chrysanthum var. occidentalis is between 20°C and 32°C. The plant is not tolerant of frost and cannot withstand extremely cold temperatures. Frost damage can cause defoliation, dwarfing, or even death of the plant. High temperatures can also have adverse effects on growth and yield, mainly during the flowering and pod filling stages.
Soil Requirements
Macrotyloma chrysanthum var. occidentalis can grow in various types of soils. The plant prefers well-draining soils with a pH range of 6.0 to 7.5. It can tolerate moderately acidic to slightly alkaline soils. The plant requires adequate nutrients for optimal growth and yield. Application of organic matter, nitrogen, phosphorus, and potassium is necessary for good crop productivity. Heavy clay soils may be unsuitable for the plant because they retain too much moisture that can lead to root rot and poor growth.
Cultivation methods
Macrotyloma chrysanthum var. occidentalis thrives in well-drained soils that are high in organic matter. It prefers a warm, humid climate but can tolerate moderate drought conditions. When cultivating this plant, it is best to grow it from seed, which should be planted in spring or early summer after the soil has warmed up. The seeds should be planted about 2.5 cm deep and spaced about 15 cm apart in rows that are about 60 cm apart. This plant can also be propagated from stem cuttings planted in sandy soil under a misting system.
Watering needs
Macrotyloma chrysanthum var. occidentalis requires moderate moisture during the growing season, with an average of 2-3 cm of water per week, depending on the soil type and weather conditions. It is essential to water the plant when the top 2-3 cm of soil becomes dry. However, overwatering should be avoided as it can lead to root rot.
Fertilization
When cultivating Macrotyloma chrysanthum var. occidentalis, it is crucial to apply a balanced fertilizer during the growing season. A slow-release fertilizer, rich in nitrogen, phosphorus, and potassium, should be applied at the beginning of the season, and every four weeks thereafter, following the manufacturer's instructions. Also, it is beneficial to add organic matter to the soil, such as compost or aged manure, before planting.
Pruning
Pruning is not necessary for Macrotyloma chrysanthum var. occidentalis to grow well, but it can help to produce bushier and more compact plants. The best time to prune this plant is immediately after the flowering period, by removing the top 2-3 cm of the stem. This pruning technique encourages the plant to produce lateral branches that will bear more flowers and increase yield. However, if the plant becomes too large and leggy, it can be rejuvenated by cutting back the stem drastically to the ground, leaving only a few centimeters above the soil surface.
Propagation of Macrotyloma chrysanthum var. occidentalis
Macrotyloma chrysanthum var. occidentalis, commonly known as cowpea or black-eyed bean, is a leguminous plant that can be propagated through various methods:
Seed Propagation
The most common method of propagating Macrotyloma chrysanthum var. occidentalis is through seeds. The seeds should be collected from healthy, mature plants and sown in well-draining soil during the start of the rainy season. The seedlings should be thinned out once they reach a height of 10-15 cm, leaving only the healthiest plants.
Cuttings
Cuttings can also be used to propagate Macrotyloma chrysanthum var. occidentalis. Softwood cuttings taken from healthy plants during the growing season should be dipped in rooting hormone and planted in well-draining soil. The cuttings should be watered regularly until they establish roots and begin to grow.
Layering
Layering is another propagation method suitable for Macrotyloma chrysanthum var. occidentalis. This involves bending a healthy, low-hanging branch down to the ground and covering a section of it with soil. The covered section should be kept moist by watering it regularly until roots develop. Once the roots are established, the branch can be cut and transplanted.
Grafting
Grafting is a technique used to propagate Macrotyloma chrysanthum var. occidentalis onto rootstock. This method is useful when propagating specific variations of the plant, or when the soil is unsuitable for optimal plant growth. Grafting involves joining a stem cutting from the desired plant variation onto the roots of a hardier, more vigorous plant.
Propagation of Macrotyloma chrysanthum var. occidentalis is relatively easy and can be done through various means. With proper care and attention, newly propagated plants can grow into healthy, mature specimens in a short period.
Disease and Pest Management for Macrotyloma chrysanthum var. occidentalis
Macrotyloma chrysanthum var. occidentalis is generally a hardy plant with minimal disease and pest issues. However, there are a few common problems that can occur, and early detection and management are key to preventing significant damage.
Common Diseases
Leaf spot: Leaf spot is a fungal disease that causes small, circular, dark lesions on leaves. The spots may eventually merge, causing the leaves to yellow and drop prematurely. To manage this disease, remove and destroy infected leaves, provide adequate spacing between plants to improve air circulation, and ensure proper irrigation to avoid overwatering.
Root rot: Root rot is a soil-borne fungal disease that causes the roots of the plant to rot, resulting in stunted growth, yellowing of leaves, and wilting. This disease is commonly caused by poor drainage, overwatering, or planting in heavy soil. To manage root rot, avoid overwatering, improve soil drainage, and remove and destroy infected plants.
Common Pests
Cutworms: Cutworms are the larvae of various moth species and are common pests in gardens. They cut off young plants at the soil line, causing the plant to wilt and die. To manage cutworms, remove debris and weeds from the garden to eliminate hiding places, apply a biological control such as Bacillus thuringiensis, and protect the base of the plant with a collar made of cardboard or plastic.
Aphids: Aphids are small, soft-bodied insects that feed on the sap of plants, causing leaves to curl and turn yellow. They also excrete a sugary substance called honeydew, which can lead to the growth of black sooty mold. To manage aphids, wash them off the plant with a strong stream of water, introduce natural predators like ladybugs or lacewings, or use insecticidal soap or neem oil as a last resort.
By being vigilant about the early detection and management of diseases and pests, you can help ensure the health and productivity of your Macrotyloma chrysanthum var. occidentalis plants.
