Origin
Glycine wightii (Wight & Arn.) Verdc. var. mearnsii (De Wild.) Verdc., commonly known as Mearns' glycine, is a perennial leguminous plant that belongs to the Fabaceae family. It is native to tropical Africa and has been introduced to Asia and other parts of the world as a forage and pasture crop.
Common Names
Mearns' glycine is known by several other common names, including Ghanaian pumpkin, African pumpkin, and hungry rice.
Uses
Mearns' glycine is primarily used as a forage crop due to its high protein content and palatability to grazing animals. The plant is also known to improve soil fertility through nitrogen fixation, making it a valuable crop in sustainable agriculture. In addition, the leaves and seeds of the plant are edible and are used in African cuisine for their nutty flavor and protein content.
General Appearance
Mearns' glycine is a sprawling herbaceous plant that can grow up to 3 meters in length. It has trifoliate leaves that are oval in shape and are arranged alternately along the stem. The plant produces small purple flowers in clusters, which are followed by seed pods. The seeds are small, round, and brown in color. The plant has a deep root system that enables it to tolerate drought conditions, making it a reliable crop in arid regions.
Light requirements
Glycine wightii var. mearnsii requires full sunlight exposure for optimum growth and development. Under shaded conditions, the plant tends to become leggy and produce fewer flowers and fruits. Therefore, it is recommended to plant this crop in open spaces, where it can receive a minimum of 6 hours of direct sunlight per day.
Temperature requirements
Glycine wightii var. mearnsii is a warm-season crop and thrives in hot and humid conditions. The optimal temperature range for seed germination and growth is between 25 and 35°C. However, the plant can tolerate temperatures as high as 40°C. It is recommended to avoid planting this species during the cold season or frost periods, as it can lead to poor yields and stunted growth.
Soil requirements
Well-drained and fertile soils are best suited for Glycine wightii var. mearnsii cultivation. The plant prefers soils with a pH range of 6.5 to 7.5, which are rich in organic matter and nutrients like nitrogen, phosphorus, and potassium. Sandy loam and loamy soils are suitable for this species, as they offer good drainage and aeration. It is essential to maintain an adequate soil moisture level, as drought stress can affect plant growth and yield negatively.
Cultivation Methods
Glycine wightii (Wight & Arn.) Verdc. var. mearnsii (De Wild.) Verdc. is a perennial plant that grows best in well-draining soil with a pH range of 6.0 to 7.5. It prefers a warm and humid climate and does well under direct sunlight. The plant can be propagated using seeds or stem cuttings.
Watering Needs
The plant requires moderate to regular watering as it prefers moist soil. Water the plant thoroughly but avoid overwatering as it can cause waterlogging. In the winter season, when the plant is dormant, reduce the watering till the soil is slightly damp to touch.
Fertilization
It is recommended to add a slow-release fertilizer or compost to the soil before planting. During the growing season, fertilize the plant every two weeks with a balanced fertilizer. Avoid over-fertilization, which can lead to excessive growth and weak stems.
Pruning
Pruning of the plant should be done in late winter or early spring before new growth occurs. Remove dead or weak stems and thin out any overcrowded areas to improve air circulation. Regular pruning helps to maintain the desired shape and size of the plant and promotes new growth.
Propagation of Glycine wightii var. mearnsii
Glycine wightii var. mearnsii can be propagated through both sexual and asexual methods, each with its pros and cons.
Sexual propagation
The seeds of Glycine wightii var. mearnsii can be collected from mature pods. The seeds are then cleaned and sown in a suitable medium. The optimal time to plant the seeds is during the rainy season in tropical regions. In other areas, seeds can be planted in the early summer or late spring months. The germination rates of these seeds are typically high, and they produce strong, healthy plants.
Asexual propagation
Glycine wightii var. mearnsii can also be propagated through vegetative methods like cuttings. This method can be useful when a plant has desirable traits that an individual might want to replicate. The cuttings are taken from the parent plant and should be about four inches long. The cuttings are then treated with rooting hormones and planted in a suitable medium. It is important to keep the soil moist to aid in rooting. This process will generally take between three to four weeks. Once rooted, the individual plants can be transplanted into their desired location.
Disease Management
Glycine wightii var. mearnsii is susceptible to several fungal diseases, including leaf spot, powdery mildew, and root rot. These diseases are often caused by damp conditions and poor air circulation. To manage fungal diseases, it's important to ensure that the plant is growing in well-draining soil and is not overwatered. Avoid watering from the top to reduce moisture on the leaves. Fungicides can be used as a preventative measure, but should only be used when necessary and according to the instructions.
Pest Management
Glycine wightii var. mearnsii can be affected by several pests, including spider mites, aphids, and thrips. Spider mites and thrips are often indicated by yellow or brown stippling on the leaves, while aphids leave a sticky residue on the leaves. To manage these pests, weekly inspections are recommended to detect any infestations early. Insecticidal soaps or oils can be used to treat mild to moderate infestations, while more severe infestations may require chemical pesticides. It's important to use pesticides according to the instructions and to avoid harming beneficial insects.
