Origin
Phaseolus metcalfei Woot. & Standl. is a plant species native to Mexico. It grows naturally in the states of Chiapas, Oaxaca, and Puebla.
Common Names
The plant is commonly known as "Metcalfe's bean," after its discoverer, Harold N. Metcalfe. It is also referred to as "frijol de Metcalfe" in Spanish.
Uses
The seeds of Phaseolus metcalfei are edible and have been used as a food source by indigenous communities in Mexico for centuries. The plant is also used in traditional medicine to treat various ailments, such as gastrointestinal issues, kidney problems, and fever.
More recently, the plant has gained attention from the scientific community due to its high levels of antioxidants and its potential use in crop improvement programs, particularly for the improvement of common bean crops.
General Appearance
Phaseolus metcalfei is a climbing plant that can reach up to 3 meters in height. It has a slender stem and trifoliate leaves that are green in color and can grow up to 10 cm in length. The plant produces small white or pink flowers that give way to elongated pods, each containing 2-4 seeds. The seeds are small, round, and typically have a light brown color.
Light Requirements
Phaseolus metcalfei requires full sunlight, with at least six hours of direct sunlight per day. The plant can survive in areas with partial shade, but optimal growth occurs in full sun.
Temperature Requirements
Phaseolus metcalfei grows best at temperatures between 75-85°F (24-29°C) during the day and 60-70°F (15-21°C) at night. The plant is sensitive to cold temperatures and does not tolerate frost.
Soil Requirements
Phaseolus metcalfei prefers well-draining soils with a pH between 6.0-7.5. The plant can grow in a variety of soil types, but it thrives in sandy loam soils with high organic matter content. The soil should be rich in nitrogen and phosphorus, with moderate levels of potassium.
Cultivation methods for Phaseolus metcalfei Woot. & Standl.
Phaseolus metcalfei Woot. & Standl. is a climber plant that grows well in warm weather. It requires fertile, well-draining soil with a slightly acidic pH between 6.0-6.5. The plant prefers full sun and needs ample support for climbing or spreading. It is important to provide adequate spacing between plants to allow for air circulation to reduce the risk of diseases.
Watering needs for Phaseolus metcalfei Woot. & Standl.
This plant prefers consistent moisture, and it is essential to keep the soil moist but not waterlogged. Proper irrigation is crucial during flowering and pod development. Deep and infrequent watering is recommended to encourage deeper root growth. In hot and dry weather conditions, it may need daily watering, but it is important to avoid watering the leaves and instead focus on the soil.
Fertilization of Phaseolus metcalfei Woot. & Standl.
Applying a balanced fertilizer during soil preparation or early stages of planting promotes healthy growth. A nitrogen-rich fertilizer encourages leaf development, while a phosphorus-rich fertilizer encourages flower and pod development. An organic fertilizer, like compost tea, is suitable for this plant as it promotes soil health and improves nutrient uptake. Regular fertilization is essential, especially during blooming and pod development stages.
Pruning of Phaseolus metcalfei Woot. & Standl.
Pruning of the plant can help promote air circulation, reduce the risk of disease, and improve the quality of the yield. The secondary branches can be trimmed to encourage the primary stems' growth, and this reduces the chances of them breaking under the weight of the pods. It is recommended to pinch off the leaves that are yellow or brown to avoid the spread of diseases. However, avoid excessive pruning, as it can cause stress to the plant, affecting its growth and yield.
Propagation of Phaseolus metcalfei Woot. & Standl.
Phaseolus metcalfei Woot. & Standl. is a plant species that belongs to the family Fabaceae. This plant is commonly known as the Sierra bean and is native to Mexico. The propagation of Phaseolus metcalfei Woot. & Standl. can be done through various methods such as seed propagation, vegetative propagation, and tissue culture.
Seed propagation
Seed propagation is the most common method used to propagate Phaseolus metcalfei Woot. & Standl. This method involves sowing the seeds directly in the field or in a seedbed. The best time to sow the seeds is during the rainy season when the soil is moist. The seeds should be sown at a depth of 2-3 cm and spaced at a distance of 10-15 cm. The seedlings will emerge after 7-10 days.
Vegetative propagation
Vegetative propagation is another method used to propagate Phaseolus metcalfei Woot. & Standl. This method involves taking cuttings from the mother plant and planting them in a suitable growing medium. The cuttings should be taken from healthy, disease-free plants and should be 10-15 cm long. The cut end of the cutting should be treated with a rooting hormone and planted in a growing medium consisting of sand and peat moss. The cuttings should be kept in a shaded area and watered regularly. Rooting will occur after a few weeks.
Tissue culture
Tissue culture is a method used to propagate Phaseolus metcalfei Woot. & Standl. on a large scale. This method involves taking a small piece of tissue from the mother plant and placing it in a nutrient-rich growing medium. The tissue will then develop into a plantlet that can be transplanted into soil. Tissue culture is a complex and expensive method, but it ensures that the propagated plants are disease-free and genetically uniform.
Disease Management
Phaseolus metcalfei Woot. & Standl. is susceptible to various fungal, bacterial, and viral diseases that can negatively impact its yield. Some of the common diseases that affect Phaseolus metcalfei include:
- Anthracnose: A fungal disease that causes lesions on the leaves, stems, and pods of the plant. The infection is usually prevalent during periods of high humidity and warm temperatures.
- Rust: Another fungal disease that appears as yellow or orange pustules on the leaves and stems. Rust is more common in cool and humid conditions and can reduce the plant's overall vigor.
- Mosaic virus: A viral disease that causes mottling and distortion of the leaves. The virus is usually transmitted by infected seeds or aphids and can affect the overall yield of the plant.
To manage these diseases effectively, it is important to follow good cultural practices. These include planting disease-resistant varieties, practicing crop rotation, removing infected plant debris, and avoiding overhead irrigation that can promote fungal growth. Additionally, application of proper fungicides and use of disease-free seeds can also help in controlling the diseases.
Pest Management
Several pests can also damage Phaseolus metcalfei and impact its yield. Some common pests that affect this plant include:
- Bean beetle: A pest that attacks the plant's leaves and stems and can cause significant defoliation if left uncontrolled.
- Spider mites: These tiny insects can cause yellow and white speckling on the leaves of the plant and impact its photosynthesis and overall growth.
- Aphids: Aphids are common sap-sucking insects that can transmit viral diseases and cause stunted growth and deformities in the plant.
To manage these pests, it is critical to implement good cultural practices such as regular inspection, removing the affected plant parts, and using netting to prevent insect attacks. Natural predators can also help in controlling pest populations. Additionally, the use of insecticides can also help manage severe pest infestations.
