Overview
Phaseolus angustissimus Gray, commonly known as the tapered bean, is a species of plant in the family Fabaceae, which is native to North America. It belongs to the subgenus Phaseolus and is closely related to the common bean, Phaseolus vulgaris. The plant is an annual herb that is valued for its edible and medicinal properties.
Appearance
The tapered bean plant is a climbing or trailing vine that can grow up to 5 feet tall. It has a slender stem that is covered with small hairs. The leaves are trifoliate, and each leaflet is oblong-elliptic, 2.5-4 cm long, and 1.5-2 cm wide. The flowers are white, pink, or purplish in color, and they are borne on long peduncles. The pods are linear to oblong, 10-25 cm long, and about 1 cm wide. The seeds are oval, flattened, and light brown in color with dark mottling.
Uses
Phaseolus angustissimus is primarily cultivated for its beans, which are a good source of protein, dietary fiber, vitamins, and minerals. The plant is also used in traditional medicine to treat a wide range of ailments, including diarrhea, fever, kidney problems, and respiratory infections. In addition, the tapered bean plant is used as a cover crop to control erosion and improve soil fertility.
Common Names
Phaseolus angustissimus is known by several common names, including the tapered bean, Rio Grande bean, narrowleaf bean, and San Felipe bean. In Spanish, it is called frijolillo, frijol pequeño, or frijol de San Felipe.
Light Requirements
Phaseolus angustissimus Gray typically requires full sun to thrive, although it can tolerate partial shade in some cases. Plants that receive less than six hours of sunlight per day may produce fewer flowers and fruits, and may also be more susceptible to diseases and pests.
Temperature Requirements
This plant prefers warm temperatures and cannot tolerate frost. The optimal temperature range for growth is between 60-80°F (15-27°C). Seedlings should be kept at slightly warmer temperatures (70-85°F or 21-29°C) until they develop their first true leaves.
Soil Requirements
The soil for Phaseolus angustissimus should be well-draining, with a pH between 6 and 7.5. Good soil structure is important for root development and water uptake. The addition of organic matter such as compost or aged manure can improve soil quality and fertility. This plant can tolerate a range of soil types, including sandy, loamy, and clay soils.
Cultivation Methods
Phaseolus angustissimus Gray is a legume that typically grows in desert regions, and it is well-adapted to the arid climate. The plant requires warm temperatures between 25-30 degrees Celsius to grow successfully. To cultivate the plant, start by selecting the right location with well-drained soil that is rich in organic matter. Plant the seeds in rows, leaving a distance of at least 20-25 cm between each row. The seeds should be planted at a depth of 2-3 cm and watered gently. The germination period will take about 7-10 days.
Watering Needs
Phaseolus angustissimus Gray requires moderate to low watering. Overly moist soils can cause the plant to decay or experience root rot. It is essential to water the plant sparsely, but regularly, depending on the humidity of the environment. Drip irrigation is highly recommended to minimize accidents and avoid leaving water spots on the leaves. The water requirement for this plant is between 300-400 ml per week, depending on the season and the soil's moisture content.
Fertilization
Fertilizers play a vital role in the growth and fertility of Phaseolus angustissimus Gray. The plant requires nitrogen, potassium, and phosphorus in varying quantities. Use a slow-release nitrogen fertilizer consisting of ammonium sulfate, urea, or ammonium nitrate to achieve optimal yields. Add the fertilizer before planting or during the crop's germination phase. Organic fertilizers such as cow dung or composted organic material can also be used to increase the soil's overall fertility.
Pruning
Pruning the Phaseolus angustissimus Gray plant is not necessary, but it is beneficial to ensure that the plant remains strong and healthy. Pinch off the tips of the young plant's shoots to encourage the development of new branches and stems. Remove the dead, damaged, or decaying leaves from the plant as they can create a breeding ground for pests and diseases. Prune the straggly or overgrown stems to promote healthy growth and improve the overall look of the plant.
Propagation of Phaseolus angustissimus Gray
Phaseolus angustissimus Gray, also known as the Arizona bean, is a plant of the family Leguminosae. It is a perennial vine, originally found in the Sonoran Desert of Arizona, USA, and northern Mexico.
Propagation of Phaseolus angustissimus Gray can be done through two methods: seed propagation and vegetative propagation.
Seed Propagation
Seed propagation is the easiest and most common method of propagating the Arizona bean. To do this, you need to collect the ripe seed pods from the plant when they are mature. The pods are flat, long, and slightly curved. They contain about six to eight brown-to-black colored seeds.
Once you've collected the pods, you need to dry them in a warm, dark place until the seeds are loose in the pod. Afterward, the seeds can be stored in a cool, dry place until you're ready to plant them.
When planting, soak the seeds overnight in water to encourage germination. Afterward, you can plant them in well-draining soil, making sure they're about 1 inch (2.5 cm) deep. Keep the soil moist but not waterlogged and place them in a warm, sunny location. Germination typically takes about two weeks.
Vegetative Propagation
Vegetative propagation involves cloning the Arizona bean plant by cutting a piece of stem or leaf and planting it in a rooting compound or soil. While this method is less common than seed propagation, it can be useful if you want to propagate an exact copy of a desirable plant or if you have limited seeds.
To do this, cut a 6-inch (15 cm) piece of stem from the parent plant just below a node. Remove all but the top two to three leaves, dip the cut end in rooting hormone, and plant it in a moist rooting medium or well-draining soil. Keep the plant in a warm, humid location and water it regularly. Once roots have formed, you can transplant the new plant to a larger container or garden bed.
Propagation of Phaseolus angustissimus Gray can be done using either seed propagation or vegetative propagation. Choose the method that's best for your needs and environment. With proper care, your new plants will grow to maturity and produce pods full of seeds for future propagation.
Disease and Pest Management for Phaseolus Angustissimus Gray
Phaseolus angustissimus Gray, commonly known as Texas kidney bean, is susceptible to various pests and diseases. Here are some common diseases and pests that might affect the plant and suggested management strategies:
Diseases:
Anthracnose: This disease causes circular, sunken lesions on the leaves, stems, and pods resulting in reduced yields. To manage this disease, maintain good field sanitation by removing infected plant debris and using resistant cultivars. Also, apply fungicides such as chlorothalonil or azoxystrobin at the first sign of infection.
Rust: Rust disease causes small, yellowish specks on the underside of the leaves which develop into red-orange pustules. It leads to defoliation resulting in reduced plant vigor. To manage rust disease, apply a suitable fungicide like tebuconazole and avoid planting in areas with a history of rust infection. Also, cultivate resistant cultivars.
Bean Common Mosaic Virus: BCMV is a viral disease that leads to mosaic symptoms on the leaves, yellowing, and stunted growth. To manage this disease, use certified disease-free seeds, and remove infected plants as soon as they are noticed. Also, control aphid populations, which transmit the virus, with insecticide sprays or natural predators like ladybugs.
Pests:
Cutworms: Cutworms feed on the stems of young seedlings leading to wilting and eventual death. To manage cutworm infestation, avoid planting near grassy areas as they provide ideal habitats for cutworms. Use baits or traps to reduce cutworm populations, or use insecticides to control severe infestations.
Leafhoppers: Leafhoppers feed on the sap of the plant leading to yellowing of the leaves and stunted growth. To manage leafhoppers, use insecticidal soap or neem-based products. Also, avoid excessive nitrogen application as it results in tender growth, which is susceptible to leafhopper feeding.
Whiteflies: Whiteflies feed on the undersides of the leaves causing yellowing and stunted growth. To manage whitefly populations, use insecticidal soap sprays or sticky traps. Also, remove weeds and infected plants, which serve as ideal habitats for whiteflies.
By implementing the above management strategies, it is possible to prevent or minimize the damage caused by these pests and diseases, thus ensuring higher yield and plant growth.
