Origin
Brassica parachinensis L. H. Bailey, also known as choysum or choy sum, is a type of Asian green leafy vegetable belonging to the Brassicaceae family. It is believed to have originated in southern China and has been cultivated for centuries in Asia. The plant is now widely grown in many parts of the world, including Southeast Asia, the United States, and Europe.
Common Names
B. parachinensis is commonly known as choysum or choy sum in many Asian countries. In Cantonese, it is called tsai sim, which literally means vegetable heart. In Vietnam, it is called c?i tàu ho?c c?i ng?t, while in Malaysia, it is known as sawi hijau. In the United States, it is often marketed as Chinese flowering cabbage or Chinese flowering kale.
Uses
B. parachinensis is a nutritious vegetable that is consumed in various ways. The shoots, stems, and leaves of the plant are all edible and have a slightly sweet and delicate flavor. It is commonly used in Chinese and Southeast Asian cuisine, where it is stir-fried, sautéed, boiled, or added to soups. The stem is often chopped into small pieces and used in stir-fried dishes, while the leaves are commonly used in soup or cooked with oyster sauce.
General Appearance
B. parachinensis is an annual plant that can grow up to 30-40 cm tall. It has a slender stem with light green leaves that are oblong or oval-shaped, and can grow up to 20 cm long and 10 cm wide. The leaves have a smooth texture and are slightly glossy on the surface. The plant produces small, yellow flowers that bloom in clusters from the tip of the stem, hence its name "flowering cabbage." The flowers are followed by small, oblong-shaped pods containing tiny, black seeds.
Light Requirements
Brassica parachinensis grows best in full sun, which means that it requires at least 6 hours of direct sunlight each day. However, it can also tolerate partial shade, especially in hot climates where full sun can be too intense for the plant.
Temperature Requirements
Brassica parachinensis prefers cooler temperatures and can tolerate mild frosts. The ideal temperature range for this plant is between 15°C to 24°C (59°F to 75°F). The seeds will germinate at as low as 4°C, but seedling growth will be slowed down.
Soil Requirements
This plant grows best in well-drained, fertile soil that is rich in organic matter. The pH level of the soil should be between 6.0 and 7.5. It can tolerate slightly acidic and slightly alkaline soil as long as they are well-drained and adequately fertilized. The soil should be kept moist, and proper watering techniques should be observed to prevent waterlogging.
Cultivation Methods
Brassica parachinensis L. H. Bailey is a fast-growing plant that requires well-drained soil rich in organic matter. It is best grown in a location that receives full sun or partial shade. The plant can be grown from seeds, and it is recommended to start seeds indoors and transplant to the garden when the seedlings are about four to six weeks old.
Watering Needs
The plant requires regular watering, especially during the growing season when the top inch of soil is dry to the touch. Water the plant deeply to ensure that the roots receive enough water, but be careful not to water excessively, as this can cause root rot.
Fertilization
Brassica parachinensis L. H. Bailey benefits from regular fertilization with a balanced fertilizer. Apply the fertilizer every two to three weeks during the growing season to promote healthy growth and development.
Pruning
Pruning is not necessary for Brassica parachinensis L. H. Bailey as it is a compact plant that does not grow very tall. However, it is a good idea to remove any dead or damaged leaves to prevent disease from spreading. The young leaves and stems of the plant are edible, so harvest them regularly to promote new growth.
Propagation of Brassica parachinensis L. H. Bailey
Brassica parachinensis L. H. Bailey, also known as the flowering cabbage, is a plant that is commonly grown for its edible leaves. This plant can be propagated through various methods, including:
Seed propagation
One of the common methods of propagating Brassica parachinensis is using seeds. The seeds can be directly sown into the soil or started indoors in seed trays. It is important to prepare a well-draining soil mix to prevent waterlogging which can cause seed rot. Seeds are usually sown at a depth of approximately 1-2 centimeters and can take 7-10 days to germinate. After the seedlings have developed a few sets of true leaves, they can be transplanted into their permanent growing positions.
Cuttings propagation
Another method of propagating Brassica parachinensis is through stem cuttings. Cuttings should be taken from the parent plant with a sharp and clean tool. Ideally, the cuttings should be taken from semi-woody stems with a minimum height of 10cm. The cut portions of the stem should be dipped into rooting hormone powder and planted in a well-draining soil mix. The soil should be kept moist, and the cuttings protected from extreme heat and direct sunlight. The cuttings can root in about 3-4 weeks and can be transplanted into their permanent growing positions.
Division propagation
Dividing the root clumps of Brassica parachinensis is another method of plant propagation. The plant can be carefully dug out of the ground, and the roots can be carefully separated into several clumps. Each clump should have at least one stem that will produce new leaves. The clumps can be replanted in a new location or potting mix. The soil should be kept moist, and the plants protected from direct sunlight during the initial growth stages.
These propagation methods can provide growers with the means of propagating Brassica parachinensis L. H. Bailey for both commercial and personal use.
Disease Management
Brassica parachinensis L. H. Bailey is susceptible to various diseases that might affect the growth and yield of the plant. The common diseases that affect the Brassica parachinensis L. H. Bailey are:
- Black rot: This disease is caused by a bacterium called Xanthomonas campestris and causes wilting and yellowing of leaves, and blackening of veins. The infected plants might show stunted growth and eventually die. To manage this disease, practice crop rotation, remove the infected plants, use disease-free seeds and plants, and use copper fungicides.
- Clubroot: This disease is caused by a soil-borne fungus called Plasmodiophora brassicae and causes the roots to swell and deform. The infected plants might show stunted growth, yellowing, and wilting of leaves, and eventually die. To manage this disease, practice crop rotation, remove the infected plants, plant resistant varieties, and avoid overwatering the plants.
- Alternaria leaf spot: This disease is caused by a fungus called Alternaria brassicae and causes small spots on the leaves that gradually enlarge and turn brown. The infected plants might show defoliation and reduced yield. To manage this disease, use disease-free seeds and plants, avoid overhead irrigation, and use copper fungicides.
Pest Management
Brassica parachinensis L. H. Bailey is also susceptible to various pests that might affect the growth and yield of the plant. The common pests that affect the Brassica parachinensis L. H. Bailey are:
- Cabbage aphids: These are small, soft-bodied insects that feed on the sap of the plant and cause stunted growth, yellowing, and wilting of leaves. To manage these pests, introduce natural enemies like ladybird beetles, lacewings, and parasitic wasps, use insecticidal soap or neem oil, and practice crop rotation.
- Cabbage loopers: These are green caterpillars that feed on the leaves of the plant and cause skeletonization of the leaves. To manage these pests, introduce natural enemies like parasitic wasps and predatory insects, hand-pick the larvae, use Bacillus thuringiensis (Bt) insecticide, and practice crop rotation.
- Diamondback moths: These are small, grey moths that lay eggs on the leaves of the plant, and the larvae feed on the leaves and cause extensive damage. To manage these pests, introduce natural enemies like parasitic wasps and predatory insects, use Bacillus thuringiensis (Bt) insecticide, and practice crop rotation.
