Overview:
Rorippa nasturtium-aquaticum (L.) Hayek, also known as Watercress, belongs to the family Brassicaceae and is a perennial aquatic plant. It is popularly known for its culinary, medicinal and ornamental uses.
Origin:
Watercress is a native of Europe and Asia and was later introduced to the Americas, Africa, and Australia. It can usually be found near slow-moving or stagnant water bodies, such as streams, springs, and shallow ponds.
Appearance:
The plant usually grows up to a height of 80cm and has alternate, compound leaves, and small white flowers that bloom in the summer. It is a semi-aquatic plant that looks similar to cresses, but its leaves are rounder and lack the distinctive or pungent aroma of cresses.
Common names:
Watercress is known by various names such as Nasturtium officinale, Rorippa nasturtium-aquaticum, Yellowcress, Brown Cress, Watercresses, and many others.
Uses:
Watercress is a versatile plant used widely in different areas. As a culinary herb, its leaves and stems add a unique peppery, tangy flavor to soups, salads, and dressings. The plant is highly nutritious, low in calories, and high in Vitamins A, C, and K. It also has mild analgesic, anesthetic, and expectorant properties that aid in the treatment of, among others, colds, coughs, bronchitis, arthritis, and urinary problems. As an ornamental plant, watercress is commonly grown in water gardens or aquariums and is a beautiful addition to any aquatic ecosystem.
Light Requirements
Rorippa nasturtium-aquaticum, also known as watercress, requires a significant amount of sunlight to grow and thrive. Ideally, it should be placed in an area that gets at least six hours of direct sunlight a day, although it can tolerate partial shade in warmer climates. Lack of adequate sunlight can hamper its growth and result in stunted plants.
Temperature Requirements
Rorippa nasturtium-aquaticum is a cool-season vegetable that prefers temperatures between 60-65°F. It is not tolerant of high temperatures and can wilt or bolt when exposed to prolonged periods of heat. Therefore, it is best to grow it in cooler seasons or in an area with mild temperatures throughout the year.
Soil Requirements
The ideal soil for Rorippa nasturtium-aquaticum is moist, well-drained, and rich in nutrients. It is a semi-aquatic plant and requires plenty of water to thrive. Therefore, the soil should be able to retain moisture while also being well-draining to prevent waterlogging. A soil pH of 6.0-7.5 is ideal for the plant's growth and development.
Cultivation Methods
Rorippa nasturtium-aquaticum, commonly known as Watercress, is a semi-aquatic plant that thrives in damp soil and shallow water. It prefers cool temperatures to hotter ones. To cultivate watercress, you need to select a moist area that receives sufficient sunlight and provides good drainage. You can grow watercress in pots or plant beds. When planting in a pot, ensure that the pot has at least four drainage holes for proper water drainage.
Watering Needs
Watercress requires consistent moisture levels in the soil or water to thrive. Water the plant frequently enough to keep the soil or water damp but not soggy. Ensure that the soil or water does not dry out, particularly during hot weather conditions. When growing in pots, ensure that excess water drains out of the drainage holes to prevent waterlogging in the soil.
Fertilization
Watercress requires a good source of nutrients to grow healthily and produce quality foliage. Fertilize the plant with nutrient-rich organic or inorganic fertilizers every two or three weeks. You can use compost, liquid fertilizers, or slow-release fertilizers when planting in soil. In contrast, you can use nitrogenous liquid fertilizers when planting in water.
Pruning
Pruning is essential to keep watercress healthy and promote a steady growth pattern. Prune regularly to control the plant size, remove dead or yellow leaves, and encourage the emergence of fresh foliage. Use a pair of sterilized garden shears or scissors to cut back the plant. Do not cut the foliage too short as this can weaken the plant.
Propagation of Rorippa Nasturtium-aquaticum
Rorippa nasturtium-aquaticum, also known as Watercress, can be propagated via different methods such as seed propagation, vegetative propagation, and hydroponics.
Seed Propagation
Seed propagation is the most common method used to propagate Rorippa nasturtium-aquaticum and can be done either indoors or outdoors. The seeds can be directly sowed into soil or in trays and propagated indoors before being transplanted outdoors.
The best time to sow the seeds is during early spring or late fall, and the seeds take approximately 10 to 14 days to germinate.
Vegetative Propagation
Vegetative propagation of Rorippa nasturtium-aquaticum can be done through stem cuttings or root division. Stem cuttings should be taken during the active growth period and should have at least two nodes and a few leaves. These cuttings can then be rooted in a rooting hormone and placed in soil or water.
Root division is another method of vegetative propagation which involves dividing the plant at the root level. This method works best when the plant is already overgrown or when the roots are beginning to show at the soil surface. The separated sections can be planted directly in soil or water.
Hydroponics
Hydroponics is a relatively new and innovative method used in propagating Rorippa nasturtium-aquaticum. In this method, the plants are grown in nutrient-rich water instead of soil. It's a great technique when growing Rorippa nasturtium-aquaticum in areas that do not have access to clean water or where the soil is contaminated.
Hydroponics involves placing the seeds or the plant cuttings in a net pot or directly suspending them in water. This method provides a faster growth rate and higher yield than traditional growing methods.
Disease and Pest Management for Rorippa nasturtium-aquaticum (L.) Hayek
Rorippa nasturtium-aquaticum (L.) Hayek, commonly known as watercress, is a semi-aquatic plant that requires a lot of water to grow. This plant is susceptible to various diseases and pests that can cause significant damage to the crop if left untreated. Therefore, it is essential to manage these problems to achieve a healthy and productive watercress crop.
Common Diseases
One of the most common diseases affecting watercress is bacterial soft rot caused by the bacterium Erwinia carotovora. Symptoms include soft, water-soaked areas that quickly turn slimy and rotten. In severe cases, the whole plant can collapse and die. To manage bacterial soft rot, it is essential to maintain good hygiene and sanitation practices in the growing area. Cutting and handling tools must be clean and disinfected, and diseased plants must be removed and destroyed immediately.
Another significant disease affecting watercress is downy mildew caused by the fungus Peronospora parasitica. It causes yellowing and stunting of the plant, and the undersides of the leaves will display a grayish-purple mold. To manage downy mildew, it is important to keep the growing area dry and well-ventilated, and monitor the plant's health regularly. Infected plants should be removed and destroyed quickly to prevent the spread of the disease.
Common Pests
Aphids are common pests that can cause significant damage to watercress. They suck the sap from the plant's leaf and stem, causing stunted growth, yellowing, and wilting. Control measures involve monitoring the population of aphids and introducing natural predators such as ladybugs and lacewings. Insecticidal soap can also be used to control aphids.
Slugs and snails are also common pests that can cause significant damage to watercress. They feed on the leaves and stem of the plant and can cause significant damage if left unchecked. Control measures involve monitoring the growing area, removing dead leaves and debris, and handpicking the slugs and snails. Additionally, barriers such as copper tapes and eggshells can deter them from reaching the growing area.
Conclusion
Overall, managing diseases and pests is essential for a healthy and productive watercress crop. Preventative measures such as good hygiene and sanitation practices, monitoring the plant's health, and introducing natural predators can go a long way in preventing diseases and pests from damaging the crop. Quick action and prompt removal of diseased plants and pests are also essential to prevent the spread of diseases and pests to healthy plants.
