Overview of Stevia viscida Kunth
Stevia viscida Kunth is a perennial herbaceous plant that belongs to the Asteraceae family. The plant is native to South America and can be found in countries like Bolivia, Argentina, and Peru. The common names for this species are Viscid Stevia and Yerba Dulce. Stevia viscida is known for its sweet-tasting leaves that are commonly used as a sweetener and traditional medicine in South America.
Appearance of Stevia viscida Kunth
Stevia viscida Kunth is a small shrub that reaches a height of up to 100cm. The plant has a woody base and hairy stems that are covered with glandular trichomes. The leaves of Stevia viscida are small, ovate, and have serrated margins. The plant produces inflorescence in clusters that contain small white or yellow flowers. The fruit of Stevia viscida is an achene that contains a small seed.
Uses of Stevia viscida Kunth
The leaves of Stevia viscida contain compounds that are 40-300 times sweeter than table sugar. The sweet-tasting compounds in the leaves are called steviol glycosides. These compounds are used as a natural sweetener in South America and countries around the world. Stevia viscida has been traditionally used as a medicinal plant to treat various ailments such as diabetes, hypertension, and digestive disorders. The plant's dried leaves and extracts are used in the preparation of herbal tea, beverages, and food products.
In conclusion, Stevia viscida Kunth is a small shrub that produces sweet-tasting leaves commonly used as a natural sweetener and traditional medicine in South America. The plant's small white or yellow flowers and achenes add to its beauty. The plant is easy to cultivate and presents itself as an alternative to artificial sweeteners used by the food and beverage industry.
Light Requirements
Stevia viscida Kunth requires bright, indirect sunlight for optimal growth. However, it can also grow in partially shaded areas. Direct sunlight exposure can cause leaf burn and stunted growth in the plant.
Temperature Requirements
The plant can grow in a range of temperatures between 15°C to 30°C. The optimal temperature range for the growth of Stevia viscida Kunth is between 20°C to 25°C. If the temperature falls below 10°C or rises above 35°C, the plant growth is negatively affected. The plant can tolerate mild frost but cannot withstand prolonged exposure to freezing temperatures.
Soil Requirements
Stevia viscida Kunth requires well-drained, fertile soil for optimum growth. The soil should have a pH range of 6.5 to 7.5. Sandy loam soils with good organic matter content are suitable for the growth of this plant. The soil should be moist but not waterlogged as waterlogging can lead to root rot and fungal diseases in the plant. The addition of compost or rotted manure can greatly enhance the quality of the soil and promote healthy plant growth.
Cultivation Methods of Stevia viscida Kunth
Stevia viscida Kunth is a perennial herb and can be propagated either by seeds or vegetatively by stem cuttings. The ideal planting season for the Stevia viscida Kunth is during the early spring season when the temperature is mild, and the soil is moist. So, plant the cuttings in a soilless potting mix containing organic material like peat moss, perlite and vermiculite.
After planting, make sure to place the pots in a warm and humid place with enough light shade for a few weeks until the plants establish well.
Watering Needs of Stevia viscida Kunth
Stevia viscida Kunth requires moderate to regular watering throughout the growing season. You should water plants once the top layer of the soil feels dry to the touch. Do not allow the soil to dry out completely or to remain soggy, as either condition can be problematic for the plant. Keep the soil moist but allow it to drain well, as Stevia is prone to root rot. In hot weather, it may be necessary to water more frequently to keep the plant hydrated.
Fertilization of Stevia viscida Kunth
Stevia viscida Kunth requires regular feeding with a balanced fertilizer that contains nitrogen, phosphorus, and potassium. Consider using a slow-release granular fertilizer for providing essential nutrients to the plant throughout the growing season. Apply fertilizer every two weeks during the spring and summer months, and reduce the frequency to once a month in the fall.
Pruning of Stevia viscida Kunth
Pruning is an essential activity for keeping Stevia viscida Kunth healthy and productive. The best time to prune is during early spring, before new growth occurs. Prune the plant back to about four inches above the soil line to encourage new growth. You should prune Stevia viscida Kunth regularly, especially during the summer months, to promote bushy growth and prevent the plant from becoming too woody. Remove any yellow or damaged leaves, as this can help prevent pest and disease problems.
Propagation of Stevia viscida Kunth
There are different methods of propagation for growing Stevia viscida Kunth. These include:
Seed Propagation
Seeds can be sown directly into well-prepared beds in the garden or started indoors under controlled conditions. The seeds should be sown in light, well-drained soil or seed-starting mix and kept evenly moist, but not waterlogged. Germination typically occurs within 7-14 days. The seedlings can be transplanted to their permanent positions once they are about 3-4 inches tall and have developed strong roots.
Division Propagation
Stevia viscida Kunth can also be propagated by dividing mature plants. This is usually done in the spring or fall when the plant is not actively growing. The plant is dug up and gently separated into smaller sections, ensuring that each new section has a healthy root system. The divided sections can be transplanted to new locations or container-grown.
Cutting Propagation
Another propagation method for Stevia viscida Kunth is cuttings. Softwood cuttings are taken from the current season's growth in the early summer when the plant is actively growing. Cuttings should be about 3-4 inches long, and the lower leaves should be removed. The cuttings are then dipped in rooting hormone and planted in a well-drained soil mixture. They should be covered with a plastic bag and kept in a warm, bright spot until roots develop, usually within 4-6 weeks. Once the cuttings have rooted, they can be transplanted to their permanent positions.
Layering Propagation
Layering is a propagation method that is best done in the spring or fall. A low-growing branch of the plant is bent down and buried in a shallow trench. The tip of the branch should be exposed above ground. The buried section of the branch will develop roots, and eventually, a new plantlet will form. Once this occurs, the new plant can be separated from the parent plant and transplanted.
Disease Management for Stevia Viscida Kunth
Stevia viscida Kunth is an important herbal crop with tremendous economic value due to its high content of stevioside, a natural low-calorie sweetener. However, the plant is susceptible to several diseases, which can cause significant losses to farmers and reduce the quality of its leaves. Below are some of the common diseases affecting Stevia viscida Kunth and ways to manage them.
Powdery Mildew
Powdery mildew is a common fungal disease that affects the leaves of Stevia viscida Kunth, causing them to develop white powdery spots. The disease is favoured by high humidity and temperatures. To manage powdery mildew, farmers should spray with fungicides, prune and remove the infected leaves and maintain low humidity levels in the growing area
Anthracnose
Another fungal disease that affects the leaves of Stevia viscida Kunth is anthracnose. The disease is characterized by the appearance of black spotting on the leaves. To manage anthracnose, farmers should remove and dispose of the infected leaves, apply fungicides, and ensure good drainage to reduce humidity levels around the plant.
Pest Management for Stevia Viscida Kunth
Stevia viscida Kunth is also susceptible to various pest infestations, which can cause considerable damage to the plant. Below are some of the common pests known to attack Stevia viscida Kunth and ways to manage them.
Aphids
Aphids are small, soft-bodied insects that suck the sap out of Stevia viscida Kunth leaves. The affected leaves may turn yellow, curl up, and eventually die. To manage aphids, farmers should remove the infected leaves, spray with insecticides, and release natural enemies such as ladybird beetles or lacewings.
Spider Mites
Spider mites are tiny pests that feed on the undersides of leaves, causing them to turn yellow or bronze. To manage spider mites, farmers should control weeds, improve air circulation around the plant, and remove infested leaves. They can also spray the plants with insecticidal soap or neem oil.
Cutworms
Cutworms are the larvae of several species of moths that feed on the stems of Stevia viscida Kunth, causing wilting, stunted growth, and the eventual death of the plant. To manage cutworms, farmers should handpick the insects, apply insecticides, and use physical barriers such as mesh or cardboard collars around the base of the plants.
