Description of Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh.
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. is a species of flowering plant in the family Fabaceae. This plant is commonly known as purple crotalaria or hairy rattlepod. It is native to southern Africa and has been introduced to other parts of the world, such as Australia and the United States.
General Appearance
Purple crotalaria is a herbaceous perennial with an erect growth habit. It can grow up to 2 meters tall and has a slightly woody stem that is hairy. The leaves are alternate, oblong, and hairy, measuring about 15-30 cm long and 3-6 cm wide. The flowers are purple, pea-like, and are arranged in racemes at the end of the stem. The fruit is a cylindrical pod measuring about 2-4 cm long and covered with velvety hairs.
Uses
Purple crotalaria has been traditionally used in some African countries to treat fever, malaria, and other medical conditions. It is also known to have insecticidal properties that can help control pests such as aphids and spider mites. Furthermore, it is used as a cover crop in agriculture due to its ability to fix nitrogen in the soil.
However, it is important to note that some species of crotalaria, including the purple crotalaria, contain toxic alkaloids that can harm livestock that graze on the plant. Hence, it is advisable to use this plant with caution and to seek expert advice before using it for any purpose.
Light Requirements
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. requires full sun exposure for optimal growth and development. It cannot tolerate shaded areas, and partial shade can adversely affect its growth and flowering patterns. Therefore, it is recommended to plant this species in areas where there is full sun exposure.
Temperature Requirements
This plant thrives in hot and dry environments, making it adapted to hot and tropical climates. The ideal temperature range for growth is between 25-35°C. However, extremely high temperature can lead to wilting or drying of the plant. Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. can tolerate drought conditions but for a limited period and not in waterlogged soil conditions. Therefore, it is important to ensure an adequate water supply and avoid excessive moisture in the soil.
Soil Requirements
The plant prefers well-draining sandy soils with a pH range of 6.0 to 6.5. It also thrives in soils that have high organic matter content. It has the ability to survive under low fertile soil conditions but does not grow well under such conditions. Therefore, adding fertilizers can help to improve growth and flowering patterns.
Cultivation Methods
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. grows best in warm and dry climates, so it is essential to choose a location that receives plenty of sunlight. When planting seeds, it is important to plant them in well-draining soil with a neutral or slightly acidic pH level. The plant prefers soil with a high concentration of nitrogen, so adding compost to the soil can be helpful in providing the necessary nutrients. Planting in raised beds can also be beneficial to ensure proper drainage.
Watering Needs
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. does not require a lot of water and is relatively drought-tolerant. However, it is important to water the plant regularly during the first few weeks after planting to help establish its roots. Once the plant is established, it can go for extended periods without water. It is best to water deeply and infrequently to encourage deep root growth.
Fertilization
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. requires a high concentration of nitrogen, so adding a nitrogen-rich fertilizer every 4-6 weeks can be beneficial. Compost or other organic fertilizers can also be used to provide the necessary nutrients. It is important not to over-fertilize, as this can lead to excessive foliage growth at the expense of flower production.
Pruning
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. does not require much pruning, but deadheading spent flowers can help prolong the blooming period and encourage the production of new flowers. Any dead or damaged branches should be pruned away in the spring to encourage new growth and ensure the plant's health. It is also important to remove any seeds as they can be toxic to livestock if ingested.
Propagation of Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh.
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh., or commonly known as purple hoary pea, is a perennial flowering plant that is commonly found in tropical and subtropical regions. This plant is known for its beautiful purple flowers and its ability to fix nitrogen in the soil. Propagation of Crotalaria incana L. subsp. purpurascens can be done through various methods.
Propagation through Seeds
Propagation through seeds is the most common way to propagate Crotalaria incana L. subsp. purpurascens. The seeds can be obtained from the mature seed pods of the plant. These pods usually dry on the plant and can be collected when they turn brown and start to split open. To ensure good germination rates, the seeds need to be scarified, which means scratching the seed coat, to allow moisture to penetrate it. The scarified seeds can be sown in pots or directly in the field. When sowing in pots, it is advisable to use well-draining soil and to keep the soil moist until germination occurs.
Propagation through Cuttings
Crotalaria incana L. subsp. purpurascens can also be propagated through cuttings. Softwood cuttings can be taken from the plant during the growing season. The cuttings should be around 5-6 inches long and should have a few leaves attached to them. The cuttings should be dipped in rooting hormone and then planted in a well-draining soil mix. The soil should be kept moist, and the cuttings should be kept in a shaded area until roots develop.
Propagation through Division
Crotalaria incana L. subsp. purpurascens can also be propagated through division. This method is best done when the plant is dormant. The plant can be dug up, and the roots can be gently separated into smaller clumps. Each clump can then be planted in a new location or container. It is important to ensure that each clump has some roots and shoots to ensure successful propagation.
Disease Management
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. is susceptible to various diseases that can cause significant damage and yield losses. Some of the most common diseases that can affect this plant include:
- Crotalaria blight: This disease is caused by the fungus Cercospora crotalariae and can cause leaf spot, stem dieback, and defoliation. The disease can be managed by avoiding overcrowding, maintaining proper plant hygiene, and applying fungicides early in the infection.
- Root rot: It is caused by the fungus Fusarium solani and can cause wilting, yellowing, and eventual death of the plant. The disease can be managed by planting in well-drained soils, avoiding over-irrigation, and using fungicides as a preventative measure.
- Mosaic virus: This virus causes mosaic patterns on the leaves, stunted growth, and reduced yield. The disease can be managed by removing and destroying infected plants, avoiding plant stress, and using virus-free seeds.
Pest Management
Crotalaria incana L. subsp. purpurascens (Lam.) Milne-Redh. is also susceptible to various pests that can cause significant damage and yield losses. Some of the most common pests that can affect this plant include:
- Spider mites: These tiny pests feed on the plant's sap, causing yellowing and stunted growth. They can be managed by spraying the plant with insecticidal soap or neem oil.
- Cutworms: These larvae of nocturnal moths can cut the plant at the base and cause wilting and death. The pests can be managed by manually removing them, placing barriers around the plant stems, and using biological control such as Bacillus thuringiensis.
- Whiteflies: These small, winged insects feed on the plant's sap, causing yellowing and stunted growth. They can be managed by spraying the plant with insecticidal soap or neem oil.
