Overview
Microcitrus australis (Planchon) Swingle, also known as Australian round lime or finger lime, is a small shrub-like tree belonging to the Rutaceae family. This plant is native to the subtropical rainforests near the eastern coast of Australia.
General Appearance
The Australian round lime plant has a unique and captivating appearance. It typically grows to a height of 2-7 meters and has a thorny and bushy appearance. The leaves of the plant are glossy green, slightly curled, and have a length of 4-7cm. The flowers are small, white, and star-shaped. The fruits are cylindrical, elongated, and have a length of 5-10cm. The color of the fruit varies from pink and green to gray and sometimes black.
Common Names
The Australian round lime is known by different names in different regions. In addition to the scientific name, the plant is also called Longnan in China, Dooja in India, and Finger Lime in the United States.
Uses
The Australian round lime is widely used in various food and medicinal applications. The tangy and zesty lime flavor of the fruit makes it an excellent ingredient in various dishes, including salads, cocktails, and desserts. The fruit is also used as a garnish due to its unique shape and color. Apart from culinary use, the fruit is believed to have medicinal properties and been used in traditional medicine for treating digestive issues, rheumatism, and microbial infections.
The plant is relatively easy to cultivate and is grown for both commercial and domestic purposes. It is ideal for home gardens due to its ornamental appeal and the flavor of the fruit.
Light Requirements
Microcitrus australis requires full sun to grow properly. It prefers at least six hours of sunlight every day. Lack of enough sunlight can result in stunted growth or reduced fruit production.
Temperature Requirements
The appropriate temperature range for Microcitrus australis is between 15°C and 25°C. The plant will not thrive in freezing temperatures but is also sensitive to extreme heat, particularly when humidity is high. Temperatures above 30°C during flowering and early fruit development can lead to fruit drop or poor fruit quality.
Soil Requirements
The ideal soil for Microcitrus australis is well-drained, acidic with a pH of 5.5 - 6.5, and rich in organic matter. The plant performs well on sandy loam soils. However, it can grow on other types of soils provided they meet the above soil requirements.
Cultivation Methods
Microcitrus australis, commonly known as the Australian lime or lime berry, is a small evergreen tree that is native to Australia. The plant is easy to grow and can be propagated from seeds or cuttings. Place the seeds in a well-drained potting mix, keep it moist, and warm until the seedlings appear. Ensure that the seedlings receive adequate light and maintain a temperature range of 20-25°C.
Watering Needs
When establishing the Australian lime tree, frequent watering is crucial. The tree should be watered in the morning and late afternoon during the first growing season to aid in root establishment. As the tree matures, it requires less watering and is tolerant of dry conditions.
Fertilization
It is recommended to fertilize the Australian lime tree two times a year; once in spring and the other time in summer. Fertilizers containing nitrogen, phosphorus, and potassium (NPK) in equal proportions are ideal. Other nutrients such as magnesium and iron are also essential. Always follow the recommended dosage indicated on the package, and avoid over-fertilizing as it can damage the plant.
Pruning
Pruning Microcitrus australis is not necessary, but it can improve fruit yield and quality. Pruning involves removing dead, damaged, or diseased branches and shaping the plant to a desired size and form. The best time to prune is during the winter months when the tree is dormant. Always use sharp, clean tools to avoid damaging the tree and remove no more than one-third of the foliage.
Propagation of Microcitrus australis
Microcitrus australis, commonly known as the Australian finger lime, is a small tree or shrub native to Australia. Propagation of this plant can be done through several methods:
Seed Propagation
Seeds from ripe fruits can be collected and sown in a well-draining soil mix. The seeds should be cleaned and soaked in water for a day or two before planting. They should be planted in individual pots or trays and kept in a warm, humid location. Seedlings can take up to several months to germinate and should be transplanted to larger containers once they have developed a few leaves.
Cuttings
Microcitrus australis can be propagated through hardwood cuttings taken from mature trees. The cuttings should be about 20-30cm long and 6mm thick. They should be dipped in a rooting hormone and planted in a mix of sand and peat moss. The cuttings should be kept in a warm location with high humidity until they have rooted. This can take several months. Once rooted, the cuttings can be transplanted to larger containers or the field.
Air Layering
Air layering can be done on mature plants in order to propagate them. A section of the stem is wounded and treated with rooting hormone. A ball of moist peat moss or sphagnum moss is then wrapped around the wounded area and covered with plastic. Roots will develop at the wounded area and can be cut off from the parent plant once they are well-developed.
Grafting
Grafting is another method of propagating Microcitrus australis. It involves joining a scion, or a small branch with buds, from the desired variety onto a rootstock. This method is commonly used to propagate cultivars that are not able to produce viable seeds. Grafted plants are usually stronger and more disease-resistant than those propagated through other methods.
Disease and Pest Management for Microcitrus australis
Microcitrus australis, commonly known as the Australian finger lime, is a fruit-bearing tree that is susceptible to a number of diseases and pests. Proper management can help to prevent or control these issues.
Common Diseases
One of the most common diseases affecting Microcitrus australis is citrus canker. This bacterial disease causes yellow halo-like lesions on the leaves, stems, and fruit of the tree. To prevent infection, avoid planting trees in areas known to have the disease and keep the trees well-spaced to encourage good air circulation. If citrus canker is present, infected trees should be removed and destroyed.
Another disease that can affect Microcitrus australis is citrus greening, also known as Huanglongbing (HLB), which is caused by a bacteria called Candidatus Liberibacter asiaticus. The disease causes yellowing of leaves, splotchy mottling and twig dieback. There is no cure for this lethal disease and it is not under control. To avoid the disease, buy certified healthy plants from reputable nurseries, control the vector psyllids and provide proper nutrition and watering to sustain the plants' health.
Common Pests
When it comes to pests, the most common problem for Microcitrus australis is the citrus leafminer. These small pests create squiggly lines on leaves as they tunnel through them. To manage citrus leafminers, regular monitoring of the trees and insecticides when necessary can be done.
The Asian Citrus Psyllid (ACP) is another serious pest of Microcitrus australis as it feeds on the sap of young leaves and stems, and produce toxic saliva, which can affect plant vigor and serve as a vector for HLB disease.Neem oil, spinosad, and insecticidal soap can help to control ACP. Yellow sticky traps can also be installed to monitor and trap adult psyllids.
Integrated Pest Management
Integrated pest management (IPM) is a sustainable, eco-friendly approach to pest and disease control that combines various techniques like cultural, chemical and other control strategies based on the pest and the local ecosystem to minimize pesticide use. Implementing good sanitation practices like removing fallen leaves, pruning diseased twigs and the use of beneficial insects and organisms that predate on pests, like ladybugs and lacewings, can help to reduce the pest pressure.
Overall, with careful attention to disease and pest management, growers can protect their Microcitrus australis trees and enjoy a healthy harvest of these unique fruits.
