Origin and Common Names
×Citroncirus webberi J. Ingram & H. Moore, commonly known as Webber citrange, is a citrus hybrid plant produced by crossing trifoliate orange (Poncirus trifoliata) and Citrus paradisi (grapefruit). The plant was first created by Walter Tennyson Swingle and LD Batchelor at the United States Department of Agriculture in Brownsville, Texas, and was named after its breeder, Walter Tennyson Webber. It was released to the public in 1978.
Appearance
Webber citrange is a spiny shrub or small tree that can reach up to 5 meters in height. It has a dense, round, and spreading canopy with an average width of 4-5 meters. The leaves are trifoliate, with small oval-shaped leaflets that are 2-5 cm long and have a glossy dark green color. The plant produces fragrant white flowers with 5 petals that are 3-4 cm in diameter and bloom in late winter or early spring. The fruit of the Webber citrange is large, round, and orange, with a diameter of 7-8 cm. It has a thick rind and a juicy, acidic pulp.
Uses
The Webber citrange is primarily used as a rootstock for other citrus plants, particularly for grapefruit and mandarin varieties. Its resistance to citrus tristeza virus, Phytophthora citrophthora, and other soil-borne diseases make it a popular choice for growers. Additionally, it can tolerate poor soil conditions, drought, and cold temperatures better than other citrus rootstocks. The plant's fruit is edible, but it is not commonly consumed due to its sour taste.
Light Requirements
The ×Citroncirus webberi J. Ingram & H. Moore requires full sunlight to partial shade for optimal growth. The plant should be placed in an area that receives at least 6 hours of sunlight per day. Too much shade can lead to poor growth and decreased fruit production.
Temperature Requirements
The ×Citroncirus webberi J. Ingram & H. Moore is a warm-season plant that thrives in temperatures between 60-85°F (15-30°C). The plant cannot tolerate frost or freezing temperatures. In cooler climates, the plant can be grown in a greenhouse or protected area to maintain optimal temperatures.
Soil Requirements
The ×Citroncirus webberi J. Ingram & H. Moore requires well-draining soil that is rich in nutrients. The soil pH should be between 5.5-7.0, slightly acidic to neutral, for optimal growth. The plant can tolerate various soil types, including sandy, loamy, and clay soils, as long as they are well-draining. It is essential to avoid overwatering, which can lead to root rot and other issues.
Cultivation of ×Citroncirus webberi
When planting ×Citroncirus webberi, it is crucial to choose a location that receives plenty of sunlight. The plant requires at least six hours of direct sunlight every day. You should plant this citrus hybrid in well-draining soil. The soil should have a pH level of 5.5 to 6.5, which is slightly acidic.
Watering Needs
The plant ×Citroncirus webberi requires consistent watering, especially during the dry months. As a rule, you should water the plant once per week. However, this may vary depending on the climate and the soil type. Before watering the plant, check the soil moisture level, and water the plant only when the soil is dry to a depth of about 2 inches. Avoid overwatering the plant as this may cause root rot.
Fertilization
For optimal growth and fruit production, you should fertilize ×Citroncirus webberi three times a year. During the growing season, from spring to early summer, apply a slow-release fertilizer. In midsummer, apply a citrus fertilizer high in nitrogen. In fall, a fertilizer high in potassium will support fruit maturation.
Pruning
Pruning is essential in maintaining a healthy plant and maximizing fruit production. ×Citroncirus webberi needs minimal pruning. Remove damaged or diseased branches. Pruning should be done during the dormant period, either late fall or early spring. The plant produces fruit on new wood, so minimal pruning does not impact fruit production.
Propagation of ×Citroncirus webberi J. Ingram & H. Moore
The ×Citroncirus webberi J. Ingram & H. Moore plant can be propagated through several methods, including seed propagation, grafting, cutting, and budding.
Seed Propagation
Seeds can be collected from mature fruits and used for propagation. The seeds should be cleaned and soaked in water overnight. After soaking, the seeds should be sown in a well-draining potting mix and kept in a warm, humid location. The seeds should germinate within 2 to 3 weeks.
Grafting
Grafting is a common propagation method for citrus plants. A suitable rootstock can be selected and the desired scion can be grafted onto it. The graft union should be protected with grafting tape and the plant should be kept in a warm, humid location until new growth appears.
Cutting
Softwood cuttings can be taken from the plant in the spring or early summer. The cuttings should be about 6 inches long and should include at least 3 leaves. The cuttings should be dipped in rooting hormone and planted in a well-draining potting mix. The cuttings should be kept in a warm, humid location and misted regularly until new growth appears.
Budding
Budding is a technique where a bud is removed from the desired scion and inserted into a small incision made on the rootstock. The bud and the rootstock should be wrapped tightly with grafting tape and the plant should be kept in a warm, humid location until new growth appears.
Disease and Pest Management for ×Citroncirus webberi
×Citroncirus webberi is a hybrid plant created by crossing Citrus medica (citron) and Poncirus trifoliata (trifoliate orange). As with many other plants, this hybrid plant is not entirely immune to diseases and pests. This section will discuss some of the common diseases and pests that might affect the plant and provide suggestions on how to manage them.
Common Diseases
One of the most common diseases that can affect ×Citroncirus webberi is root rot. Root rot is usually caused by fungi that thrive in overly wet soil. To prevent root rot, it is essential to ensure that the soil is well-draining, and the plant is not overwatered. In addition, it is advisable to plant the plant in an elevated area. If the plant is already infected with root rot, it is best to remove the affected parts and treat the remaining parts with a fungicide.
Another common disease that can affect ×Citroncirus webberi is citrus canker. Citrus canker is a highly contagious bacterial disease that causes lesions on the leaves, fruit, and stems. To prevent citrus canker, it is important to avoid planting the plant in areas with a history of the disease. If the plant is already infected, it is best to remove the affected plant and dispose of it properly to prevent the spread of the disease.
Common Pests
One of the common pests that can affect ×Citroncirus webberi is the aphid. Aphids are small, soft-bodied insects that feed on the sap of the plant. They can cause stunted growth and yellowing of the leaves. To manage aphids, one can use insecticidal soap or neem oil. Another effective way of controlling aphids is by introducing natural predators like ladybugs.
Another common pest that can affect ×Citroncirus webberi is the citrus mealybug. Citrus mealybugs are small insects that produce a waxy substance that covers their bodies. They are usually found in clusters on the leaves and stems of the plant. To manage citrus mealybugs, one can use an insecticidal soap or a horticultural oil.
In conclusion, prevention is better than cure when it comes to managing diseases and pests in ×Citroncirus webberi. It is important to establish good cultural practices such as ensuring the plant is grown in well-draining soil, planting the plant in appropriate areas, and appropriate watering that promotes healthy growth. By following these management practices, it is possible to keep your plant healthy and free from diseases and pests.
