Pest & Disease Citrus greening (Huanglongbing disease)

Citrus greening (Huanglongbing disease)

Candidatus Liberibacter asiaticus

Also Known As - Huanglongbing disease (Citrus greening)

What is Citrus greening (Candidatus Liberibacter asiaticus)?

Citrus greening, or Huanglongbing (HLB), is caused by Candidatus Liberibacter asiaticus bacteria, transmitted by insects called Asian citrus psyllids (Diaphorina citri). The disease affects various citrus species, including oranges, grapefruits, lemons, limes, and tangerines, among others. Symptoms of citrus greening include yellowing of veins, mottling of leaves, premature defoliation, twig dieback, root decay, stunted growth, off-season flowers, small irregular fruit with a bitter taste, and, in severe cases, plant death.

How does Citrus greening (Candidatus Liberibacter asiaticus) occur?

The bacterium Candidatus Liberibacter asiaticus, causing citrus greening, reproduces within the Asian citrus psyllid vector. Infected psyllids transmit the bacteria while feeding on citrus trees. Within the psyllid's gut and reproductive organs, the bacteria multiply. When the psyllid feeds on healthy trees, it injects the bacteria into the phloem, causing systemic infection. Temperature plays a significant role in the interaction between the bacteria and the insect vector.

Symptoms

1 - Impact on plants

HLB-infected citrus trees exhibit premature defoliation, twig dieback, root decay, stunted growth, off-season flowers, and small irregular fruit. Bitter taste results from disrupted phloem nutrient transport, reducing productivity and risking tree death.

2 - Impact on Soil and Environment

• HLB itself does not directly impact soil health but it can affect nutrient cycling and organic matter decomposition. • Additionally, the removal of infected trees and changes in the landscape can impact regional biodiversity.

Solutions

1 - Cultural Practices

1. Maintain overall plant health through proper fertilization, irrigation, and pruning practices. 2. Use certified disease-free nursery stock for planting. 3. Regularly monitor trees for symptoms and use early detection methods for prompt identification. 4. Remove and destroy infected trees to prevent further spread. 5. Support research and development of HLB-resistant citrus varieties.

2 - Chemical Control

• No antibiotics or specific chemical treatments are available to cure Citrus Greening (HLB). • Integrated pest management (IPM) strategies focus on controlling the insect vectors to manage the disease. • Streptomycin and oxytetracycline antibiotics have been used in the United States on an emergency basis against citrus greening disease. Their use is banned in Brazil and the European Union. • Expansion of antibiotic use is proposed but opposed due to concerns about antibiotic resistance and human health impacts.

Susceptible Species

FAQ

Do shade growing plants need any Sunlight?

Shade growing plants do need sunlight, although they require less than other plants. They need some direct sunlight each morning to help them photosynthesize and grow properly. Also, indirect sunlight throughout the day helps them stay healthy. Shade growing plants will benefit from the sunshine, but if they get too much or too little, then they can suffer the consequences. It's important to pay attention to the needs of your plants so that you can provide them with the proper light for optimal growth.

How often should you water indoor plants?

Indoor plants should be watered when the soil feels dry to a depth of about two inches, usually about once a week. A helpful technique to determine your plants' watering needs is to feel the soil before and after watering to get a sense of how long it takes to dry out. An important note to remember is that some plants require less water than others, and it's best to research the specific needs of your individual plants. Likewise, if your home is very dry, you might need to water more often as the lack of moisture can stress the plants and lead to problems like brown leaves and wilted stems.

Can my monstera plant get root rot?

Yes, a plant can get root rot. Root rot is a fungal disease that can be caused by over-watering, poor soil drainage, or high humidity levels in the air. Signs of root rot include yellowing leaves, wilting and stunted growth, and damaged or browning root systems. Sometimes it is difficult to detect root rot until the plant is removed from the soil, as the problems are mainly below the soil surface. Treating root rot usually involves removing the affected parts of the plant and replanting the unaffected ones.

Can I put my Monstera outside in summer?

No, you should not put your Monstera outside in summer. Monstera plants need warm, humid air to thrive, and direct sunlight can scorch their leaves. Instead, put your Monstera in a bright, sunny spot with indirect light, making sure the sun never directly hits the leaves. During the summer, keep your Monstera's soil damp and mist it occasionally to keep the leaves hydrated. At nighttime, keep the temperature around 16 - 21°C (60 - 70°F). You can definitely take your Monstera outdoors for short periods of time, just make sure to bring it back in if it starts to get too hot.

What happens if my monstera plant gets too cold?

If your monstera plant gets too cold, it will become vulnerable to pests, disease, or other damage. Cold temperatures can damage the leaves of the plant, causing them to become spotted or limp. The roots of monstera plants may also suffer in cold temperatures, leading to root rot or other diseases. Belonging to the tropical family, monsteras are used to warm environments and do not do well in cold temperatures, so it is important to ensure your plant is kept in conditions that suit their needs.

Is it possible to grow a vegetable garden in a small space?

Yes, it is possible to grow a vegetable garden in a small space. Gardening in a small space can be as simple as growing a few containerized plants in pots and raised beds, or as elaborate as vertically stacking planters, hanging pouches, and hanging baskets on a wall, railing, or fence. Regardless of the size of the space you are working with, some simple techniques such as companion planting, organic fertilizers, and water conservation can help you get the most out of your small vegetable garden.

Is peppermint herb green good for digestion?

Peppermint herb is indeed beneficial for digestion. The flavonoids in the herb support digestion by reducing inflammation in the digestive track, aiding in digestion and relieving indigestion, heartburn, and even the symptoms of irritable bowel syndrome. Additionally, peppermint is naturally rich in menthol, which helps to relax the muscles of the stomach, aiding in the digestion of food. Peppermint herb can be consumed in a variety of forms, such as teas, tinctures and capsules, as well as by adding the herb to food or directly to water or tea.

Should peppermint herb green be consumed daily?

No, peppermint herb green should not be consumed daily. This is because it contains high levels of menthol, which can be toxic if taken in large doses. Additionally, consuming large amounts of peppermint herb green could interfere with the absorption of essential minerals and vitamins, potentially causing vitamin deficiencies. For these reasons, it is best to consult with a doctor before incorporating peppermint herb green into your daily diet.