Citrus HLB Management

HLB-Huanglongbing, other names yellow dragon disease or citrus greening is the world’s deadly diseases of citrus.

Damage:The HLB bacteria can infect most citrus cultivars, species and hybrids and even some citrus relatives. Leaves of newly infected trees develop a blotchy mottle appearance.

On chronically infected trees, the leaves are small and exhibit asymmetrical blotchy mottling (in contrast to Zinc deficiency that causes symmetrical blotching).

Fruit from HLB-infected trees are small, lopsided, poorly colored, and contain aborted seeds. The juice from affected fruit is low in soluble solids, high in acids and abnormally bitter. The fruit retains its green color at the navel end when mature, which is the reason for the common name “citrus greening disease.” This fruit is of no value because of poor size and quality. There is no cure for the disease and rapid tree removal is critical for prevention of spread.

Economic Impact: HLB is one of the most devastating diseases of citrus and since its discovery in Florida in 2005, citrus acreage in that state has declined significantly.

If the disease were to establish in California, the nursery industry would be required to move all of their production under screenhouses, pesticide treatments for the vector would be instituted resulting in greatly increased pesticide costs (3-6 treatments per year) and indirect costs due to pesticide-induced disruption of integrated pest management programs for other citrus pests. A costly eradication program would need to be instituted to remove infected trees in order to protect the citrus industry.

How to decrease or avoid the loss?

National and international quarantines are critical to minimize the potential of long-distance dissemination. Integrated pest management strategies are needed such as:

  • early detection,
  • chemical and biological control of the vectors,
  • potential chemical control of the Liberibacters using chemical and antibiotic treatments of trees,
  • isolation and protection of budwood sources and plant propagation in screened-in, insect-proof locations, and
  • development of resistant cultivars.

Below series of products from Lin Chemical for citrus HLB management

HLB detection kit for early detection to find HLB trees at earlier stage, to save cost for farmers and to distinguish HLB from other disease caused by lack of element or nematode attack.

Insect-attracting sticky yellow board+biological(BEAUVERIA BASSIANAMineral Oil…) & chemical combination management for citrus HLB vectors like citrus psyllids.

Citrus HLB Restorative-Repair the damaged parts of Huanglongbing and improve the plant’s disease resistance and immunity to prevent/ protect citrus trees from HLB.