Citrus Greening (HLB) Control

Symptoms

Caused by a bacterium spread by the citrus psyllid. Leaves show blotchy, asymmetrical yellow mottling that does not match on both sides of the midrib, along with vein yellowing. Fruits stay small, lopsided, fail to colour fully, and the juice tastes bitter. Trees decline branch by branch and may die in a few years.

Damage

Citrus greening, also called Huanglongbing, is considered the most serious citrus disease in the world. There is no cure, and infected trees become unproductive and can die within about five years. It steadily destroys orchards, lowers fruit quality and yield, and threatens the whole citrus industry where it spreads.

Organic & cultural control

Start with certified disease free budwood and saplings, since the disease often enters on infected nursery plants. Inspect regularly and promptly remove and destroy any tree confirmed with greening to cut the bacterial source. Control the citrus psyllid vector by conserving natural enemies, spraying neem oil, and managing flush growth, and remove alternate hosts that harbour the psyllid.

Chemical control

Since the disease itself cannot be cured, chemical effort targets the psyllid vector with recommended systemic insecticides timed to protect new flush, often combined with area wide management so the whole region sprays together. Always read and follow the label, observe the pre-harvest interval, protect bees, and consult your KVK or agronomist before spraying.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Plant only certified disease free saplings from reliable nurseries. Survey orchards routinely and rogue out infected trees early before the psyllid spreads the bacterium. Manage the citrus psyllid across the whole area, keep trees vigorous with balanced nutrition and micronutrients, and avoid bringing in unverified planting material.