HLB - Citrus Greening Disease

HLB, also known as citrus greening disease, is fatal for citrus trees.

Once a tree becomes infected, there is no cure and it will die. Spread by an insect called the Asian citrus psyllid.

The disease, first found in Southern California in 2012, destroys production leading to bitter, inedible, misshapen fruit.

While research is on-going, there is increasing evidence that balanced nutrition can mitigate against HLB. For example, there is increasing evidence that citrus trees prefer the nitrate form of nitrogen and can experience toxicity to ammonium forms of N.

These increasing ammonium concentrations in the soil can also reduce uptake of potassium, calcium and magnesium and trees can test positive for, and exhibit, HLB Greening symptoms.

In contrast, while trees with adequate levels of potassium, calcium and magnesium, don't exhibit the symptoms of HLB even if they test positive for the disease.

Your Yara agronomist or fertilizer supplier will be able to provide more information on this effect as the fast-track research continues.