Citrus
The cause of the disease has not been determined yet. There is no known cure for citrus blight and once trees begin to decline, they never recover.
Severe pruning of blighted trees will result in temporary vegetative recovery, but tree production drops again once they come back into production.
Although crop nutrition cannot eradicate the effects or control citrus blight there is increasing evidence that nutrition strengthening the tree can help mitigate the disease effects.
Research in Florida across three citrus varieties confirms that tree loss due to citrus blight is significantly lower where calcium nitrate is a major component of the fertilizer program. The most responsive variety was Hamlin where tree death was halved.
Increased field evidence suggests that the use of calcium nitrate fertilizers helps reduce the impact of citrus blight. Trees are more productive and live longer than those in groves treated with ammonium nitrate. They generally have greater foliage, more vigor, and produce larger diameter, heavier fruit, with more juice.
Asia and Oceania