CITRUS greening, a disease which two years ago threatened to wipe out Jamaica's orange groves, may prove to be a blessing in disguise.
Fruit-juice company Trade Winds Citrus, maker of Tru-Juice, said the treatment it has employed for the past 18 months is not just controlling the infection, also known by its Chinese name, huanglongbing or yellow dragon disease.
The chemical spray, which costs US$200 ($18,000) per acre, could raise orange production to double the level before the bacteria struck in 2009.
The company used to produce 300 boxes — each weighing 90lb (41kg) — per acre but managed only 215 last year. This year it's forecasting 280 boxes and if it matches yields in Florida, it could see 600 in a year or two.
"If it gets to 450, I'm smiling," Trade Winds Managing Director Peter McConnell said yesterday. "The trees needed more food but we were short-changing them."
The new plant medicine includes insecticides to control the jumping plant lice (technically known as psyllids, cousins of aphids) that feed off the trees' sap and incidentally infect them with the bacteria.
But the revolutionary ingredient is a hefty dose of extra fertiliser, mostly nitrogen, phosphorus and potassium, with micro-nutrients such as magnesium and sulfur added to the mix.
The idea, developed in the US, was to strengthen the plants so that their immune systems could fight the invading bacterium better.
Farm workers spray the formula on the trees three to six times a year.
At Trade Wind's New Works farm in Linstead, the programme has restored trees that were almost dead to robust health.
The result has been so strong that farm's manager, David Taylor, asked his boss recently: "Was greening a curse or a blessing?"
Yellow dragon disease is described by the US Department of Agriculture as one of the "more serious" citrus diseases. America has quarantined areas where the illness is common.
After huanglongbing struck Jamaica, many of the country's estimated 5,000 citrus farmers simply abandoned their groves, allowing trees that had been productive for decades to become stumps.
By the summer of 2011, as the Ministry of Agriculture ordered the nation's citrus nurseries closed, Tru-Juice was urging small farmers to persevere, noting that prices were high.
Tru-Juice initially followed an action plan introduced in Brazil in which infected trees were dug up and replaced by fresh stock.
But it soon became apparent that this would mean replacing every tree the company owned on its 2,750 acres.
Taylor says DNA tests indicate that almost all the plants on his farm are infected, even if they don't yet show the typical symptoms — patchy fading of the green colour in the leaves.
A female jumping louse can lay as many as 2,000 eggs on a tree, said Alfred Barrett, a programme manager with the Jamaica Citrus Protection Agency, which, along with the UN Food and Agriculture Organisation, has been backing the fight against greening.
The bacteria, Liberibacter asiaticus, live in the phloem, the plant equivalent of blood, and gradually block up the veins carrying nutrients and water.
Essentially, the plants starve to death.
Trade Winds is also experimenting with other treatments, including biological controls such as a parasitic wasp that lays its eggs in the lice before they mature.
Roger Clarke, minister of agriculture, who managed New Works farm when he was younger, said the condition of the trees on the estate was "encouraging".
"I can only hope that other farmers will do likewise," he said. " We have to come together to find a common strategy for saving our citrus industry."