BUG THREATENS FLORIDA OJ CROP
Invasive insect spreading disease harmful to citrus groves
Florida oranges are threatened with destruction if scientists and the government can’t find a way to stop an Asian bug from spreading a tree-killing disease.
The harvest for the state’s signature fruit could plunge to 27 million boxes by 2026, according to an Oct. 21 report by the Florida Department of Citrus. That’s an 82 per cent drop from 149.8 million boxes in 2005, the year the bacterium that causes Huanglongbing, better known as citrus greening, was found in southern Florida.
The disease is spread by the Asian citrus psyllid, a tiny winged insect, and there’s currently no known cure. Greening already caused industry-wide losses of US$7.8 billion and more than 7,500 jobs between 2006 to 2014, the University of Florida estimates.
The outlook is “precarious” for Florida’s citrus industry, which “risks losing relevance and economic impact” in the long run if crop yields continue to fall and trees keep dying, the citrus department said in its Oct. 21 report.
The current harvest will shrink to 74 million boxes for the season that began Oct. 1, down 24 per cent from a year ago and the lowest since 1964, the U.S. Department of Agriculture said Nov. 9. The forecast signals the fourth consecutive seasonal decline, the longest slump since at least 1913, state data show. A box weighs 90 pounds (41 kilograms).
This is raising costs for Coca-Cola Co., maker of Minute Maid brands, and PepsiCo Inc., which sells Tropicana and Gatorade.
Demand for America’s favourite juice has fallen because of consumer perceptions about high calorie content and the rise of alternatives such as coconut water. Even so, Florida’s industry, which includes grapefruit and specialty citrus, still employs about 62,000 people and has an annual economic impact of US$10.7 billion on the state, according to Florida Citrus Mutual, the largest grower organization.
The invasive psyllid was first found in Florida in June 1998 and is now established throughout the state’s citrus-growing region. It feeds on the sap of tree leaves and can carry the bacterium that causes greening a mile without stopping. The insects live for about a month, and females can lay as many as 800 eggs in that time. A recent study by the University of Florida showed the bugs fly earlier in their life cycle, more frequently and farther when they are infected.
The bacterium blocks the passage of nutrients through a tree’s vascular system, producing leaves that have yellowing veins, yellow-green mottling and sometimes no green colouring at all. The yellowing typically spreads throughout the tree over a year, causing oranges to drop prematurely, contain aborted seeds or have a salty, bitter taste, compromising their use for juice. Root systems of infected groves often are poorly developed, and new root growth may be suppressed.
Infected trees get a “death sentence” after their sap is poisoned, even though symptoms might take several years to appear, said Michelle Cilia, assistant professor at Cornell University affiliate Boyce Thompson Institute for Plant Research, who has studied greening for two years.
By some estimates, the industry needs to plant more than 20 million trees in the next 10 years to restore production to pre-greening levels, said Michael W. Sparks, chief executive officer of Florida Citrus Mutual, which has more than 8,200 members.
While the disease is killing crops in other areas — including Brazil, the world’s top orange grower — it has caused the most damage in Florida, where urban sprawl and hurricane damage have helped shrink citrus groves to 501,396 acres (202,908 hectares), the lowest in 50 years.
High salinity in water can weaken the trees, leaving them unable to fight the bacterium, and strong winds from Caribbean storms carry insects farther into healthy groves. There also are more small farms in Florida, and many have been abandoned or poorly maintained, allowing the insect to proliferate.