Citrus growers in in the U.S. state of Florida, the world’s largest orange grower after Brazil, fear for their future as citrus greening disease is having a devastating effect on the industry.
The United States Department of Agriculture (USDA) expects this season’s production in Florida will be the lowest in over two decades.
One of the U.S.’s largest citrus growers and Tropicana juice supplier, Consolidated Citrus in Florida, has lost hundreds of thousands of trees to the insect transmitted bacterial disease.
And on the remaining 27,000 acres many more are already infected, manager of horticultural services Mike Stewart said.
“This is a very serious, it’s an industry jeopardising disease,” Mr. Stewart said.
“We are probably looking at industry wide 70 percent or 80 percent infection rate. And we’ve got groves in our own company that are essentially 100% infected,” he added.
Overall production was down about 15 percent on the year last season, and it looks like this year will be turn out 14 percent less on the year, Mr Stewart said.
“One grove is down 35% from last season. So it’s having a devastating effect on us.”
Healthy citrus trees can stay productive for more than 50 years, but once infected, they can die within a few years.
“The fruit will become small and lopsided and develops a bitter, salty taste, so it’s unusable for human consumption,” Mr. Stewart said.
First detected in Florida in 2005, University of Florida economists estimate the disease cost the state US$4.5 billion and more than 8,000 jobs over five years up to 2011.
In its latest estimate, the USDA Agricultural Statistics Board expects to harvest 115 million boxes of oranges in the 2013/14 season, down 14% on the year. Only in the freeze affected 1989/90 season did the state produce fewer oranges. In 2003/04, the state still produced 242 million boxes.
Mr. Stewart said they now have several groves that are operating cash-flow negative.
And lower production is pushing up prices in the U.S. According to the Wall Street Journal, orange-juice futures jumped after the USDA lowered its production estimates last November.
Higher fruit prices cover some of the costs associated with controlling the disease, but Nielsen data published by the Florida Department of Citrus end of last year shows orange juice consumption is on the decline.
“These higher fruit prices are only going to accelerate or exacerbate this decline in consumption,” Mr. Stewart said.
Managing citrus greening
One of the greatest problems in controlling the disease is the it can take years for an infected tree to show any symptoms. But even before the disease can be detected, it can infect other trees.
The University of Florida’s Food and Agricultural Center recommends removing all trees that show symptoms immediately.
However, Mr. Stewart said this measure was no longer practical on their orchards.
They had sixty full-time employees that focused entirely on surveying trees and finding symptoms as early as possible, and then removing trees as quickly as possible.
“We ended up removing between 400,000 and 500,000 trees.”
“It took us perhaps a year to determine that we were already past the tipping point. We could not eradicate this disease, that was not a viable method.”
The company then focused on controlling the psyllid that spreads the disease through pesticides, as well as trying to strengthen the trees through nutritional programs and irrigation.
Research is presently focusing on better ways to control the spread of the disease, while some even think that developing a resistant tree would be the solution.
And while production is down, cost of production has doubled, Mr. Stewart said.
“We’ve gone from spraying two to three times per year to ten to twelve times per year.”
That could also be worrisome from a consumer perspective.
Mr. Stewart says testing by the government as well as the company they supply shows that the fruit is still well below maximum allowed contaminant levels.
But farmers are desperate for better solutions, to save costs as well as protect their own health.
“They are expensive, and we are on the front line, we have the most exposure to these pesticides so we are hoping to find other solutions,” Mr. Stewart said.
Instead of citrus, they are now growing other crops on affected areas, like sugar cane.
Spread of the disease
Citrus greening disease was first detected in China in the early 1900s and has since spread to many other regions including southeast Asia, the Indian subcontinent, eastern and southern Africa, Brazil, Mexico and the US sunshine state
It is not present in Australia, but given the difficulty of controlling it, keeping it out permanently could prove very difficult.
“With international trade and tourism, it may be inevitable,” Mr. Stewart said.
However, having travelled to Australia himself, he found the country’s import controls more stringent than in the U.S.
“I think they have a good chance of keeping this disease out for a long time,” he said.