Something has been killing Florida's citrus industry. Its name is HLB Greening.
Florida is the world’s third-largest citrus grower, behind Brazil and China, and we are the number one producer in the United States. Still, for the past decade, Florida’s citrus industry has been dwindling.
The citrus industry seems to always be under attack from pests or diseases, such as Tristeza and canker. Even the weather has tried to destroy the industry through hurricanes and freezes, yet it prevails. But this latest disease has caused more damage to citrus crops around the world than any of the other challenges. Its name is HLB greening.
Greening Disease History
The citrus greening disease is created and transmitted from an Asian Citrus Psyllid. The two primary forms are the heat-tolerant and the heat-sensitive, though three different types have been found. The Chinese first discovered and wrote about this disease in 1929.
The next reports of it came in 1947 in South Africa, but it didn’t become a concern to Americans until 2005, when it started to spread rapidly. Within a few years, almost the entire state was infected. Sixteen years later, we still don’t have answers for a cure.
The first confirmed sighting of the Psyllid in Florida was in 1997 when the state was picking more than 200 million fruit boxes each year. By the time greening started to affect the state seriously, Florida was producing 150 million boxes in 2005, and today we are picking less than 45 million boxes statewide.
How Does Greening Disease Work?
Here’s how the disease works. The Asian psyllid flies through the grove, landing on the leaves and feeding on the leaves and stems. The psyllids transfer bacteria to the tree, and once infected, the tree starts to die. The leaf’s veins will turn yellow, and their edges will wilt. The disease attacks the tree’s nutrition and circulation system.
The first signs are in the leaf, but as the years go on and the tree begins to produce smaller and fewer fruit. It also causes fruit to fall off the tree too early, so even if the fruit was going to be pickable, it falls to the ground and dies. So not only does the farmer have a 50%- 50% chance of having a good fruit but also a 50%-50 % chance the fruit will fall off the infected citrus tree.
So what is being done to stop this?
Millions of citrus acres have been lost to greening, thousands of jobs have been lost, and billions of state income have been lost. Millions of dollars have been spent both by the government and private citizens and companies on research for a cure, but none have been found to date.
Florida’s citrus growers have resorted to creating concoctions of chemicals, pesticides, herbicides, and insecticides. More time, energy, and money have to be devoted to each individual tree if a grower wants a good harvest of Florida oranges and other citrus fruits. The expenses have doubled just to keep the tree alive.
Twenty years ago, grove management costs would have cost $800 per acre, but today that same grove might cost $2,800 to $3000 per acre. Those costs go up even higher if you want to keep the trees safe under shade cloth.
The success rate of keeping greening out of a grove planted under shade cloth is astonishing. Shade cloth is a thin screen that covers the entire grove, letting sunlight in but keeping it safe from greening.
Growers under shade cloth often plant very high density dwarfed trees with thin rows between them to have very high yields with low maintenance. But this way of growing is not cost-effective for large-scale growers as it could cost up to $90,000 an acre to put the shade cloth up and get the grove growing.
Most growers prefer the conventional route of adding more pesticides and nutrients to the tree, but this still does not save the tree. It only slows the tree’s death.
The University of Florida has developed several new rootstocks that have proven to be greening tolerant but not resistant. Meaning the roots provide a base that has better protection against the Psyllids but is still affected by the disease. This has been done by genetically modifying the citrus plant’s DNA with specific genes from spinach and mustard plants, which does not impact the taste of the fruit.
Some growers have used reflective metallic-like mulch, which, when the sun reflects off of it, blinds the psyllids making it harder for them to find the tree.
We are still years away from having a solution or cure, so what does this mean for the industry?
Growers are spending more money to produce fewer and fewer crops. The state’s overall production levels continue to dwindle to all-time low records. Every day trees are dying, and many wonder if the industry will ever make a full comeback from this disease. That is why orange juice’s price has increased and will continue to grow as the world is plagued with a seemingly incurable disease.