Citrus Greening Disease the Effect on us Orange Crops

Something is happening in Florida’s orange groves these days and it could prove to be disastrous for Florida’s citrus industry possibly ending the state’s production of citrus fruits altogether. Florida citrus groves are now host to an unwelcome visitor called the citrus pysllid. Citrus pysllids are responsible for a disease known as Citrus Greening also known as Yellow Dragon disease because of the yellow pattern the disease leaves on the branches of infected trees looking very much like the pattern found on the back of a dragon. The tiny citrus pysllids spread Citrus Greening disease through their saliva when they suck on the branches of citrus trees. The insects aren’t the source of the bacteria for the disease but simply the spreaders of the disease. Only infected pysllids can spread the disease.

Citrus Greening disease may not present itself immediately. It might take as long as two years for the first symptoms to appear in an infected tree. Young infected trees may never bear fruit but wither and die off instead. Older infected trees will suffer from leaf yellowing or molting initially and then suffer from dieback. If a mature tree produces fruit it might appear misshapen and have a bitter taste, unmarketable at that point. In the final stages of the disease infected trees will develop the dragon pattern and simply stop producing any fruit and eventually they will die altogether. The disease will spread rapidly through a grove of trees. Once the insects are done feeding off of one tree they simply move to another. It is possible to have an entire grove infected all at once. Scientists who are studying the disease have recently discovered that it might be spread not only by the citrus pysllid but by the process of grafting.

There is no known cure for Citrus Greening. Residents of Florida and other citrus producing states are encouraged to report any suspected cases of Citrus Greening on their citrus trees, to their local agricultural extension so that these cases may be documented to help scientists further study the disease. Citrus Greening disease is not harmful to humans or animals. Because there is no known cure, Citrus Greening disease proves to be one of the most serious plant diseases worldwide and the most serious threat to citrus production. The state of Florida, as well as other citrus producing states, has placed their citrus plants under quarantine to prevent further spread of the disease.

Citrus Greening disease is known as Haunglongbing in eastern countries, where it originated and has been wreaking havoc for decades. Citrus crops in India, Vietnam and Southern China have been devastated by the disease. The citrus pysllid was first discovered in Florida in 1998 with the first signs of the disease showing up in 2005. At that time eight counties in the state were infected. Since then 31 counties in Florida are suffering some type of pysllid infestation. The state of Florida produces roughly 70% of the orange crop and 50% of the grapefruit crop in the United States amounting to over one billion dollars in sales annually. California is the second leading producer of citrus fruits with sales of all fruits, including lemons and limes totaling over 1.3 billion dollars annually. With the disease now prevalent throughout Florida the further spread of the disease could prove disastrous for the entire US economy.

The disease has already destroyed over 65,000 acres of trees in Florida. It has recently been discovered in Louisiana and Texas but it is unknown how widespread it is. The disease is yet to be detected in California but has recently been discovered in Mexico where it was thought not to have arrived. Unless a cure for the disease if found it will most certainly effect all US citrus producing states in time.