Ecology And Environment

Citrus Greening Disease

Danielle Dusold's image for:
"Citrus Greening Disease"
Image by: 

Something is leaving a bitter taste in citrus farmer's mouths in Florida, and it's not a particularly bitter grapefruit. Small psyllids are bringing an unwelcome visitor to citrus crops and it could lead to the collapse of the citrus industry, particularly in Florida. That unwelcome visitor is CandidatusLiberibacters, a gram-negative bacterium that has already caused problems in Brazil, China, India, and other citrus producing regions or the world and its problems can be devastating to a citrus crop.

Psyllids are the host organism that carries this bacterium from tree to tree, spreading the disease that has no cure. Once the psyllid has carried Candidatus liberibacters to a citrus bearing tree, the bacterium makes its way into the tree, taking up to a year before the signs begin to show. The leaves begin to droop and turn yellowish. Fruit begins to drop from the tree at an unusual rate. Upon inspection of the fruit, the farmer finds that it is small, misshapen, and has a green end on it, even though it's supposed to be mature. When the farmer looks inside of the fruit, he notices that the seed is brown and truncated. The fruit itself has a bitter taste and is not marketable to anyone.

The occurrence of citrus greening disease was first noticed in Florida in 2005, although the particular organism that plays as its host was found in Florida 1998. It occasionally has popped up in other regions in the USA, as well as Mexico, but in 2005, Florida saw devastation they thought was only possible by hurricanes. Trees were dying at amazing rates and no one knew what to do. Citrus prices skyrocketed in light of the crops being threatened by a disease that proves to have only one end result: death of the tree. As of right now, the only method of prevention is trying to prevent the psyllids from spreading the bacterium, which means restricting the imports of citrus from foreign countries, including plants, cutting down trees that are infected to prevent spread, and constant vigilance in the orchards, where farmers work together to identify these pesky vectors and inform government agencies of their presence.

There are no resistant citrus tree species. There is no spray that will fix this situation. Right now, the most important thing for anyone to do is to learn how to identify the psyllids that are the vector of this disease and be on the lookout for citrus trees that contract the disease by looking for the telltale signs and removing this tree as soon as possible to decrease the risk of spreading the disease. What will happen to US Citrus crops? It's truly too soon to tell. Unless scientists can find a treatment, this disease could devastate US Citrus crops and destroy Florida's economic gem. The race is on, but no one can tell if this disease can be stopped in time.

More about this author: Danielle Dusold

From Around the Web