Incurable Bacteria Threatens Citrus Groves – Insects Spread ‘Greening’ Disease On Trees

By: John Lester
01/19/2011 01:58 PM ET

Incurable Bacteria Threatens Citrus Groves — Big problem. Citrus Groves in Florida are vulnerable to an incurable bacteria that’s spreading fast. It’s becoming such a big problem that Florida farmers have lost much of their crop.

Citrus greening has destroyed groves in the U.S., Brazil, Asia and Africa. Detected in Florida in 2005, it leaves fruit sour, malformed and unusable. Eventually, it kills the tree.

The disease has been particularly devastating because it takes years for citrus trees to reach peak production, and the disease targets young trees, making it difficult for growers to replace those that have been lost.

“It’s probably is one of the biggest negative impacts in Florida today, short of the housing collapse,” said Louis Schacht, a Vero Beach farmer whose family has grown oranges for 60 years.

Trees don’t pass the bacteria to each other. Instead, greening — also known as yellow dragon disease, HIB or, in Chinese, Huanglongbing — is spread by insects. There is no cure.

Hundreds of researchers from more than a dozen countries converged on Orlando last week to talk about the disease and hear the latest research. They found hope in one announcement: A University of Florida-led group of international scientists has assembled the genome sequences for two citrus varieties — sweet orange and Clementine mandarin — in an effort to determine why trees are so susceptible to greening. Eventually, they hope to engineer varieties that aren’t.

“There is nothing we have today that is effective against the bacteria,” said Dan Gunter, chief operating officer of the Citrus Research and Development Foundation Inc., which funds research on greening and other citrus issues.