Brazil, US Identify Molecule to Help Fight Citrus Greening

10 December, 2017

Researchers have identified a molecule that attracts an insect which carries citrus greening disease.

This development is expected to help farmers control a disease that has destroyed citrus trees in areas of Brazil and the United States.

The discovery is the result of six years of research on Diaphorina citri, an insect that is the vector of citrus greening disease.

FILE - A box of tangerines is seen at a packaging warehouse of Hoja Redonda plantation in Chincha, Peru, Sept. 3, 2015.
FILE - A box of tangerines is seen at a packaging warehouse of Hoja Redonda plantation in Chincha, Peru, Sept. 3, 2015.

The molecule was identified by the research center Fundo de Defesa da Citricultura, or Fundecitrus. The effort was carried out in partnership with the University of California, Davis and the University of Sao Paulo's Agricultural College.

The next step will be to synthesize a chemical substance from the molecule. Then, researchers will create a product that will work as a trap to attract and stop the insect. Scientists hope to reduce the spread of citrus greening disease. The disease is blamed for the destruction of almost half of Brazil's current orange tree area since 2005.

Juliano Ayres is the general manager at Fundecitrus. He says, while these measures will not cure greening disease, in his words, "it will allow us to work in an intelligent and assertive way against the insect."

The first commercial product should be available to farmers in a year, said Walter Leal, a Brazilian researcher representing UC Davis.

Fundecitrus said Brazil's main citrus producing areas have almost 175 million trees planted on about 415,000 hectares. It is estimated that 32 million trees are infected.

There is no cure for citrus greening disease.

The United States Department of Agriculture (USDA) says it is one of the most serious citrus plant diseases in the world. Infected trees produce fruit that is green, misshapen and bitter. This makes them unsuitable for sale as fresh fruit or for juice.

The USDA says most infected trees die within a few years.

I'm Jonathan Evans.

Reuters first reported this story. Jonathan Evans adapted it for Learning English. Mario Ritter was the editor.


Words in this Story

assertive adj. confident in behavior or style

bitter adj. having a strong and often unpleasant flavor that is the opposite of sweet

citrus n. a juicy fruit such as an orange, grapefruit, or lemon that has a thick skin and that comes from a tree or shrub that grows in warm areas

synthesizev. to make something from simpler substances through a chemical process

vector – n. an insect, animal, etc., that carries germs that cause disease