Greening: SP government reinforces actions to combat the disease

Greening puts orange orchards in several countries at risk; citrus industry in São Paulo exports US$ 2 billion per year and is the largest in the country

10.11.2023 | 16:27 (UTC -3)
Secretariat of Agriculture
Photo: Disclosure
Photo: Disclosure

The disease that most threatens orange production worldwide, greening affects all types of citrus plants and has no cure. This plague is caused by a bacteria and spread by an insect called a psyllid. In other words, once contaminated, it is not possible to eliminate the bacteria from the plant, which in turn serves as a means for the psyllid to infect other species in the orchard. In view of this, the Government of São Paulo treats the control of greening as a priority and is adopting a series of actions to control the pest. 

Last month, a meeting to address the issue was held between governor Tarcísio de Freitas, the technical staff of the Secretariat of Agriculture and Supply and citrus industry leaders in the state. State management also recently launched a reporting channel for producers who identify the pest in their orchards.

“There is a high rate of development of the pest mainly in abandoned orchards and home orchards. We often have an orange tree or any other citrus tree at the back of the yard and, sometimes, this tree is a source of disease and contamination for other orchards, especially commercial ones”, says the coordinator of the Sectoral and Thematic Chambers from the Secretariat of Agriculture and Supply, José Carlos de Faria Jr.

According to the Citrus Defense Fund, Fundecitrus, a private association maintained by citrus growers and juice industries in the state of São Paulo, although greening was first found in Asia more than 100 years ago, it was identified in Brazil only 2004. Today, the disease is present in all citrus growing regions of São Paulo and in orchards in Minas Gerais and Paraná, as well as countries in South America and the United States.

Controlling greening is extremely important for agribusiness in São Paulo, which is the largest producer of oranges in the country. According to Fundeciturs, São Paulo's citrus industry exports US$2 billion per year. There are around 9.600 properties that generate 200 jobs in the state.

Control and features

To prevent the pest from spreading, producers must control the psyllid. This control can be done through the rotation of agricultural pesticides used, for example. Another need is the eradication of plants contaminated with the bacteria for up to eight years. 

When affected by greening, younger orange trees are unable to produce fruit. Adult trees suffer premature fruit loss and end up withering over time.

The first symptom of greening is the appearance of yellowed leaves with irregular spots, without symmetry between the two halves. Affected leaves also tend to fall and give way to new, small, upright shoots. In some cases, the leaf vein becomes thicker and lighter, and may also acquire a rough texture.

Oranges from stems infected by the bacteria do not ripen normally and become a light green, mottled color, deformed and small, falling off the stem prematurely.

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