Paraná advises against the advance of greening

Seab, Adapar and IDR-Paraná issued a technical note with guidelines for the prevention and control of HLB, also called "greening", in the state (link at the end of this article).

It is the main disease that affects citrus plantations around the world, and can have a strong impact on the economy of producing regions. Without exaggeration, Huanglongbing (HLB) has the potential to make citrus farming unviable in Paraná and even in Brazil”, warns the research manager at IDR-Paraná, Pedro Martins Auler.

The disease is caused by bacteria Candidatus Liberibacter asiaticus, and its cycle also involves a small insect, the Asian citrus psyllid (diaphorina citri), which acquires the microorganism by sucking the sap from diseased plants and disseminates it in orchards when it feeds on healthy trees.

Identification of the disease can be done by simply observing the symptoms, but confirmation requires a laboratory test, called polymerase chain reaction, or PCR.

Infected plants initially present leaves with yellow spots (or entirely yellow, if they are new) on just one or a few branches, a condition that can progress to the entire crown of the plant. If there is production, there will be premature fruit drop, which will be small, asymmetrical and greener, with aborted seeds, reduced sugar content and high acidity.

There is no treatment for HLB and its control must be preventive. The recommendation is to apply insecticides to control the psyllid population, the insect vector of the bacteria, and systematically eliminate diseased plants, including in home-grown crops in backyards and leisure farms.

“Preventative management also includes the implementation of windbreaks, always using healthy seedlings of good origin for the installation of new orchards and planting density”, adds Auler.

Around 29 thousand hectares of citrus fruits are cultivated in Paraná, which, according to preliminary data from Seab's Deral (Department of Rural Economy), yielded 842,4 thousand tons of fruit in the 2022 harvest.

The segment involves more than 600 citrus growers, with an average area of ​​30 hectares, and is present in around 100 municipalities in Paraná. The State is the third largest national producer, behind São Paulo and Minas Gerais.

Two centers stand out in the production of citrus fruits in Paraná: oranges in the North and Northwest; and tangerines in Vale do Ribeira and the Metropolitan Region of Curitiba.

The production of oranges in the North and Northwest regions is mainly intended to obtain frozen concentrated juice (FCOJ) and ready-to-drink, processed in four larger industrial units. It also supplies more than a dozen sorting companies focused on fruits for the fresh market.

“There is a production chain established in these regions, generating jobs, income and great economic impact in Paranavaí, Alto Paraná, Guairaçá, Terra Rica, Atalaia, São João do Caiuá, Nova Esperança, Cruzeiro do Oeste, Altônia, Uraí, Nova América da Colina and other municipalities in this belt”, concludes the director.