Operation against greening begins in Northwest Paraná

The city government of Paranavaí, in the northwest of Paraná, began cutting down all citrus plants and myrtle, an ornamental species, in the city's urban perimeter this Monday (27). The objective is to eliminate host plants for the psyllid that transmits greening, recognized worldwide as the most aggressive disease for citrus farming.

Agents from the Paraná Agricultural Defense Agency (ADAPAR) provide support to municipal employees, with the aim of acting in the event of resistance from landowners. Decree 4.502/2023, with validity extended in December 2024, which declared a state of phytosanitary emergency in the State, gives the agency the power to inspect and ensure the eradication of unmanaged host plants for the psyllid wherever they are being cultivated and to fine resistant landowners, if necessary.

“Our team is engaged, and they are working indefinitely to, among other equally important tasks, carry out greening control actions in the 29 municipalities within the Adapar Regional in Paranavaí”, stated the president of Adapar, Otamir Cesar Martins, when positioning himself in favor of the action.

The operation began in the Sumaré District, one of the most populous in the municipality. Municipal agents from the Department of Agriculture, Endemic Control, Health Department and Municipal Guard, who also have support from the private sector, are visiting all the houses in an attempt to raise awareness among the owners to cooperate in carrying out the cuts, given the importance of the action.

The removed plants are being crushed and disposed of in a suitable location by the Municipal Department of the Environment.

It is estimated that urban areas have just over 3 citrus and myrtle trees. Their cutting aims to preserve the large area of ​​commercial citrus production, which is one of the city's main economic activities. After Sumaré, the teams will do the same work in other neighborhoods, giving preference to the peripheral regions closest to the commercial production areas. It is estimated that at least 5 people are employed in this production chain in Paranavaí.

Task force

Adapar, together with other public entities, industries and citrus producers, has been developing activities in a more organized manner and as a task force since 2023 to combat the disease and its vector, the psyllid. Diaphorina citri Kuwayama. Many plants have since been eliminated, including areas of commercial production, where management continues.

The current operation began to be planned last week during a meeting between Mayor Mauricio Gehlen and municipal secretaries, Adapar inspectors and representatives of the local citrus industry.

The regional manager of Adapar in the Paranavaí Nucleus, Alisson Santos Barroso, spoke with municipal technicians in the morning and provided information on how to proceed. “What is needed is awareness first. Naturally, most residents are already aware of the need for action. Only in cases of resistance do we begin to address the situation from the perspective of inspection,” he said. “The owner has the opportunity to have the plant eliminated by the team that is doing the work. If he does not agree at this time, he will have to do so later, at his own expense, in accordance with the legislation.”

No cure

There is currently no known cure for greening disease. Eradication of infected plants and good psyllid control practices are the recommended alternatives. Greening or HLB (Huanglongbing) is an important pest due to its severity, rapid spread and difficulty in controlling.

The disease seriously affects citrus plants, mainly due to premature fruit drop, which results in reduced production and can lead to early death. In addition, the fruits become smaller, deformed, and may have aborted seeds, reduced sugars and high acidity, which depreciates their flavor, reducing their quality and commercial value, both for fresh consumption and for industrial processing.

Good habits 

One of the practices to prevent the disease is to plant healthy, high-quality seedlings from registered nurseries. In Paraná, the sale of plants by street vendors is prohibited. Preventive management also includes the use of windbreaks and planting density. Psyllid control can also be done with tamarixia radiata, a wasp created in a laboratory, including the one at IDR-Paraná, whose eggs serve as food for nymphs, eliminating them.  

Good fertilization, quality irrigation and plant cover are also good allies for the rapid development of the plant, reducing exposure to the insect, since transmission is more common in shoots than in adult leaves.

Spraying at intervals that respect agronomic guidelines is important, with the use of chemical and biological insecticides with proven efficiency. It is also recommended to rotate insecticides, which must be applied using all techniques that eliminate the possibility of drift.