The latest Fundecitrus annual survey of the incidence of greening (huanglongbing/HLB) shows that the disease has spread from 38% in 2023 to 44% in 2024 throughout the citrus belt of São Paulo and Triângulo/Sudoeste Mineiro. This marks the seventh consecutive year of spread increase. 

According to Fundecitrus, approximately 90.36 million trees have been affected. In total, there are 203.74 million orange trees throughout the citrus park. 

Of the 12 regions in the citrus belt, five have an incidence above 60%, two have an incidence between 40 and 50%, three have an incidence between 15 and 25% and only two have an incidence below 5%.

The report states that the increase can be attributed to the highest historical population of the insect that transmits the disease, recorded in 2023, when the average capture per trap increased by 54% compared to 2022. 

Even with the increase in incidence, the 6.29% rise this year was significantly lower than the 13.66-point rise from 2022 to 2023. One of the possible factors related to the slowdown in the disease's progression from 2023 to 2024 might be due to higher-than-normal temperatures were higher than normal throughout the citrus belt. 

In the North and Northwest regions, where the disease was at a low incidence in 2023, a greater number of days were recorded in which maximum temperatures were above 35 °C.

Fundecitrus researcher Renato Bassanezi believes this may have discouraged the occurrence of new infections.

Other factors that might have helped the decrease include growers using disease management tools such as adoption of rotation of insecticides with different modes of action, reduction of the application interval and better spraying quality, applied with the same rigor in both young and mature groves.

The elimination of diseased plants in regions with low incidence of the disease was also maintained, and the elimination of severely affected orchards increased.

In addition, the selection of the planting area for new orchards, with the aim of finding places where disease pressure is low, favored the reduction of the incidence of the disease in the belt.

The regions with the highest level of spread in 2024 continue to be Limeira (79.38%), Brotas (77.06%), Porto Ferreira (71.77%), Duartina (63.93%) and Avaré (63.41%). The region with the highest increase in spread was Bebedouro (39.7%). The Altinópolis region remained in the group with a high incidence of greening (42.93%).

The regions of Matão (18.91%), São José do Rio Preto (17.57%) and Itapetininga (15.19%) remain in an intermediate range. Both Votuporanga (3.14%) and Triângulo Mineiro (0.11%) continue to have the lowest incidences.

However, in Votuporanga, a significant increase in the disease was observed in relation to the previous year (77.4%), while in Triângulo Mineiro a reduction in incidence was observed (68.6%).