Huanglongbing or citrus greening, is a threat to the citrus industry worldwide and was reported in the central region of São Paulo state (SPS) in Brazil in 2004. The disease then spread quickly throughout SPS, which required the citrus industry to adapt rapidly to prevent the devastating impacts on production.
According to a survey conducted by Fundecitrus in 2020, 20.87 percent of the orange trees in SPS and the west–southwest regions of Minas Gerais state showed symptoms of HLB. This compares favorably with other countries, where disease incidence is much higher. The difference may be partially explained by the previous experience of Brazilian citrus growers with citrus variegated chlorosis (CVC), a disease caused by the bacterium Xylella fastidiosa and spread by leafhoppers.
In SPS, ACP monitoring is considered an important component of HLB management; use of yellow sticky traps is the primary method. Traps are mostly set on orchard borders, particularly along property perimeters, and are checked weekly and replaced biweekly. The detection of a single psyllid is sufficient to trigger ACP control measures.
In SPS, the establishment of coordinated regional psyllid management has proved essential for successful HLB containment. In 2011, Fundecitrus developed the Psyllid Alert System (PAS) to coordinate simultaneous, area-wide insecticide application based on the regional ACP population and citrus vegetative stage.
Currently, PAS is available for 12 regions of SPS and the west-southwest of Minas Gerais state, with approximately 31,700 yellow sticky traps (92 percent from growers and 8 percent from Fundecitrus) distributed in 1,498 orchards, for a total monitored area of 280,774 hectares.
Source: citrusindustry.net