Journal of Citrus Pathology

Since its detection in Brazil in 2004, huanglongbin g (HLB) has caused expressive damage to the citrus belt in São Paulo, Minas Gerais and Paraná states. The disease incidence is higher in small groves mainly related to family farming. A risk analysis was performed in citrus regions in São Paulo and Minas Gerais with the objective of identifying the main factors associated with the introduction and spread of HLB in this farm profile. A structured questionnaire was applied comprising 27 closed questions with binary answers (0 or 1 as no or yes ) to 39 citrus growers along 12 municipalities. The regions were selected according to the HLB incidence and relevance of citrus family farming, and farms were assessed by non-probabilistic and convenience sampling. The Analytic Hierarchy Process (AHP) was used to prioritize and weigh specific criteria related to the factors evaluated. Based on the answers, each farm was classified into four risk classes: low (0 to 0.25), intermediate (0.26 to 0.50), high (0.51 to 0.75) and very high (0.76 to 1). The introduction risks into the sampled farms were very high due to the disease occurrence in neighboring areas. However, factors that most contributed to the spread risk within groves were different between the two regions evaluated. In South MG, lack of basic knowledge about HLB pathosystem and low use of control measures were major issues, whereas in East SP the spread was more related to grove age, productivity and density, and absence of area-wide management.