EStimating the economic impact of an eventual introduction of huanglongbing (HLB) in the state of Bahia, Brazil

Abstract

Bahia is the second most important citrus region in Brazil, accounting for 5,5% of Brazilian production. 80% of the production comes from family based farms, which depend on this crop for economic support. Huanglongbing (HLB) was never recorded in Bahia, but is already spreading in three other citrus-producing states of the country, one of which borders the state of Bahia. Thus, this study aimed to estimate the potential economic impact resulting from an eventual introduction of HLB in Bahia. It was used the Gompertz and logistic models to estimate the disease progress under three scenarios. For the baseline scenario (A) the plant health agency efforts would prevent the HLB invasion. In scenario B, we assumed the disease introduction in citrus orchards and the absence of control measures, leading to the spread of HLB in the following years. In scenario C, after detection of the disease, the growers would adopt control measures: eradication of symptomatic hosts and suppression of insect vector populations. The costs of the disease control were calculated by considering the need for insecticide spraying, carrying out periodic inspections and eradication of symptomatic plants. The net present value (NPV) was used for comparing the scenarios. The results showed that, if the HLB is introduced in Bahia, the losses would be very significant in the following 20 years. If control and eradication procedures are not followed, losses in excess of US$ 890 million could occur.