Status of Huanglongbing (HLB) outbreaks in Florida, California and Texas

Abstract

Nowhere in the U.S. is Huanglongbing (HLB) under adequate control due to the lack of effective tools to reduce spread of the vector, Diaphorina citri (Asian citrus psyllid), and transmission of the associated pathogen, Candidatus Liberibacter asiaticus, in the absence of disease resistance in commercial citrus varieties. In Florida, Asian citrus psyllid was well established by the time of HLB discovery and growers did not remove trees to eliminate inoculum, so there was no chance of controlling the epidemic. Based on the Florida experience, Texas proactively controlled the vector by implementing area-wide management and disease spread was slower than in Florida, however, they also did not remove infected trees. California controlled both ACP and tree inoculum and have delayed the development of an epidemic in the Central Valley. This situation is aided by topographic isolation from the Los Angeles basin where ACP and HLB are endemic and a climate distinctly different from other citrus growing regions in the U.S.

Development on Citrus medica infected with ‘Candidatus Liberibacter asiaticus’ has sex-specific and -nonspecific impacts on adult Diaphorina citri and its endosymbionts

“…The disease has since devastated the Florida citrus industry with consistent reductions year-after-year in citrus acreage and historically low citrus production [9,10]. The majority of citrus trees in Florida are now infected with CLas [11]. The California citrus industry may be on a similar path, as D. citri have been detected in most citrus-growing counties and the number of CLas-infected citrus trees continues to rise since CLas was first detected in the state in 2012 [11].…”

“…The majority of citrus trees in Florida are now infected with CLas [11]. The California citrus industry may be on a similar path, as D. citri have been detected in most citrus-growing counties and the number of CLas-infected citrus trees continues to rise since CLas was first detected in the state in 2012 [11]. The long period infected plants can remain asymptomatic, and the uneven pathogen distribution make timely identification and removal of diseased trees difficult [12][13][14].…”

“…The disease has since devastated the Florida citrus industry with consistent reductions year-after-year in citrus acreage and historically low citrus production [ 9 , 10 ]. The majority of citrus trees in Florida are now infected with CLas [ 11 ]. The California citrus industry may be on a similar path, as D .…”

Institutional approaches for plant health provision as a collective action problem

“…In the US, the NPPO provides oversight and funding, regulates the movement of plant material between states, and certifies diagnostic protocols (USDA-APHIS-PPQ, 2019). However, citrus health rules differ among states (Graham et al, 2020), and rule enforcement differs by county within states.…”

Global orange juice market: a 16-year summary and opportunities for creating value

“…In Brazil, citrus canker and also citrus variegated chlorosis (CVC) contribute to impact citrus production due to yield losses and increase in productions costs (Coletta Filho et al 2020). Finally, greening or HLB (huanglongbing) is currently the main threat to citrus production in the main citrus producing areas around the world including Brazil, USA, and China (Bassanezi et al 2020;Zhou 2020;Graham et al 2020).…”