also require more intensive management if more growers are involved. Such areas would allow a small set of management strategies to be performed in an effective and timely fashion and their results to be evaluated. In addition, management strategies can be evaluated and compared among Citrus Health Management Areas with similar or different HLB incidences. Citrus Health Management Areas would be organized and operated by local growers and grower organizations with advice from an oversight organization (see Recommendation O-2). Funding for mitigation practices (i.e. insecticide applications and infected tree identification and removal) could come through grower taxes or possibly from government sources and be administered by the Florida Citrus Production Research Advisory Council (FCPRAC), the Florida Department of Citrus (FDOC) or the Citrus Research and Development Foundation (CRDF). The management areas would be charged with facilitating HLB mitigation and dealing with other threats to citrus production and quality within the area. The manager of a Citrus Health Management Areas should be empowered to enforce best management practices within the area, including cleaning-up abandoned or poorly maintained HLB-infected orchards, designing and implementing compensation plans, coordinating area-wide psyllid sprays, and reducing risk from infected urban citrus.
In some areas where incidence is low, aggressive tree removal and psyllid control will be the practice of choice. However, in areas where incidence is very high and tree removal is not feasible, only badly declining trees or blocks would be removed and those blocks with enough healthy trees to be profitable would be maintained for a few years. Such blocks would still need aggressive psyllid control to minimize spread to healthy trees or to less affected areas. In other areas, it may be necessary to remove as much citrus as possible so that new plantings can be made without the danger of being surrounded by abundant sources of inoculum. Removal of badly affected groves can result in loss of the agricultural tax exemption. Groves would need to be converted to pasture or planted with forest trees to maintain that exemption. Changes in tax law could be helpful in eliminating this impediment to removal of affected groves.
Area-wide insect control strategies should utilize “window” strategies where only certain classes of insecticides are permitted during specific periods to minimize the development of resistance (see Recommendation NI-1). Programs designed to train, and incentives to retain, personnel should be developed to ensure continuity of personnel familiar with needs of that region.
Research has shown that low volume aerial applications are the most convenient way to achieve Asian citrus psyllid (ACP) control in the thousands of acres of a Citrus Health Management Area. However, while aerial application for other arthropods requiring management within the area (e.g. mites) may be combined with ACP insecticides, possible effects on non-target natural enemies and other pest species must be taken into account. Care and knowledge are needed to determine which insecticides can be effectively used in low volume aerial applicators.
Control of ACP in organic orchards is challenging since there are no systemic products approved by the Organic Materials Review Institute (OMRI). This leaves products such as JMS Stylet oils and products based on neem and chrysanthemum as the only choices, and these are not likely to result in the effective long-lasting control needed to mitigate HLB. Any failure to control ACP and HLB in an orchard has direct negative impacts on surrounding orchards.