Citrus is one of the most important fruit crops worldwide consumed as fresh fruit and for processing. However, citrus systemic diseases of greening (HLB), and viruses such as Citrus tristeza closterovirus (CTV), Citrus tatter leaf cappilovirus (CTLV) and Citrus exocortis viroid (CEVd) have become serious constraints for the citrus industry in the Asian and Pacific (ASPAC) region in recent decades, causing considerable damage to fruit yield and quality. This is due to their systemic invasion and common spread through infected budwood, vegetatively propagated seedlings, and transmission by insect vector and by mechanical way. These major systemic diseases can only be effectively controlled by integrated measures of disease management such as: a) rapid diagnostic and indexing of virus strains; b) establishment of pathogen-free (PF) foundation and nursery system to prevent primary prevalence of the diseases; and c) health management of the PF-seedlings re-planted in terms of field sanitation and IPM of vector insects.
In the early 1990s, FFTC launched a technology transfer project to transfer Taiwan’s advanced technology to rehabilitate the devastated citrus industry in Vietnam. Since then, the project has been expanded to various Asian countries. More recently, PF-citrus foundation and nursery system has been established in Cambodia, with disease indexing techniques and the necessary equipment provided through this project. Health management of PF-seedlings re-planted in the orchards is envisioned to be a key technique for the successful rehabilitation of the citrus industry in Cambodia.
Other Southeast Asian countries such as Myanmar and Laos also need to adopt this integrated technology to rehabilitate their own citrus industry. Therefore, it is a matter of urgency to extend this technology-transfer project on the mass production of PF-citrus seedlings and their health management to the neighboring countries of Cambodia.
This technology transfer project shall aim to rehabilitate the citrus industry in Cambodia and its neighboring countries through the introduction of an integrated health management system to prevent the re-planted PF-seedlings from being re-infected by HLB and virus diseases. Mass production and extensive cultivation of PF-citrus seedlings will be promoted in Cambodia, Laos and Myanmar. An international workshop on improved health management of PF-citrus seedlings in the field will be organized in Cambodia in the second year of this two-year project.