International Workshop on Citrus Pests and Diseases, Indonesia. Terminal statement

The over-riding problem facing the expansion of citrus production in Southeast Asia was citrus vein phloem degeneration disease, or citrus greening. Its effec ts on productivity are dramatic; in Indonesia in 1987, yields of affected orchards we re only 8 tons per hectare, when healthy orchards were producing over 20 tons. Since 1987, the UNDP/FAO project, INS/84/007, `Research and Development for Citrus Rehabilitatio n', has concentrated on producing clean planting material, controlling the vector, and r emoving extraneous inoculum sources by sanitation. By its nature, this is a long-term p rogramme. Indonesia also participates in the UNDP/FAO regional project, RAS/86/022, `Contr ol of Citrus Greening Disease', under which two workshops had been held; funds not be ing available for the third, which was to be held in Indonesia in July in 1989, the current project was approved, to allow this conference to be mountedThe conference was held in Malang, from 4 to 14 July 1989. It provi ded a forum for the exchange of information, and allowed Indonesian scientists to expl ain the Indonesian Citrus Rehabilitation Programme to scientists from other countries, w ho might wish to use it as a framework for their own programmes. There was general recog nition that citrus rehabilitation in Indonesia was more advanced, and more technically sound , than in most of the other countries that participated. Other citrus diseases were also considered, and the need to determine the quarantine significance of a nematode, Radopholus, whi ch has been found in Tulungagung, East Java, was identified. Two problems with limes - witc hes' broom disease, reported from Oman, and a virulent strain of citrus canker, reported fr om the Maldives - also call for quarantine measuresHowever, the most serious new disease reported was the current epide mic in Africa of a devastating leaf mould, Phaeoramularia angolensis. It was recommend ed that the possibility of the continued rapid spread of this leaf spot disease be urgently raised with the Asia Pacific Plant Protection Commission, with the recommendation that a risk an alysis study of this and other citrus diseases be undertakenLegislation already existed in Indonesia to prevent the introduction of uncertified citrus material, but there are indications that the introduction of propagative material is not being effectively controlled. It was recommended that steps be taken to inform the travelling public of the risks, and to utilize the facilities of the Tlekung Research Station to safely import desirable materialWhile Indonesia has achieved considerable progress in citrus rehabil itation, a full understanding of greening disease, and practical field control measures, we re not yet available; an active research programme must therefore be maintained, and the i nformation necessary to prevent reinfestation must be made available for extension prior to the initial release of disease-free plants. Finally, it was noted that universities in Indo nesia are not currently contributing sufficiently to the national citrus research capacity, an d closer collaboration was required in order to better define research prioritie