Source Year: 2000

Rubber (Hevea brasiliensis) plantations in Sri Lanka suffer from more than 20 diseases and six of them, namely white root disease (caused by Rigidoporus lignosus), Oidium leaf disease (O. heveae), Colletotrichum leaf disease (C. gloeosporioides [Glomerella cingulata]), Phytophthora leaf fall, Corynespora leaf fall (CLF) caused by Corynespora cassiicola, and black stripe will continue to be important during the next millennium. As chemical control alone may not be an acceptable strategy in the future, steps have already been taken to introduce an integrated approach to pest management with special emphasis on genetic resistance. There is confidence that this approach will minimise the incidence of the common diseases with minimum cost and environmental impact. However, Corynespora leaf fall, a relatively recent disease will remain a serious threat to the natural rubber industry not only in Sri Lanka but also in other rubber growing countries in Asia and Africa. During the last three decades more than half a dozen new pathogens have been discovered in Sri Lankan rubber plantations. Although the majority of these diseases are confined to the nurseries, field epidemics may occur in the future with the introduction of new high yielding genetic material. In view of this situation, the biology, epidemiology and management of these pathogens have been investigated and a special screening programme of potential clones against most of these diseases is in operation.