The role of Colletotrichum species on the Colletotrichum leaf disease of Hevea brasiliensis - A preliminary study

Abstract

Colletotrichum Leaf Disease (CLD) is considered as one of the major causes for the decline in yields of rubber in the Asian continent. Since early 1900's the pathogen Colletotrichum gloeosporioides has been considered as the causative agent of this disease in all rubber-growing countries in the world. However, observations of a recent survey in Sri Lanka revealed that the fungus Colletotrichum acutatum also plays a significant role in the development of CLD in rubber plantations. Therefore, a complete understanding of the involvement of the two Colletotrichum species in causing CLD is necessary. In order to assess the effect of the two species separately and in combination, an in-vitro investigation was carried out using young rubber leaves. The results suggest that C. acutatum is the major pathogen causing larger lesions. The results also showed that the two fungi can be synergistic in causing CLD if C. acutatum is introduced before C. gloeosporioides.