Pathogenic variability in isolates of Phytophthora species causing black pod disease of cocoa in India in relation to host reaction
Loading...
Date
2007-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Pathogenic variability in three species of Phytophthora causing black pod disease of cocoa was studied on detached pods of 20 cocoa accessions. Mycelial disks were used to inoculate fully developed but unripe pods. Lesion size (cm1), mycelial growth and sporulation on lesion surfaces were recorded after seven days after inoculation. The three species of Phytophthora exhibited significant difference in lesion area between species. P. palmivora produced larger lesion area, higher amount of aerial mycelium and sporulation on all cocoa accessions. P. capsici and P. citrophthora failed to sporulate on pods of all accessions. The cocoa accessions exhibited wide variations in degree of resistance to (Phytophthora species. The cocoa accessions C44 and C79 were found to be highly tolerant to all three species of Phytophthora where as Landas 346 was highly susceptible. Thus, the study not only helped in determining the variability among the Phytophthpora species but also in identifying in tolerant and highly susceptible cultivars.
Description
Keywords
Cocoa, Phytophthora spp., pathogenic variability, host reaction
Citation
11th international cocoa research conference 1993