Temporal changes in occurrence of stem-end rot in mango fruit clusters, habitat distribution and conidial dispersal of the causal pathogen, and effect of removal of dead-branch residue on cultural control against stem-end rot in greenhouses
2019
Takushi, T. (Okinawa Prefectural Agricultural Research Center Miyakojima Branch, Miyakojima, Okinawa (Japan)) | Higa, A. | Iyama, K. | Ishimine, H. | Tedokon, T.
To estimate the infection source of mango stem-end rot, we investigated the temporal changes in the occurrence of stem-end rot of mango fruit clusters. We also examined the habitat distribution and conidial dispersal of the causal fungus, Lasiodiplodia theobromae from lesions in diseased fruit clusters under greenhouse cultivation. Occurrence of stem-end rot in fruit clusters increased after anthesis in March and peaked during the harvest period in July. Conidial dispersal fluctuated markedly from May to July, with vigorous dispersal occurring from mid-to late June. Lasiodiplodia theobromae was isolated at high rates from flowers, peduncles, fruit-bearing shoots, and fruiting mother shoots, indicating extensive latent infection in a diseased field. We assumed that the main infection sources of this disease are infected fruit clusters and conidia from lesions on infected fruit clusters. We subsequently investigated the efficacy of removing dead branch residues in greenhouses to prevent the spread of disease. We found that occurrence of the disease in fruit clusters was significantly lower for branch-removal plots relative to the untreated control. Specifically, incidence of the disease in branch-removal plots was reduced to 31.1-56.0% of that in the untreated control during anthesis and 32.5-38.8% during the harvest period.
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