RESUMO
Aims@#Bacterial heart rot (BHR) disease caused by Erwinia chrysanthemi or the new nomenclature Dickeya zeae was identified as the lethal disease of pineapple and caused massive losses for the farmers due to non-satisfactory solutions. Thus, this study aims to understand the disease dissemination pattern and screen for tolerance pineapple variety prior to establishment of disease management strategies. @*Methodology and results@#Dissemination of BHR disease was observed visually in 2 study plots consisting 200 plants in each plot. Single plant inoculation of the pathogen was done in each plot namely Plot A at the edge and Plot B at the middle. Disease incidence was recorded at weekly interval for 12 weeks. The pattern of disease spreading in both plots was then mapped based on the results. Separately, 8 commercial pineapple varieties (Maspine, N36, MD2, Morris, Sarawak, Kristal, Gandul and Josapine) were screened for their resistance towards BHR. The varieties screening study was carried out using complete randomized block design. Overall, disease incidence (DI) was observed lower in plot A compared to Plot B. Percentage of DI in Plot A increased continuously from week 1 to 12, but in plot B the DI was stagnant starting from week 3 onwards. This study revealed that there is highly significant difference in percentage of infection between varieties tested. Josapine and MD2 were the most infected varieties based on lesion on plant. Both were found susceptible to BHR. Besides that, Chrystal Honey, Maspine and Sarawak varieties were less infected and classified as moderately resistance compared to other varieties. @*Conclusion, significance and impact of study@#Inoculum source was recognized as determinant factor for dissemination of BHR. Aggregation pattern was observed, and disease spreading was severe when disease started from the edge of the plot compared to in the middle. These findings will help farmers to choose the varieties of interest and plan for disease control measure based on first observed disease symptom in their field. This study is also important to researchers and plant breeders for varietal improvement in the future.