A study of bacterial heart rot disease in pineapple at Johor / Hakimi Mansuri and Zafri Ab Wahab

Pineapple (Ananas cotnosus L. Merr) is considered as economically important horticultural crop with great health benefits and encouraging market potential in the global market for foreign exchange earnings which in tum brings higher income for the farmers. However, production of pineapple affected by the serious damage caused by the Erwinia species, particularly bacterial heart rot disease caused by Dickeya zeae previously known as Erwinia chrysarithemi. Known as "major" disease in pineapple cultivation. In this study, data of the incidence and severity from different field recorded. Result showed that there are significant difference (p < 0.05) percentage (%) incidence and severity between each field. The data are based on field A 19.20%, 15.00%, field B 19.20%. 23.60%. and field C 20.00%, 18.80% respectively. However, all field recorded low percentage (%) of disease incidence and disease severity which are below than 40%. The bacterial heart rot disease was isolated in order to identify and verify its characteristic on NA medium after two days incubation period. After two days, the bacteria of becterial heart rot disease has been observed which was can be detected through the appearance of light white, circular, flat and smooth. The result of observation was obtained by using the microscope in order to observe the microscopic characteristics of the bacteria. The pathogenicity test was carried out by using the injection fruit method to test the Erwinia chrysanthemi isolate on the fruits of the pineapple which given the positive result for the infection development. The pathogenicity tests proved by using the Koch's Postulates method that isolated Erwinia chrysanthemi was capable to infecting local susceptible pineapple plants in Johor.