Call Prefix : PR-T

Call Suffix : 1988

Call Cutter : D - PlPa 13

Location : SEARCA Library

Format : TD

Publisher : Universiti Pertanian Malaysia,

Publication Date : October 1988

Publication Place : Malaysia :

Summary : Bacterial wilt, caused by Pseudomonas solanacearum (Smith, 1986) Smith 1914, is disease of many crop plants. The lack of a truly effective method to control the disease, specially in the tropics, has been attributed to the many strains of the pathogen and lack of information on the ecology and variation in the pathogen population. This study was conducted to explain some aspects of the ecology and variation of the pathogen in Malaysia which will be useful in understanding the pathogen for the formulation of more effective control measures. A study of the distribution of bacterial wilt caused by P. solanacearum in Malaysia showed that the disease was widespread. It was observed in all areas (northern, central, and southern parts of Peninsular Malaysia, and East Malaysia) sampled. The disease occurred on many crop plants, weeds, and ornamentals. Two hundred and forty-three isolates of the pathogen was obtained from 25 plant species belonging to nine families. The pathogenicity of all isolates was confirmed on their respective hosts. The study indicated the need for strict quarantine measures presenting the introduction of exotic strains to the country and the need to reconfirm the status of the known pathogen hosts. Environmental conditions in Malaysia were conducive to the growth of the pathogen and the development of the disease, which were being observed throughout the year regardless of dry or wet weather conditions. The disease also occurred in many types of mineral (clayey, loamy, and sandy) and organic (peat and muck) soils. The type of hosts and their varietal susceptibility also played significant roles in determining the occurrence of the disease. Cultural characteristics P. solanacearum isolate on a tetrazolium medium and a medium containing 0.1 percent L-tryosine showed that isolates differed in colony size, fluidity and production of formazan and melanin. However, these could not be used to differentiate strains within race 1.