Feb 04 2008
8. Abstracts
1. Arwiyanto, T. 2007. Survival of Fluorescent Pseudomonad in Organic Matrix of Coated Tobacco-Seed. Journal of Rural Development 7: 61-67
Strain Pf-20 of Pseudomonas putida and pseudomonad fluorescent isolate Pf-33 are the biological control agents of tobacco bacterial wilt caused by Ralstonia solanacearum. The method of delivery of the biological control agent, however, is inefficient and laboraious due to the need a lot of bacterial suspension for dipping the seedlings before transplanting. The use of cattle manure as a main substance for coating of tobacco seed was reported here. The cattle manure was sieved to 0.09 mm thenmixed with 0.1% CMC and suspension of Pf-20 and Pf-33. Prior coating, the seeds were surface sterilized with 1% sodium hypochloride for 30 seconds then air dried. The sterilized seeds were coated with the matrix until the size is 1.5-2.0 mm. The results indicated that fluorescent pseudomonad could survive longer in the coated seed when strain Pf-20 of P. putida and fluorescent pseudomonad isolate Pf-33 were used together in one formulation. Fluorescent pseudomonad could survive in the coated seed for 4 weeks. Seed germination, however, was not affected by coating with the materials stated above.
2. Arwiyanto, T., Maryudani, YMS, and A.E. Prasetyo. 2007. Charactherization and Activity Tests of Bacillus spp. As A Biological Control Agent of Lincat Disease on Temanggung Tobacco. Journal of Biological Researches 12: 93-98
Lincat disease of tobacco causing severe losses of the product. Control of the disease with any available measure unlikely giving enough control. A number of Bacillus spp isolates could suppressed the growth of pathogen in vitro and supressed the development of lincat disease in the field. This article report the charactheristics of six isolates of Bacillus spp (Ba-4, Ba-22, Ba-24, Ba-30, Ba-33, and Ba-41). These isolates proven could suppressed lincat disease in the field. Charactherization of the isolates include the morphological, physiological charactheristics, and pathogenicity against tobacco plant. The result indicated that the bacterial isolates were belong to the genus Bacillus with the following charactheristics. The bacteria were rod shaped, forming endospore, Gram positive, fermentative, positive reaction in katalase, oxydase, and Voges-Proskaeur tests. Negative results were obtained for Methyl Red test, hydrolysis of starch, gelatine, and casein. The present isolates could use citrate and several carbohydrates as carbon cources. Reduce nitrate to nitrite. The isolates could grow in the medium with high osmotic pressure, i.e. could grow in the medium with 7% NaCl. The present isolates grew well in the medium with pH of 4.5-10 and could grow in the temperature rabge of 10-50C. According to pathogenicity test, the present isolates were not belong to the plant pathogenic bacteria. The present isolates could suppressed the growth of Ralstonia solanacearum in vitro, and could reduce the egg number of Meloidogyne incognita. According to physiological charactheristics tested, it seem that isolates of Ba-4, Ba-24, Ba-30, and Ba-33, and Ba-41 having similar charactheristics with Bacillus cereus. The Ba-22 isolate, however, having similar charactheristics with B. licheniformis.
Keywords: tobacco, Bacillus, lincat disease, bacterial wilt