| Author | Wijayalath, Hengodage Nirmalee Bhagya |
| Call Number | AIT Thesis no.AS-10-05 |
| Subject(s) | Tomatoes--Diseases and pests
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| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Agricultural Systems and Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AS-10-05 |
| Abstract | Bacterial wilt disease (BWD) caused by Ralstonia solanacearum E.M. Smith is a highly destructive and most widespread soil-borne disease mainly affecting crops in the Solanaceae family. There is no effective chemical or cultural control measures developed. Several microorganisms have been shown their promise for biological control of the disease. This study was conducted to re-assess the antagonistic potential of Candida ethanolica and Enterbacter cloacae and to explore the potential of their combination, different application methods, and soil modifications for the control of bacterial wilt disease in tomato. Two antagonists of Candida ethanolica and Enterobacter cloacae were evaluated individually and in combination under series of sucrose concentrations and media pH in in vitro against R. solanacearum. Both antagonists individually and in combination suppressed the growth of R. solanacearum to varying degrees. C. ethanolica, E. cloacae and mixed culture of two antagonists showed their highest inhibition at sucrose concentrations of 5%, 4% and 5.5% (w/v) and at media pH of 4-6, 6, 7 respectively. The antagonists were then evaluated under normal and modified soil conditions and three inoculation methods in a factorial experiment to control BWD in tomato in vivo. The disease suppression varied according to soil condition and inoculation method. Among the antagonists, C. ethanolica had the highest suppression of the disease. Application of antagonists by drenching was superior and followed by direct seed inoculation and root dipping. The control of the disease was increased when the soil was treated with sucrose concentration at 5 % (w/v) and pH adjusted to 6-6.5 range. These treatments reduced disease scores and improved plant height, biomass and yield of tomato. These findings can help the control of devastative bacterial wilt disease in Solanaceae crops and improve farmers’ incomes, and reduce or avoid the use of pesticides unconscientiously. |
| Year | 2010 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AS-10-05 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Aquatic Systems(AS) |
| Chairperson(s) | Ranamukhaarachchi, S. L. |
| Examination Committee(s) | Shipin, Oleg;Cochard, Roland |
| Scholarship Donor(s) | Ministry of Foreign Affairs, Norway |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2010 |