Effect of Microbial Antagonists on the Development Of Bacterial Wilt on Tomato
Bacterial wilt caused by Ralstonia solanacearum is the major constraint to the production of tomato in Malaysia. In this study, the effect of application methods of biological control agents to control bacterial wilt of MT11, a moderately resistant variety of tomato was evaluated under greenhous...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English English |
| Published: |
2003
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/10636/1/FP_2003_5.pdf http://psasir.upm.edu.my/id/eprint/10636/ |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Bacterial wilt caused by Ralstonia solanacearum is the major
constraint to the production of tomato in Malaysia. In this study, the effect of
application methods of biological control agents to control bacterial wilt of
MT11, a moderately resistant variety of tomato was evaluated under
greenhouse and field condition. Six antagonistic strains of Pseudomonas
aeruginosa showed in vitro antagonism towards R. solanacearum. Seed biopriming
with these strains of P. aeruginosa either individually or in
combination increased the percentage of seed germination. Whereas,
biomass of plants was increased only after seeds were bio-primed with the
combined strain. Combination of strains KT8+ 72PTT was used as seeds bioprime
agent in greenhouse and field experiments.
Penicillium sp. showed in vitro antagonism towards R. solanacearum
Greenhouse experiment also showed that the antagonist could reduce the
incidence of bacterial wilt on MT11. An experiment was carried out on the
effect of the application methods and levels of concentration of the antagonist on the biomass of plants. Results showed that soil incorporated with
Penicillium sp. just before transplanting Significantly reduced the biomass of
top part of six true leaves seedlings. Direct drenching of antagonist also
Significantly reduced the biomass of four-week-old seedlings, either at high or
low concentration. However, no Significant reduction was observed in the
biomass of root system and dry weight of top when the antagonist was
incorporated into soil one week prior to transplanting.
Two greenhouse trials were conducted to evaluate the integrated
control using combination of bacterial and fungal antagonist and calcium
nitrate, on MT11. Both the experiments showed reduced incidence of
bacterial wilt on plants, which were treated with the integrated control
measures. Combined treatment of seed bio-priming and carrier application of
Penicillium sp. at high concentration recorded the lowest Disease Severity
Index of bacterial wilt in the second greenhouse trial. Carrier application of
Penicillium sp. provided better protection to plants compared to direct
drenching regardless of inoculum concentration. |
|---|