Application of actinomycetes and common fungicides for controlling the tree brown root rot disease
Date Issued
2016
Date
2016
Author(s)
Li, Wei-Chen
Abstract
Brown root rot disease caused by Phellinus noxius is a common root disease distributed in tropical and subtropical regions of Asia, Africa, Oceania and Australia. In recent years, wilting and decline found on some important fruit and urban trees in Taiwan were attributed to this brown root rot disease. At present, the main method to control the brown root rot disease is chemical control. it was a reported that tridemorph, penconazole and triadimenol could inhibit the mycelial growth of Phellinus noxius in foreign country. Taiwan Agricultural Research Institute also reported that 4-4 Bordeaux mixture, propiconazole, triadimefon, tridemorph, prochloraz, mepronil, benthiazole, iprodione and pyriferox+40% quinolate showed good effect to inhibit mycelial growth of pathogen. For biological control, some actinomycetes and Trichoderma spp. from rhizosphere were reported to inhibit mycelial growth of Phellinus noxius, but there was no further application test. In the study, therefore, we isolated 20 strains of actinomycetes showing ability to antagonize Phellinus noxius from Miaoli, Taipei and Hualien. Two strains Br-br and Br-wh with another strain YU01 isolated from Yuli, Hualien were selected to process the simulated stem section test. And depends on the database of NCBI, strains BR-br and BR-wh belong to genus Streptomyces. The dry weight loss rate of inoculated stem section and the survival rate of P. noxius in stem section were used to estimate the antagonistic effect of three actinomycete strains. Results show that the dry weight loss rate of treated stem section are lower than the control in both growth chamber and field test after the treatment of actinomycetes liquid culture. The survival rate of pathogen in treated stem section is also lower than the control one in growth chamber but no significant differences in the field test. In chemical control, we test six fungicide to screen the effective control chemical for brown root rot pathogen. Results show that propiconazole, difenoconazole and difenoconazole+propiconazole show good inhibition effects on the pathogen. This study used fungicide(50% propiconazole+difenoconazole EC 100X) to inject into Ficus microcarpa and Ficus benjamina and determine the distribution of both fungicide inside the tree body. Results show that propiconazole and difenoconazole is existing in the 30 cm point below the injected site on 5th,10th and 15th day. In the last of this study, we test the survival rate of pathogen under different pollution treatments within 10 days. Results show that treatments of urea, Bidens pilosa var. radiate and cabbage can reduce the survival rate of pathogen, especially urea, which can lead to the 0% of survival rate of pathogen after 8th day.To avoid using large amount of fungicide, we expect to reduce the impact of fungicide on the environment by using biological control and trunk injection methods in controlling this disease.
Subjects
Actinomycetes
brown root rot disease
Phellinus noxius
biological control
trunk injection.
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-105-R02633010-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):0bf9a9e2524cfdfe9c26837d0a0552ff