Recent investigation on coffee tracheomycosis, Gibberella xylarioides (Fusarium xylarioides) in Ethiopia
The incidence of tracheomycosis, caused by Gibberella xylarioides (Fusarium xylarioides), was assessed in different Arabica coffee fields, each consisting of a large number of selections with known history of coffee tree death, in Ethiopia in 1997. The number of healthy and infected trees were counted and recorded. The pathogenic variability in the fungus population was studied by inoculating 4 representative G. xylarioides isolates collected from different localities (Bebeka, Teppi, Jimma and Gera)on seedlings of 9 Arabica coffee cultivars (74165, 7440, 74304, F-17, F-61, SN-5, 35/85, 24/85 and 61/85) with various levels of resistance to tracheomycosis under field conditions. The disease incidence varied among the coffee selections in the field. At Gera in a field consisting of 1981 CBD resistant selections and including both wilt susceptible and resistant controls, significant differences were obtained in the percentage of dead coffee trees. Some selections such as 8211 and 827 showed low incidence of 4.2 and 13.2 percent, respectively, whereas selections 8214 and 823 had the highest infection levels of 83.4 and 88.9 percent, respectively. The released CBD resistant selection 741 had consistent performance in the field with relatively low tree death rate of about 35.2 percent. In the pathogenic variability study, highly significant differences among coffee cultivars, and among the fungus isolates; and also a significant cultivar x isolate interaction, were obtained both in percentage of dead seedlings and in length of incubation periods. Seedlings of cultivars 61/85, 24/85 and F-17 showed significantly higher disease levels with 62.6, 60.5 and 51.4 percent, respectively.
| Main Authors: | , , , |
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| Format: | biblioteca |
| Published: |
Trieste (Italia) ASIC
2001
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| Subjects: | COFFEA ARABICA, VARIEDADES, RESISTENCIA A LA ENFERMEDAD, ENFERMEDADES FUNGOSAS, ENFERMEDADES DE LAS PLANTAS, ORGANISMOS PATOGENOS, GIBBERELLA, ETIOPIA, |
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| Summary: | The incidence of tracheomycosis, caused by Gibberella xylarioides (Fusarium xylarioides), was assessed in different Arabica coffee fields, each consisting of a large number of selections with known history of coffee tree death, in Ethiopia in 1997. The number of healthy and infected trees were counted and recorded. The pathogenic variability in the fungus population was studied by inoculating 4 representative G. xylarioides isolates collected from different localities (Bebeka, Teppi, Jimma and Gera)on seedlings of 9 Arabica coffee cultivars (74165, 7440, 74304, F-17, F-61, SN-5, 35/85, 24/85 and 61/85) with various levels of resistance to tracheomycosis under field conditions. The disease incidence varied among the coffee selections in the field. At Gera in a field consisting of 1981 CBD resistant selections and including both wilt susceptible and resistant controls, significant differences were obtained in the percentage of dead coffee trees. Some selections such as 8211 and 827 showed low incidence of 4.2 and 13.2 percent, respectively, whereas selections 8214 and 823 had the highest infection levels of 83.4 and 88.9 percent, respectively. The released CBD resistant selection 741 had consistent performance in the field with relatively low tree death rate of about 35.2 percent. In the pathogenic variability study, highly significant differences among coffee cultivars, and among the fungus isolates; and also a significant cultivar x isolate interaction, were obtained both in percentage of dead seedlings and in length of incubation periods. Seedlings of cultivars 61/85, 24/85 and F-17 showed significantly higher disease levels with 62.6, 60.5 and 51.4 percent, respectively. |
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