DETERMINATION OF THE PHYSIOLOGICAL RACES OF FUSARIUM OXYSPORUM F.SP. DIANTHI ON CARNATION IN EIGHT FARMS LOCATED AT THE BOGOTA PLATEAU

The most limiting disease of carnation in Colombia is the vascular wilt caused by Fusarium oxysporum f.sp. dianthi. In order to determine the physiological races of the pathogen present on eight farms, located at the Bogotá Plateau, 100 isolates of the fungus were obtained from diseased carnation plants.
A conidial suspension in a concentration of one million per mililiter was inoculated in each carnation cutting of the differential varieties Bogotá, Niki, Nora Barlo, Raggio di Sole and San Remo, inmediately before planting.
A split plot design was used.
Each isolate of the fungus was inoculated on nine cuttings of each differential variety.
Evaluation of the disease was done every seven days, during 14 weeks after planting. 98 isolates were identified as Race 2 of the pathogen according to the susceptibility reaction on the varieties Nora Barlo, Raggio di Sole and San Remo and the resistant reaction on the varieties Bogotá and Niki.
Two isolates showed low level of pathogenicity, so it was not possible to identify the race to which they belong.
The 98 isolates belonging to Race 2 showed some differences in pathogenicity and in aggressiveness.
Races 1, 4 and 8 of the pathogen were not found in this research.

International Symposium on Cut Flowers in the Tropics

S. Gómez, F. Mocarí, A.J. Barrera, G. Arbeláez

https://doi.org/10.17660/ActaHortic.1999.482.15