Carnation wilt diseases caused by fungi in Finland

From 81 carnation samples collected in 1967—68 from nurseries in different parts of the country were identified 17 species of fungus, from a total of 177 fungus isolates. Among these, Fusarium oxysporum was most widespread, 31.1 %. F. arthrosporioides, F. avenaceum, F. culmorum, Alternaria tenuis and Cladosporium sp. occurred in considerable quantities. The percentage of Phialophora cinerescens was 1.1 %. In the inoculation trials F. oxysporum behaved as a strongly pathogenic, infecting plants via the air through cut surfaces and via the soil by root-penetration. A. tenuis, F. avenaceum and F. culmorum infected carnations only from the air through cut surfaces. In the fungicide trials against F. oxysporum, spraying the plants infected via the soil proved ineffective. The trials were made with the systemic Benlate (1-(butylcarbamoyl)-2-benzimidazole carbamic acid, methyl ester 50 %), Plantvax (2,3-Dihydro-5-carboxanilido- 6-methyl-1,4-oxathiin-4,4-dioxide), Vitavax (2,3-Dihydro-5-caboxanilido-6-methyl-1,4-oxathiin), and with the non-systemic Dithane M-45 (mancozeb 80 %), Orthocide 50 (captan 50 %) and Pomarsol Forte (thiram 80 %). The dipping of rooted cuttings into Benlate and Dithane M-45 compounds to a certain extent delayed the process of wilting.