The seed‐borne fungi of Chinese cabbage (Brassica pekinensis), their pathogenicity and control

Abstract

The pathogenicity and control of seed‐borne fungi of Chinese cabbage (Brassica pekinensis) were studied to evaluate the quality of imported seed lots on the Finnish market and to develop practical methods for seed health testing. Amongst the numerous fungal species in the seed lots, nine were found to be pathogenic on B. pekinensis seedlings, Alternaria raphani and A. brassicicola being the most common and the most pathogenic. A. brassicicola was effectively controlled by dressing seed with thiram or powdered Streptomyces griseoviridis. unlike A. raphani which was mostly located in the inner parts of the seed. Water agar was successfully used as an incubation medium for seed health testing. Surface sterilization of the seeds with sodium hypochlorite was used to determine the internal infection of A. raphani. A linear relationship between the incidence of A. brassicicola and A. raphani was demonstrated. Ten per cent of the seed lots were excluded from seedling production because of high infection with A. raphani.

Evaluation of non-chemical seed treatment methods for control of Alternaria brassicicola on cabbage seeds

“…The activity of Mycostop Mix against A. brassicicola observed in the present study confirms previous reports (Tahvonen & Avikainen 1987, Valkonen & Koponen 1990, White et al 1990) of control of A. brassicicola on cauliflower, cabbage and Chinese cabbage (Brassica pekinensis) by S. griseoviridis strain K61, the active microbial ingredient of Mycostop.…”

Frequency of Alternaria brassicicola in commercial cabbage seeds in Japan

“…The predominance of A. brassicicola on cabbage seeds is confirmed from trials with more than ten lots elsewhere, even in lots with frequent infestation with A. brassicae (Holtzhausen and Knox-Davies 1974;Humpherson-Jones 1985;Maude and Humpherson-Jones 1980b;Petrie 1974;Pound et al 1951;Richardson 1970;Tahvonen 1979;Tohyama and Tsuda 1985;Wu and Lu 1984). However, seeds of other hosts of A. brassicicola in Japan tended to be infested with Alternaria pathogens other than A. brassicicola (Tohyama and Tsuda 1995;Valkonen and Koponen 1990). For seed production, cabbage needs vernalization at a colder temperature than other crucifer crops, as hypothesized by Tahvonen (1979).…”

Screening of fungal antagonists against yellows of cabbage caused by Fusarium oxysporum f. sp. conglutinans

“…Species of Aspergillus, Cladosporium, Gliocladium, and Penicillium were common, and species of Penicillium were the most prevalent among seedborne fungal isolates (36%). There are some reports on a trial for investigating the incidence of seedborne fungi (El-Nagerabi and Elshafie 2001;Sinclair 1991;Valkonen and Koponen 1990). El-Nagerabi and Elshafie (2001) investigated the incidence of seedborne fungi in Sudanese lentil seeds: Aspergillus was the most prevalent genus, followed by the Rhizopus, Penicillium, Fusarium, Chaetomium, and Cladosporium.…”