Book of Abstracts
11th IFOAM Scientific Conference
11-15 August 1996, Copenhagen, Denmark
Danish Institute of Plant and Soil Science, Department of Ornamentals, Kirstinebjergvej 10, DK-5792 Aarslev, Denmark
Problems with fungal diseases in organically grown horticultural crops are very common after few seasons, especially when rotation is not used or impossible in greenhouses. To prevent such problems a combination of different methods has to be used. Besides use of growth prevention methods, the most suitable methods at the moment are use of resistance varieties, but this is not enough to solve the problems and alternative methods have to be taken into account for combating the disease problems. In 1993 a research program was started aiming at preventing fungal diseases in cabbage, onions and greenhouse cucumber.
The following items have been carried out: Seed treatment of cabbage with commercial biological control preparates (biopesticides) as prevention against damping-off caused by the fungus Pythium. Screening for resistance against downy mildew in onions - method development. Prevention of black leg (Pythium ultimum) in greenhouse cucumber. The following subjects have been examined: a) Screening of varieties for resistance to Pythium ultimum
b) Induction of systemic resistance
c) Grafting of seedlings on resistant root stocks
d) Biological control using natural antagonistic microorganisms
e) Use of commercial biopesticides
f) Solarization (see poster by Christensen & Tinggaard)
Preliminary results of the investigations will be shown and discussed.
Thinggaard, K. , Larsen, H. & Hockenhull, J. (1988): Antagonistic Pythium againstpathogenic Pythium on cucumber roots. Bulletin OEPP/EPPO Bulletin, 18, 91-94.