Book of Abstracts
11th IFOAM Scientific Conference
11-15 August 1996, Copenhagen, Denmark
Swedish University of Agricultural Sciences Unit for Applied Plant Protection, P.O. Box 7044S-750 07 Uppsala, Sweden
The aim for the ecological farmer must be to produce food of good quality without too big fluctuations in quantity. This must be done without the use of pesticides. Since 1988 field surveys have been carried out in the area around Uppsala, concerning the occurrence of pests and diseases in commercial ecological farms. Totally 242 crops have been surveyed.
The aim of these studies has been to find out what pests and diseases that are of importance and how serious they are. Another aim has been to try to explain the variation of outbreaks in time and space. This material and other studies and observations contribute to the understanding and knowledge of pests and diseases in ecological farming.
Attacks of Rhopalosiphum padi in oats have been smaller in the ecological fields compared to conventional fields in the same region. This can not be shown in barley. In individual ecological fields though the attacks can get quite serious. We have not seen that the attacks of Sitodiplosis mosellana and Contariniatritici are greater in either of these farming systems. However, in both 1991 and 1994 the heaviest attacks have been found in ecological fields. Oscinella frit can cause great problems in years with favourable conditions.
The problems with Pseudocercosporella herpotrichoides is generally much smaller in ecologically farmed fields than in conventionally farmed. In peas it is Cydia nigricana that has drawn our attention. We have seen that the attacks vary a lot between different farms, the variation between years is smaller. In potatoes Phytophthora infestans is the most important disease.
To raise the level of cropping reliability in ecological farming the farmers must be aware of what the problems might be and have biological knowledge about the different pests and diseases. In relation to this she/he can then adopt a suitable (varied) crop rotation, take use of cultivation techniques, cultivate resistant varieties (variety mixtures), use healthy seed and make use of forecasts for different pests and diseases.