| In future, conventionally produced seed will not be allowed for organic farming. Therefore, effective non-chemical methods are needed to control seed-borne diseases. Five important vegetable crops (carrot, cabbage, celery, parsley, lamb´s lettuce) and their most important seed-borne pathogens (Alternaria spp., Phoma spp., Septoria spp., Peronospora valerianellae, Xanthomonas spp.) have been investigated in laboratory, model and field trials. Hot water treatments were made at temperatures of 40 °C and 50 to 55 °C for 10 to 30 minutes, in some cases to 60 minutes. In most cases, seed health tests were conducted according to ISTA guidelines. In case of seed infestation with Septoria species and P. valerianellae, the number of spores or oospores were counted... |
