The effect of preceding crops on damping-off of sugar beet and some ecological properties of the fungus Pythium Pringsh

The short- and long-term effects of preceding crops on damping-off of sugar beet were studied in pot trials in the glasshouse. Of the different types of plants studied, cereals most effectively decreased disease frequency. At the same time cereals on average also decreased the number of Pythium propagules in the soil, this being a short-and long-term effect. Legumes, on the other hand, seemed not to affect or even to increase damping-off as compared to continuously cultivated sugar beet. The influence on preceding crops on different soil types varied greatly. The inoculum density or potential of Pythium generally correlated poorly with damping-off of sugar beet. Nor did disease transformations cause any overall improvement of correlations.