In a one year experiment under orchard conditions in an organic Conference orchard, a single treatment with 500 l/ha beetroot Vinasse was tested as a means to reduce the formation of ascospores in the over wintering leaves. Vinasse was applied with an orchard sprayer at the beginning of the leaf-fall period, diluted 1;1 with water. Directly after the completion of the leaf-fall large amounts of leaves were gathered in the orchard to be over wintered in wire mesh cages on the open ground. The fine wire mesh did not allow large earthworms to come in and take away the leaves. When ascospores were ripe in spring, samples were taken from these cages for the detection of ascospores. This was done using a water bath method after an incubation period in the laboratory. Vinasse applied in this way did not lead as expected to a reduction of the potential ascospore discharge but, on the contrary to an increase in ascospore discharge of 45%. This result differs from results in earlier trials. A satisfying explanation could not be found thus far. For the time being the leaf fall treatment with Vinasse against scab should be advised against
