http://orgprints.org/9449/ Field efficacy of new compounds to replace copper for scab control in organic apple production Efficacy of compounds was investigated in field experiments in Denmark and the Netherlands according to EPPO guidelines. Some Yucca extracts and potassium bicarbonate had an efficacy similar to sulphur on leaves. Addition of sulphur to Yucca 1 and to potassium bicarbonate increased the level of efficacy to that of copper. This confirms results from earlier years. Although a dose increase resulted in better efficacy, this was more prominent for Yucca1 than for potassium bicarbonate. Heijne, B. de Jong, P.F. Lindhard Pedersen, H. Paaske, K. Bengtsson, M. Hockenhull, J. 8planthealth nl-wur-applied-plant-research int-conf-2007qlif-3-crops eu-repco Field efficacy of new compounds to replace copper for scab control in organic apple production 2007-03-12 Heijne, B.; de Jong, P.F.; Lindhard Pedersen, H.; Paaske, K.; Bengtsson, M. and Hockenhull, J. (2007) Field efficacy of new compounds to replace copper for scab control in organic apple production. 3rd QLIF Congress: Improving Sustainability in Organic and Low Input Food Production Systems, University of Hohenheim, Germany, March 20-23, 2007. application/pdf