Phosphonat zur Bekämpfung der Phytophthora infestans bei Kartoffeln – eine mögliche Alternative zu Kupfer?

Summary in the original language of the document

Since more than hundred years, copper-products are used to control late blight of potato, caused by Phytophthora infestans. However, the heavy metal copper accumulates in the soil and affects soil flora and fauna. For this reason, copper agents are listed in the EU only until the end of November 2016. In conventional and integrated farming, copper products have been replaced by synthetic fungicides. In organic production, intensive research is conducted to develop effective alternatives that could replace copper fungicides.
In Germany, plant strengthening agents based on phosphonate are allowed to be used in organic viticulture until the end of the flowering period to control downy mildew. However, if vine plants are treated with phosphonate after flowering, residues remain in the grapes. Nevertheless, the use of these products in viticulture enabled a reduction in copper treatments.
Potato field trials were conducted in order to investigate whether phosphonate products can entirely or partially replace copper fungicides. Another aim was to clarify to what extent residues can be reduced with applications limited to a particular time or growth stage period.