Formulated and unformulated carbonates to control apple scab (Venturia inaequalis) on organic apple

Summary

In the EC at the moment only copper- and sulphur-based products are allowed to control
a variety of diseases on different crops. However, it is well-known that these products
also have negative side effects on beneficial organisms and the soil. For many years
researchers have been looking for alternatives to reduce their use and /or replace them.
Bicarbonates have been brought forward for many years. They are present in nature and
were used in the past in organic farming. Up to now, in the EC, carbonates have not been
included in the list of active substances, which may be used as plant protection products.
A good chance exists that this will change in the future, which would open the possibility
to apply for the inclusion of potassium hydrogen carbonate in Annex II B of regulation
EEC 2091/92. Field trials carried out in 2006 and 2007 in South Tyrol evidenced an
interesting efficacy of potassium hydrogen carbonate-based products against apple scab
and other diseases, but also phytotoxic side effects emerged.