**5. Plant protection products (PPPs) authorized in organic farming**

The crop protection in organic farming is holistic, and, hence, it is extremely difficult to separate inputs as plant nutrients (fertilizers) and plant protectants (pesticides) [6]. Plant protection products authorized for use in organic farming differ among countries depending on the differences in crops, pests, and cropping systems, as well as regulations and standards adopted by these countries [21]. Organically approved pesticides fall into the following groups: biorational, inorganics, botanicals, microbial, oils, and soaps. The most widely used as insecticides are microorganisms, natural pyrethrins, rapeseed oil, and paraffin; the most widely used as fungicides are copper compounds, sulfur, and microorganisms. The rules of organic agriculture allow the use of unregistered products such as nettle slurry, which is used against aphids. It can be prepared on the farm or shared among farmers [21, 22].

The basic substance concept was introduced by the EU regulation 1107 in 2009. It was defined as substance not intendedly used for plant protection purposes; however, it can still be used in protection of plants either directly or as a diluent. According to this definition, substances used as foodstuff such as vinegar and sunflower oil can be used as plant protection [23]. The basic substances of plant and animal origin, which are used as foodstuff, can be legally used in crop protection in organic farming with the exception of being used as herbicides. These basic substances include chitosan hydrochloride, fructose, sucrose, *Salix* spp. cortex, and *Equisetum arvense* L. (field horsetail) which are used as elicitors of the plant

self-defense mechanism. Sunflower oil, whey, and lecithins are used as fungicides, while vinegar is used as fungicide and bactericide, and *Urtica* sp. is used as insecticide, fungicide, and acaricide [21]. In organic farming, only active substances listed in the Commission Regulation (EC) No. 889/2008 (**Table 2**) can be used. New update is frequently being made by the EC to add or remove PPPs from the list.

