The ÖMKi organized Expert Day took place on March 29, 2017 in Mezőberény, in the vicinity of which are found several organic growers. Around 50 participants took part. The event, which was opened by ÖMKi director Dr Dóra Drexler, was attended by representatives of growers, integrators and retailers related to organic farming. Peter Hertelendy, an expert on plant protection, presented his experiences over the last few years protecting plants and the utmost important defining prevention in organic farming.He went into detail about crop rotation, soil tillage, species selection and the role of agro-techniques in plant-health. Cereal production, for example, leaves chaff on the soil surface that affects not only on its own soil table, but also on neighboring soils, which can endanger the coming year’s cereal prospects, which untilled soil and the imperfect stem-crushing only increase. Experts are well aware of the harmful effects pentosan produces, while at the same time diseases caused by pathogens are more and more common, like the symptoms (fading, staining) that appear on leaves in early spring, which is often linked to the state of enzyme shortage caused by the lack of micro-nutrients. A species’s susceptibility to or resilience against diseases requires constant watch because of new pathogen races appearing year after year, as could have been seen in the case of the yellowrust-infection last growing season. When talking about cereal crop rotations, the danger of blight rises, while in corn crop-rotation the danger of fusarium infestations increase, especially in the case of spring wheat. The presenter also called attention to the fact that toxin quantity is rarely connected to the extent of the infection. On the topic of harmful organisms, it has also come up that the soil reclamation plants containing brassica (canola, mustard) have a part in maintaining the psylloidea, which presents potential danger to the neighboring table. Protection against this can be incorporating it in time and nursing the stubble. In the last few years the common vole has been an increasing problem, whereas putting up 2-3 m high T-trees (4-6/ha) can be a way to counteract them.