Abstract

Abstract. Nowdays, wheat is the most important crop for organic farming system. However, the varieties breeded and tested in the conditions of organic farming system are still missing. It gives rise to very low level of yield in the Czech Republic (less than 50% of level of convention one in the same conditions). One of the reasons is that the ideotype of organic breeded variety is different from conventional one. The varieties suitable for organic farming system differ in many respects from those adopted in conventional farming. The first difference is obvious from the conventional tests of use value of the varieties, taking just some direct indicators influencing the main parameter (yield) into account. Generally speaking, the features to be tested can be divided into 4 groups: the morphological, the biological, the economic and quality parameters. The conventional varieties are bred in conditions characterised by an abundance of soluble nutrients, and therefore, their root systems are not adapted to an insufficiency of nutrients or weaker bonding of nutrients. The competitiveness to weeds has also been ignored. Any conventional variety, which has never confronted any strong weeds during the breeding process, cannot be assumed to be competitive enough in the conditions of an organic agroecosystem. Resistance to diseases and pests can be similarly characterised. The variety is protected by pesticides throughout the conventional breeding process. Because of the seasonal fluctuations in weather, we need a plastic and flexible variety. They are also different from the point of view of their qualitative parameters.