Paper Title
Study on Yield and Grain Quality Stability of Wheat Grown as Varietal Mixtures in Organic Farming

Abstract
In the two year experiment there were seeded four varieties of winter form of common wheat (Triticumaestivum L.), namelly: Butterfly, Illusion, Lorien, Vanessa in three different experimental way. The first design contained the single seeded varieties (only Butterfly, Illusion, Lorien, Vanessa); the second design contained the mixture of two varieties that were sown in a clasiclines width of 12,5 cm (Butterfly + Lorien, Butterfly + Vanessa, Illusion + Lorien, Illussion + Vanessa); the third design contained also of the same mixture of varieties, but they were seeded row by row as single in a line. All the experimental versions were seeded in three replications. The experiment was made under organic farming conditions at the experimental feld of the faculty at the Zvíkov (Czech Republic). During the experiment wereevaluated basic parameters as length of stalk, numbers of spikes before harvest, grain yield, volumeweight and protein content. The data were processed by the programme Statistica 12. The length of the stalk was mainly influenced by variety, orthe influence of the combination of variety was recorded. The method of wheat seeding (mixture / row by row) had a minimal effect. Based on the calculation, the number of spikes before harvest was again influenced by the factor of variety. Compared to the both growing years, the influence ofthestandorganizationwas not confirmed, resp. singlesowing vs. row by row. The grain yield was influenced more by the variety or their combination. The effect of row (seed variety mixture / row by row) wasmarginal. Theeffectofthisfactor on yieldwasthussimilarin bothyears. According to a numberofauthors, the wheat has an autoregulatory capacity and it is clear from the analyzed data that the method of plant seeding (seed mixture or row by row) has virtually no effect on yield. In line with the assumption, the dominant influence of the year effecton all monitored parameters was confirmed. Only the number of spikes before harvest was, in addition to the year, also significantly affected by the way the stand was established (singleseed vs. row by row) from about 13% with the still dominant influence of the year factor (81%). In evaluated data protein content as basic parameter of baking quality of wheat was higher in case row by row seeding. The highest baking quality reached in the single seeded variety Butterfly and its mixtures. The results of our experiment showed that different ways of sowing wheat in organic farming can contribute to the stabilization of yield and grain quality in the even to fan unfavorable year. Keywords – Wheat Varieties Mixtures, Yield, Quality, Organic Farming.