Photosynthesis and transpiration rates in the interval of 30 min before and 30 min after copper fungicide application show an increase from the level of 5.0 to 7.0 µmol CO 2 /m 2 /s and 0.75 to 1.00 mmol H 2 0/m 2 /s. Long-term measurements show that the increase of photosynthesis rate after copper application is temporal and fades away after 10

ABSTRACTagnus is a Czech hybrid hop cultivar and a statistically significant influence of depth and term of pruning on harvested hop cones yield and on alpha-bitter acids content in hop cones were found in this study. Evaluated agrotechnical measures, i.e. depth of pruning, term of pruning and number of trained bines, considerably influenced performance and quality of newly grown hop genotype. Every year, we found a positive influence of shallow pruning on yield (increase of dry hop cones yield in 2003 by 0.37 t/ha, in 2004 by 0.28 t/ha and in 2005 by 0.02 t/ha). The hop yield of plants treated with shallow pruning increased on average by 11.6% in three years. We proved a statistically significant influence of three-bines training system on one hop pole, i.e. 3 + 3 bines from each plant. We found that alpha-bitter acids content corresponds with cones yield and indicates a convenience of shallow pruning. Pruning term influenced alpha-bitter acids yield and dynamics of their formation (in the first pruning term yield it was 155 kg/ha, in the second pruning term it was 169 kg/ha, and in the third pruning term it was 175 kg/ha).

In the Czech Republic breeding of new hop varieties is traditionally performed. Its properties correspond with the requirements and interests of end users, in particular hop growers, brewers and especially beer consumers, who with an increasing favor taste new types of beer. The study presents 8 new promising aromatic genotypes, whose major part (Uran, Juno, Ceres, Jupiter, Eris and Most) is already in the registration process of ÚKZÚZ of the Czech Republic (Central Institute for Supervising and Testing in Agriculture CISTA). The tested genotypes were described using brewing tests. Regarding the character of the tested hop varieties, there was chosen a uniform and simple infusion recipe with a top fermentation and dry hopping. The final beer samples were evaluated using chemical and sensorial analyses focusing on a hop aroma. All beer samples were rated as very good, the overall impression of the samples on the scale of 1 to 9 ranged from 2.9 to 3.1. The hop aroma and also bitterness character of the final beer samples were evaluated of high quality. Depending on the hop profile of the beer samples, there were suggested beer styles where the given varieties can be successfully used. These results indicate a high potential of these varieties for the use in brewing practice. Finally, the probability of perceiving a particular hop aroma in beer given by perceiving the aroma in hops was determined by Bayes’ theorem. It was found that probability particularly for spicy, resinous, herbal, citrusy, floral, fruity and grassy aroma was 100, 100, 100, 40, 38, 43, and 100%, respectively.

No abstract