QUALITATIVE INDICATORS OF VIRUS-FREE HOPS OF CZECH PROVENANCE

Virus-free hops give higher yield and have considerably higher content of a-bitter acids. This increase is 50 to 100% according to year-to-y ear variations. On the other hand, beta-bitter acid content is only sl ightly higher (10%), alpha/beta ratio changes from 0.8-1.0 values for control hops to 1.3-1.4 values for meristems. Hop bitter acids and hop oil analyses proved that virus-free hops hold most of typical genetic features of saaz semi-early red-bine hop. Further extension of virus- free hop garden area seems to be long-term stability factor of Czech h op industry.