Doc. Osvald's legacy to current hop testing
Ing. Jarostlav Linhart, Director of Hops Division, ÚKZÚZ atec Branch
Doc. Karel Osvald began breeding hops in 1927, originally he observed 276 clones, 17 of these he kept for further observations, and out of those 3 were given for propagation. The 3 Osvald clones - 31, 72 and 114 are grown in Czech hop-yards still today, in addition they became the foundation for breeding of our own and foreign fine aroma varieties. Osvalďs clone 72 is still used as a standard for testing of fine aroma varieties. In the practical growing the virus-free clone 72 is expanding the most.
Doc. Osvald wrote a number of expert articles of various topics on hops. In "Český chmelař" we can find his articles on topics: Protection and nutrition of hops, Quality of hops, Polish hop-growing etc. His domain was however breeding and hop genetics. This topic can be found in many articles and his book "Study from hop genetics". The book is 50 years old yet it is still modern.
I perceive as contemporary especially the system of evaluation of new hop varieties, introduced by Mr. Osvald which is used with slight modifications till today. It is comprised of an evaluation of equality, a further commercial evaluation, a mechanical and a chemical analysis.
With the question of yields the author emphasises great fluctuation due to the inequality of cultures of various years. It is therefore necessary to obtain results of more locations and years. Commercial evaluation rates especially the colour of cone and its aroma. This characteristic is considered to be the most important in evaluation of hops during selection process. Osvald found differences in aroma even among 1ndividual clones and he indicated that the aroma of clone 114 was the best. Mechanical analysis of cones determines their construction, the fineness of the spindle, the regularity of folds and the refinement of cones.
At the time chemical analysis was used to determine the content of soft and hard resins, humolon and lupulon. The author warns in this context that with a longer storing time comes a significant decrease of these substances. Furthermore he claims that bitterness and quality of hops are two different aspects and states "Adding bitterness to beer could certainly be achieved by various methods, but providing beer with a lasting aroma, bouquet, simply fine aromatic beer taste can be achieved only through the use of quality hops".
Author warns also against the over-estimation of chemical analysis, which are only a complement of the overall evaluation. He also engaged in criticism of foreign brewers, that our Czech hops had a low content of bitter substances, and as a possible cause he points at a variety and a low precipitation.
The contemporary character of the paragraphs above can be perceived through different aspects. During tests of varieties our institute uses methods, which include modified criteria of doc. Osvald in the area of mechanical and chemical analysis and in the commercial evaluation. Hops is therefore tested in many different aspects all of which have a foundation in works of doc. Osvald.
Already then there were apparent fluctuations in humolon (alpha bitter acids) content in our hops depending on year, yet in general the content was higher, i.e. approx. 5%. A decrease of bitter substances due to a longer storage time was already claimed at that time.
There was also a fluctuation in yields and not only throughout various years. Doc. Osvald noticed some significant differences in clone development based on the same plant. This fact lead him to a conclusion that we cannot exclude possibility of the influence of a certain virus. His idea was confirmed only through a modern technology of treating hops and checks of ELISA test.
Doc. Osvald also studied the ripeness of our clones as an important factor for growers. He discovered that the ripeness fluctuates not only in clones but also in years, soil quality, production place and time of cutting.
| On the average clone | 114 is early,
31 - early to semi-early and
72 -semi-early.
|
His tests with hop hybrids are also very interesting, material was for this purpose was provided by dr. Blattný in 1930 - it was approx. 300 seedlings. Osvald observed their yields, disease resistance - and many seedlings excelled in these qualities. He also observed the quality and the aroma and concluded that it is indispensable to have long-term results to show the effectiveness of suitable growing conditions we have in the Czech Republic.
He also engaged in analysis of varietal problems. It is a pity that his legacy could not be fully realised in this particular sphere.
Applications for the tests and the actual tests of Osvald clones:
As mentioned above, doc. Osvald began breeding hops in 1927 and continued until 1940's, when he worked primarily with three generally known clones no. 31,72 and 114. These were entered as new breeds into tests for registration on 17 February 1945. We can find basic characteristics and the breeding process in their applications.
Further application for these clones was submitted to a value test for the variety register during the existence of ČSR, on 13th March 1947. It was mentioned in the application that the new breeds were entered into independence tests and the test of equality in 1945. However such administration problems connected to the end of WW II did not prevent spreading of new clones.
Final decision in the legal position of these new clones was made in 1952. Central inspection and testing institute for agriculture in Prague, department in atec prepared a proposal for entering of the new clones into the register of permitted varieties. The preamble states according to Act no. 188/1950 Sb that it is possible to put the seeds and plants of permitted varieties into circulation.
Enclosed long-term comparisons and results of practical use do prove better characteristics of Osvald clones compared to the clones of general population.
The proposal is substantiated by mentioning the issue of varieties, as well as long-term yield results and further agriculture characteristics, including equality. According to the list of registration of new breeds Osvald clones no. 31, 72 and 114 were entered in 1945 and registered in 1952. They spread rapidly afterwards and today they create a backbone of the assortment of our varieties because they are grown on the majority of the acreage. Even this year it covers an area of 4982 ha, i.e. 82% of overall acreage (including virus-free plants) according to our register.
Our testing of varieties, represented by ÚKZÚZ in Brno, department atec is still working with the Osvald clones.
A long-term test of these clones was concluded in Hřivice in 1997, now they are still tested in Přílepy. The clone 72 serves as a standard for testing varieties of fine aroma hops. Aside from that characteristics including re-infection are evaluated in virus-free clone 72 at six locations in all hop regions. Results of these tests are published annually in "Chmelařství', at hop conventions and some other occasions. Here is a summary:
Osvald clones no. 31, 72 and 114 correspond trough their characteristics to Saaz semi-early red-bine hops. We can claim through the ratings of characteristics including yield that these clones keep the pace with other clones of Saaz hops in yields, in mechanical and commercial evaluation. With regards to alpha bitter acids there are however some new clones (Podleák) which are better than Osvald clones. Though it is necessary to mention that the content of alpha bitter acids in standard not treated varieties is currently lower than in 1930's.
Osvald clones were also chosen for a virus-free propagation, which brings important economical effect. Virus-free plants of clone 72 have continually higher content of alpha bitter acids by one third compared to a standard not treated clone according to our comparison tests. During the first years of growing the virus-free plants give even 70% higher yield in comparison with the not treated ones. As the time passes there is a decrease of yield which is however still higher than the one of not-treated plants. Re-infection has not been found yet.
As a final tribute to doc. Osvald I would like to partly borrow words of an antique proverb. In my opinion, doc. Osvald reached the Olymp of breeders of fine aroma hops.
