Barley varieties registered in the Czech Republic after the harvest of 2023 Odrůdy ječmene registrované v České republice po sklizni 2023

After the 2023 harvest, four varieties of spring barley were registered in the Czech Republic. The malting quality was determined in three varieties. After four years of testing, LG Tuplak was registered. After three years of testing, the spring barley varieties LG Lokal, Sting


Introduction
The registered varieties passed three to four different years of testing.The year 2020 was above normal in terms of temperature (9.1 °C) and rainfall (766 mm), the year 2021 was normal in terms of temperature (8.0 °C)

Materials and methods
In the present study, the agronomic characteristics of the barley varieties LG Lokal, LG Tuplak, Sting, and Ranee were evaluated (Table 1).For the non-malting variety Ranee, information is given only in Table 3 without further description.

Malt analysis
The malting quality of the varieties LG Lokal and Sting was determined based on a micromalting test and subsequent analysis of the malt and sweet wort of 12 malt samples obtained between 2021 and 2023.The malting quality of LG Tuplak was assessed based on the results obtained in the years 2020-2023, i.e. based on 16 measurements (Table 2).
The grain samples (grain fraction above 2.5 mm) for the micromalting tests were supplied by the Central Institute for Supervising and Testing in Agriculture (hereinafter referred to as CISTA) in Brno.
The malting of the 0.5 kg samples was carried out in a micromalting plant (KVM Czech Republic).The micromalting was carried out according to the MEBAK method (2018).
Steeping took place in the steeping box for 72 hours with alternating wet stages and air rests.The water and air temperature were maintained at 14.0 °C.Duration of wet stages and airrests: on the first day, the wet stage took 5 hours and airrest 19 hours, on the second day, the wet stage took 4 hours and airrest 20 hours.On the third day, the water content of the germinating grains was adjusted to 45% by steeping or spraying.
Germination took place in the germination box.The temperature during germination was maintained at 14.0 °C.The total germination time was 72 hours.
Kilning took place in a singlefloor electrically heated kiln.The freedrying stage lasted 12 hours at 55 °C.During the forced drying stage, the temperature was gradually increased to 75 °C.The curing stage was carried out for 4 hours at 80 °C.
Malt quality was determined according to the methods described in MEBAK (2011MEBAK ( , 2018) ) and EBC Analysis Committee (2010).The methods used are presented in the table (Table 2).

Selection of the test sites
The basic characteristics of the test sites are given in the Barley Year Book 2023 (Psota, 2023).Each year, grain samples of standard varieties were collected from all test sites.The level of pre-harvest sprouting and nitrogen content were determined in the grain samples collected.Sites with pregerminated grains were excluded from further monitoring.Subsequently, four sites were selected with grain nitrogen contents of standard varieties ranging from 10.2 to 11.0%.From these sites, samples were taken for micromalting and subsequent analysis of the malt produced.

Agronomic characteristics
Information on yield, agronomic data, disease resistance, and mechanical properties of the grain of the evaluated barley varieties was obtained from the state variety trials of the Czech Republic from the testing stations of CISTA and cooperating subjects (Table 3).Significant agronomic characteristics of barley varieties LG Lokal, LG Tuplak, Sting, and Ranee were evaluated based on the results obtained from trials conducted in 2020-2023 and 2021-2023.The yield of grain, yield of grain above 2.5 mm were separately determined for the maize, sugarbeet and cereal, and potato testing areas.The trial areas are described in the Barley Year Book 2023 (Psota, 2023).Furthermore, the disease resistance of the evaluated varieties was determined (Table 3).

Results and discussion
The results of malt and sweet wort analysis of the spring barley varieties LG Lokal, LG Tuplak, and Sting are summarized in table (Table 2).Significant agronomic characteristics are given in Table 3.
The varieties LG Lokal and LG Tuplak recommended for the production of beer with the PGI 'České pivo' (Commission Regulation, 2008) had an extract content in malt dry matter of 82.1% and 83.2% respectively and the required lower proteolytic modification, which was associated with a lower soluble nitrogen and free amino nitrogen content.Cell wall degradation, characterized by friability values, exceeded 80%.The βglucan content of the sweet wort exceeded 250 mg/l.
The variety Sting had the same or higher extract content in the malt dry matter and similar levels of proteolytic modification as the standard varieties KWS Amadora and Spitfire.Sting had similar soluble nitrogen and free amino nitrogen (FAN) content as the standard varieties.The level of cytolytic modification was slightly lower in Sting than in the standard varieties.The quality of the sweet wort composition, determined by the final attenuation achieved, was comparable to or slightly lower in Sting than in the standard varieties.The variety gave a clear to opalescent malt.
LG Tuplak has a malting quality.
LG Tuplak met the requirements set out in the application for the PGI 'České pivo' (Commission Regulation, 2008) and was therefore recommended by the Research Institute of Brewing and Malting for the production of beer with the PGI 'České pivo'.
LG Tuplak is a midlate malting variety.Plants medium to high, less resistant to lodging, medium resistant to stem breaking.1000 grain weight medium to high, grain size fraction >2.5 mm high.
Resistant to powdery mildew of barley on the leaf, medium resistant to leaf rust of barley, medium resistant to the barley leaf (brown) spot complex, resistant to scald of barley, and medium resistant to Fusarium head blight (scab) of barley.High yield of grain over 2.5 mm in both variants of growing in the potato area, medium-high to high in the treated variant of growing in the sugarbeetcereal area, mediumhigh in the untreated variant of growing in the sugarbeetcereal area, and in both variants of growing in the maize area.
The utility value is given by the combination of the high yield of grain over 2.5 mm in both variants of growing in the potato area and the malt quality meeting the requirements for the production of beer with the PGI 'České pivo'.

LG Lokal
The variety LG Lokal, bred in the Czech Republic, gave, at the optimal nitrogen content (11.1%) in unmalted grain, malt with an extract content of 82.1% and optimal level of diastatic power (298 WK).Degradation of nitrogen substances was optimal (Kolbach index 42%).Cell wall degradation was slow.Friability was at the level of 82%, with corresponding βglucan content in the sweet wort (259 mg/l) and a higher viscosity level (1.495 mPa•s).The quality of the sweet wort was very low (apparent final attenuation 79.4%).The FAN content was at a medium level (183 mg/l).In most cases, the variety provided clear sweet wort.
LG Lokal has a malting quality.
LG Lokal met the requirements set out in the application for the PGI 'České pivo' (Commission Regulation, 2008) and was therefore recommended by the Research Institute of Brewing and Malting for the production of beer with the PGI 'České pivo'.
Resistant to powdery mildew of barley on the leaf, medium resistant to leaf rust of barley, medium resistant to the barley leaf (brown) spot complex, medium resistant to scald of barley, and medium resistant to Fusarium head blight (scab) of barley.
High yield of grain over 2.5 mm in the untreated variant of growing in the maize area, mediumhigh in the treated variant of growing in the maize area, and in both variants of growing in the sugarbeetcereal and potato areas.
The utility value is given by the combination of the high yield of grain over 2.5 mm in the untreated variant of growing in the maize area and the malt quality meeting the requirements for the production of beer with the PGI 'České pivo'.

Sting
The variety Sting, bred in Germany, gave, at the optimal nitrogen content (10.4%) in unmalted grain, malt with rich extract content (83.7%) and optimal level of diastatic power (313 WK).The intensity of proteolytic modification was at a very high level (Kolbach index 52%).The sweet wort had a higher soluble nitrogen content (874 mg/l) and a high FAN content in the sweet wort (215 mg/l).The high values of FAN and Hartong index (VZ 45 °C) are associated with a higher value of colour of malt (4.1 EBC un.).Cytolytic modification was at the optimal level.The cell wall degradation was 92 %, the −glucan content of the wort (117 mg/l) and the viscosity value of the wort was at a satisfactory level (1.445 mPa•s).The quality of the wort was low (apparent final attenuation of 80.3%).The variety almost always gave a clear wort.
The Sting variety has a very good malting quality.
According to the EU Plant Variety Database (2024), the variety is registered in Poland, Germany, and France (EUPVP -Common Catalogue, 2024).
Sting is a malting midearly to early variety.Plants are medium-high, medium resistant to lodging, and resistant to stem breaking.1000 grain weight is high, grain size fraction >2.5 mm mediumhigh to high.
The variety is medium resistant to powdery mildew of barley on the leaf, medium resistant to leaf rust of barley, medium resistant to the barley leaf (brown) spot complex, resistant to scald of barley, and medium resistant to resistant to Fusarium head blight (scab) of barley.

Poděkování
Podpořeno Ministerstvem zemědělství ČR, institucionální podpora MZERO1923.variants of growing in the maize area and in the untreated variant of growing in the potato area.
The utility value is given by the combination of a very high yield of grain over 2.5 mm in both variants of growing in the sugarbeetcereal area and in the treated variant of growing in the potato area, high yield of grain over 2.5 mm in both variants of growing in the maize area and the untreated variant in the potato area and very good malting quality.

Conclusion
The study describes the malting quality achieved by the LG Tuplak, LG Lokal, and Sting varieties which were registered in the Czech Republic after the 2023 harvest.The varieties evaluated can be divided into two groups.One group consists of the LG Tuplak and LG Lokal varieties recommended for the production of beer with the PGI 'České pivo'.These varieties mainly show a lower level of proteolytic and cytolytic modification and a lower level of apparent final attenuation.The second group consists of the variety Sting, which is characterized mainly by a high level of proteolytic and cytolytic modification.