Trnka M. author Hlavinka P. author Semerádová D. author Dubrovský M. author Žalud Z. author Možný M. author text journal article 2007 The relationship between detrended district yields of spring barley (1961-2000) and meteorological drought was assessed by Palmer Z-index. We found that the seasonal water balance (April-June) significantly (P = 0.05) influences the spring barley production in 51 out of 62 evaluated districts. Coefficients of correlation varied in individual districts from 0.19 to 0.70, with the highest values being found in southern Moravia. Data analysis revealed the presence of six distinct groups of districts with a specific drought-yield relationship. The most drought-sensitive cluster included five districts in the South East of the country. On the other hand, the districts in Northern Moravia and Silesia belong among the least sensitive to agricultural drought. The study also defined threshold values of seasonal drought (sums of relative Palmer Z-index lower than -8 and -10, respectively), below which medium to severe spring barley yield reductions are very likely, regardless of the district of occurrence. Hordeum vulgare L.; Palmer Z-index; climatic conditions; yield; drought 10.17221/2210-PSE https://pse.agriculturejournals.cz/artkey/pse-200707-0004.php https://pse.agriculturejournals.cz/artkey/pse-200707-0004.php continuing 53 7 306 316 2007 12141178 periodical academic journal