Abstract. The aim of this experiment was to measure the impact of weather conditions on the yield of lemon balm and peppermint drug and content of rosmarinic and caffeic acid. Lemon balm and peppermint are medicinal plants from Lamiaceae family. To assess the quantitative-qualitative indicators were sampled plant material from production stands lemon balm and peppermint. Samples were collected from two cultivation plots at the site Plavnica for five years from 2004 to 2008. The production areas were located in the village Plavnica, the land units that operated company Agrokarpaty, s.r.o Plavnica. The average yield of dry drug to all variants was 1 131,55 kg ha-1. Rosemary acid content in the dry tops balm was 28 613,8 mg.kg-1 (2007) to 36 532.4 mg.kg-1 (2006)The average yield of peppermint dry drug at all variant 1 621,9 kg.ha-1. Rosemary acid content in the dry peppermint was recorded from 3 725.98 mg.kg-1 (2006 plot Pani Hura) to 5 223.0 mg.kg-1 (2008 plot Dziloh). Based on the results we can conclude that with increasing harvest increased the content of rosmarinic acid and caffeic acid too

Key words: lemon balm, peppermint, rosmarinic acid, caffeic acid

Presentation: oral