The Effect of Nitrogen Fertilization on the Herb Yield of Dragonhead

Authors

• B. Galambosi Agricultural Research Centre, South Savo Research Station, Karila, 50600 Mikkeli
• Y. Holm University of Helsinki, Department of Pharmacy, Pharmacognosy Division, Fabianink. 35, SF-00170 Helsinki, Finland

DOI: https://doi.org/10.23986/afsci.72369

Abstract

The influence of a top-dressing of nitrogen fertilizer (calcium nitrate, CaNO3) on the individual plant height and weight, herb yield and nitrate content of dragonhead (Dracocephalum moldavica L.) was studied in 1987 in Puumala, Finland. The nitrogen doses applied ranged from 0 to 270 kg/ha. Nitrogen fertilization increased both the individual plant height and weight, the fresh and dry herb yield and the nitrate content of the plants. However, no optimum nitrogen dose could be found since the maximum was not reached in most of the cases. An exception was the herb yield (d.w.) of transplanted plants, harvested at the flowering stage, where a nitrogen dose of 70—80 kg/ha gave the highest yield. If the plants were allowed to grow a few weeks more the yield was four fold compared to the earlier harvesting. Sown plants gave a yield two times higher than the transplanted plants, but this was partly due to the greater plant density on the sown plots.