Het cyanophore karakter van witte klaver (Trifolium repens L.)

D. de Waal

Research output: Thesisinternal PhD, WU


The positive correlation found in New Zealand between quality of white clover and its hydrocyanic acid content, could not be confirmed for Dutch white clover in the Netherlands. HCN occurred bound to an incompletely identified glucoside. As Weevers and Treub et al. found the glucoside and HCN contents varying in other plants during the day, the author tried to find out whether similar variations occur in the 1ICN content of white clover. The bromometric method of Schulek was modified so that 1ICN was titrable at a definitely alkaline pH (instead of acid or neutral). The experimental plants were grown under close control: constant illumination, and, within limits, usually constant temperature and air humidity.

HCN in Dutch and New Zealand white clover increased rather sharply after sunrise, reaching a maximum rather soon (e.g. after 4 h), then decreasing. This variation only occurred if the weather conditions of the successive days were much alike. Otherwise it was disturbed, often with a second maximum after noon. A maximum must be assumed for the night also. At least 50 leaves must be analysed.

These and other results seemed sufficient to start breeding research on HCN content in the Netherlands.

Original languageDutch
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
  • Mayer Gmelin, H.K.H.A., Promotor, External person
  • Tendeloo, H.J.C., Promotor, External person
Award date6 Jul 1942
Place of PublicationWageningen
Publication statusPublished - 1942
Externally publishedYes


  • trifolium repens
  • botany

Cite this

de Waal, D. (1942). Het cyanophore karakter van witte klaver (Trifolium repens L.). Wageningen: Veenman.