Abstract
The thebaine-yield components in the roots of Papaver bracteatum were studied at various stages of plant development. The maximum concentration of
thebaine was obtained at the start of flowering. However the dry weight of the roots
and the thebaine yield increased until full flowering. Significant differences in
the thebaine and dry matter distribution between various parts of the roots were found;
the lower part had a higher concentration of the alkaloid than the upper ones. The
high thebaine yield (2.5 g/m2) obtained during the first growing season is most promising for the exploitation
of the roots as raw material for thebaine production.