The extracts from sunflower and mustard leaves were separated using SPE-Columns. The mustard seeds were germinated on water
(24 h) and subsequently on crude extracts or separate fractions. The heat production rate was measured by isothermal calorimetry
at 21°C and changes in seed cotyledons by FT-Raman spectroscopy. Crude extracts strongly inhibited seed germination. The water
and ‘methanol’ fractions of mustard and sunflower extracts have a similar influence on the pattern of heat efflux. FT-Raman
spectroscopy showed that extracts caused changes in cotyledons mainly in the content of fatty acids, carotenoids and flavonoids.
Isothermal calorimetry and Raman spectroscopy are useful for the study of allelopathic interactions.