Impact of sunflower and mustard leave extracts on the growth and dark respiration of mustard seedlings

The subject of the study was investigation of impact of extracts from sunflower and mustard leaves on growth of mustard seedlings. Seeds of mustard were germinated on water and then grew on aqueous extracts from sunflower or mustard leaves. The specific thermal power during seedlings growth was measured by isothermal calorimetry. Changes in the chemical composition stimulated by extracts were measured by FT-Raman spectroscopy and analyzed with the support of the cluster analysis. The heat production rate during growth of seedlings was related to the type of extracts. Crude sunflower and mustard extracts strongly inhibited the growth of seedlings when compared to non-treated control. FT-Raman spectroscopy confirms that allelopathic compounds have the greatest influence on the metabolism of fatty acids of mustard cotyledons. The obtained results indicate that sunflower and mustard extracts have varied impact on growth and heat production rate of mustard seedlings.