Allelopathic potential of Jasonia montana (wild plant) to control weeds of family Convolvulaceae

We studied the allelopathic activity of Jasonia montana (Asteraceae) aerial parts against 4 weeds spp: Convolvulus arvensis, Calystegia inflata, Portulaca oleracea and Arabidopsis thaliana. Both ethyl acetate and butanol extracts had LD₅₀ value 800 µg ml⁻¹ and 810 µg ml⁻¹, respectively for C. arvensis. These extracts had LD₅₀ values of 1000 µg ml⁻¹ and 1180 µg ml⁻¹ when tested on C. inflata, respectively. The active principle was purified by HPLC and the molecules structure was determined by ¹ HNMR, ¹³C NMR, MS and UV spectroscopy. Bioassay guided isolation showed that 8 phytotoxic compounds including six flavonoids caused the reductions in C. arvensis total biomass fresh weight by: (6,3’-dihydroxy-3, 5,7,4’-tetramethoxyflavone (86.48%), dihydro-quercetin (89.77%), 3, 6, 7, 3’,4’-pentamethoxyflavone (89.95%), 6,4’-dihydroxy-3,7-dimethoxyflavone (91.85%), 6, 4-dihydroxy-3, 5, 7-trimethoxyflavone (90%) and quercetagetin 3, 5, 6, 7, 3’, 4’-hexamethyl ether (83.02%), when compared to its control. Also, one sesquiterpene (Eudesm-4(15), 11(13)-diene-12,5β-oIide) and one polyphenols (3, 5-dicaffeoyl quinic acid) decreased C. arvensis total biomass fresh weight by 85.27% and 88.39% over the untreated control. The diverse pre-emergence and post emergence herbicidal activity of J. montana indicate that natural herbicides may be used to manage C. arvensis weeds.