Allelopathic potential assessment of different vegetal extracts on lettuce seed germination

The aim of the present work was to evaluate the allelopathic influence of different vegetal extracts on the seed germination of lettuce (Lactuca sativa) as test plant. Eight experimental variants have been studied (including Control). The species used for aqueous extracts were: Amaranthus retroflexus, Aquilegia vulgaris, Atriplex hortensis, Chenopodium ficifolium, Cirsium avense, Echinochloa crus-galli, Elytrigia intermedia, Juglans regia, Lactuca serriola, Leucanthemum vulgare, Parthenocissus inserta, Phragmites australis, Poa pratensis, Polygonum aviculare, Portulaca oleracea, Sambuscus ebulus, Solidago gigantea, Xanthium strumarium, Convolvulus arvensis, Vicia sativa, Pinus sylvestris, Helianthus tuberosus. Aqueous extracts from fresh biomass were examined under laboratory bioassay in Petri dishes. The obtained results suggest that the extract from common vetch, canada thistle, red-root amaranth, common purslane and cockspur display more serious allelopathic effects on the seed germination of lettuce. Thus, the study of vegetal extracts with potentials allelopathic effect can lead to development of some new herbicides with low environmental impact.