ALLELOPATHIC EFFECT OF TAGETES MINUTA L. WATER EXTRACTS ON SEEDS GERMINATION AND SEEDLING ROOT GROWTH OF ACACIA ASAK

Allelopathic effect of water extracts of Tagetes minuta (Asteraceae) on seed germination and seedling growth of Acacia asak (Mimosaceae) was investigated. The root extracts showed no effect on seed germination percentages while leaf extracts has shown the highest germination inhibition effect. The seedling emergence in sand soil was strongly inhibited by leaf extracts; interestingly, this inhibition of emergence was reduced in sand clay soil. Leaf extracts also had shown the strongest radicle growth inhibition resulted in burning of the radicles' tips. It is concluded that allelochemical exerting the inhibition effect is most abundant in leaves and its effect is reduced with clay sand soil.