Paper Title
Biological Activities of Ludwigia Hyssopifolia Crude Extract on Seed Germination and Growth Inhibition of Rice and Spinach

Abstract
Biological activities of crude extract of Ludwigia hyssopifolia (G.Don) Exell were evaluated on seed germination and growth inhibition of monocot and dicot using rice (Oryza sativa L.) ‘Leuang Pratew 123’and spinach (Spinacia oleracea L.) as representatives, respectively. Plants were extracted with 70% ethanol, and extracts at seven different concentrations, 50, 25, 12.5, 6.25, 3.13, 1.56 and 0 (control) mg/mL, were tested in vitro for seed germination and seedling growth. For seed germination, it was found that the extract of Ludwigia hyssopifolia at 50 mg/mL was the most potent with maximum germination inhibition (100%) for both rice and spinach. At lower concentrations no inhibitory effects was found in rice, however, in spinach complete inhibition (100%) was achieved with concentrations as low as 12.5 mg/mL. The inhibitory effects of this extract were also observed on shoot and root growth of both rice and spinach seedlings at all concentrations with varying inhibition percentage according to concentration levels. At the highest concentration (50 mg/mL), no root growth occurred in both plants, and the highest inhibition activities were found on rice (94.79%) and spinach (51.83%) shoots. These results suggest that the Ludwigia hyssopifolia ethanol extract which exhibits allelopathic properties to both monocot and dicot may be useful for future applications as a bioherbicide. Key Words - Allelopathy, ethanol extract, Oryza sativa L., Spinacia oleracea L.