Abstract: We tested pot cultured Vaccaria segetalis(Necr.) Gracke to study the effects of soil moisture on biomass and vaccarin (VR) content of V.segetalis in four different kinds of soil moisture. We determined the biomass and VR content of different organs of V.segetalis after 15, 30 and 45 days in different soil water conditions. The biomass and VR content of V.segetalis are affected significantly by the followed soil water conditions of severe soil drought, moderate soil drought, and excessive soil moisture compared with the control group, and VR content in different organs of V.segetalis can be improved significantly in moderate soil drought condition. The best biomass and VR yield of V.segetalis are in soil moisture of 70% 75% of field capacity. Proper soil moisture was proposed to maintain to balance between yield and quality of this medicinal herb in production of V.segetalis.

Key words: soil water content, Vaccaria segetalis(Neck) Garcke, biomass, vaccarin