Introduction
One of important problems for farmers are weeds, which compete with cultivated
plant for water and nutrients. Many of herbicides are used for controlling weeds, but these
synthetic compounds contaminated in soil and ground water. Plant extracts were applied as a
bioherbicides in order to reduce chemical usage. In Thailand, many of plant species were
investigated for bioactive compounds such as coumarins, phenolic compounds and alkaloids
which could be isolated from plants in the many families e.g. Rubiaceae, Rutaceae,
Meliaceae and Asteraceae etc.
Haldu (Haldina cordifolia (Roxb.) Ridsdale) is the member of Rubiaceae family
which is widely distributed in continental Southeast Asia, including Thailand where it is
known from almost all Floristic Regions. It is medium size to tall tree (12 – 20 m. in height).
The leaves are simple, cordate shape, the margin entire. Interpetiolar stipules are prominent,
adpressed in bud. The inflorescences are white to yellow head. Flower are 5 merous and
hermaphrodite (Puff et al., 2005).
Department of Botany, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
Corresponding author, b5310402969@gmail.com2
This study aimed to investigate the inhibitory effect of lipophilic extracts of Haldu on
seed germination and seedling growth of weeds and cultivated plants. Moreover,
phytochemical screening of the extracts from bark and leaves of this plant had been done in
order to lead to pure bioactive compounds.