There are large amounts of wet lowland areas in Southeast Asia.
Many of these areas have been left as wasteland, but some have
been developed for agriculture, such as paddy fields. Recently, the
consumption of vegetables has been increasing in these areas. However,
there is often an acute shortage of vegetable crops due to the
cultured fields becoming waterlogged, particularly during the rainy
or monsoon seasons. Therefore, new techniques for sweet potato
culture need to be developed to sustain the productivity of vegetable
and root crops, and to make additional lowland areas suitable
for crop culture.