Nattapong Supmaneenan. A study on the consumptive use of water hyacinth, water lettuce and duckweed . Master's Degree(Technology of Environmental Management). Mahidol University. : Mahidol University, 2003.
A study on the consumptive use of water hyacinth, water lettuce and duckweed
Abstract:
The main objectives of this research are to study on the Consumptive Use and
growth rate of Water Hyacinth, Water Lettuce, and Duckweed. Consumptive Use is
directly measured with rice lysimeter. The results are compared with Consumptive
Use based on climatological data i.e. Thornthwaite method, Blaney–Criddle method,
Makkink method, Jensen–Haise method, Penman method, and Consumptive Use from
Evaporation pan. This research was conducted at Research and Laboratory Station,
Greater Maeklong Irrigation Project, Amphur Kampangsan, Changwat Nakornpathom
for 150 days (June 14, 2002 - November 10, 2002).
It was found that, the Consumptive Use of Water Hyacinth was significantly
different (p<0.01) from that of Water Lettuce and Duckweed. The average
Consumptive Use of Water Hyacinth, Water Lettuce, and Duckweed was 6.01, 4.86,
and 4.33 mm/day, respectively.
The average growth rate of Water Hyacinth, Water Lettuce, and Duckweed was
6.65, 33.36, and 1,072.07 plants/m2/week, respectively.
In addition, the comparison of the Consumptive Use directly measured and by
computation using climatological data found that, for Water Hyacinth, the
Consumptive Use with Blaney–Criddle method was closest to that measured from
lysimeter because it also used Kc for computation. As to Water Lettuce, Jensen–Haise
method gave the value closest to that measured from lysimeter because it was
proposed in an area having semi–arid climate similar to the climate of the study area
and for Duckweed, both Blaney–Criddle method and Jensen–Haise method gave the
value closest to that measured from lysimeter