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Vegetable-prawn culture system. Rice-prawn culture system.
Integrated Rice-Prawn Culture
Rice-fish integrated culture is an age-
old practice in the country, but rice-
prawn culture perse was not introduced
until early 1980. In common with the
rice-fish culture system, the rice-prawn
farms have peripheral trenches of 2-3
m wide and 1 m deep. In larger fields,
diagonal or transverse ditches arc also
dug to connect the peripheral trenches.
A typical annual cycle of rice-prawn
production is illustrated in Fig. 3. Juvenile
prawns of 2-5 g, caught from natural
waters, are stocked at 1-2 animals∕m*
during the first rice crop in the early
part of the year, when juveniles arc
more abundant. Whereas most prawns
are normally raised for eight months to
reach market size, some are harvested
earlier. The major growth takes place
during the rainy season from May to
October. In addition to natural food,
prawns are fed with rice bran mash. The
prawn production ranges from 200 to
Fig. 3. Annual cycle for rice-prawn
production.
400 kg∕ha∕ycar with a gross income of
USS600-1,200, which far exceeds the
income from the rice crops generated
from a shared riceficld.
Both integrated rice-prawn and
vegetable-prawn farming have large
potential for development in the Mekong
Delta, because of the existence of vast
irrigated areas suitable for prawn culture.
The reported rapid increase in the
popularity of rice-prawn fanning in certain
areas of the delta suggests that farmers
have accepted the concept and arc
confident of the economic viability of
the system.
One major concern to rice-prawn
farmers has been the use of pesticides
such as Endrin, Parathion and Monitor.
Freshwaterprawn farming is a relatively
new activity in Vietnam and research
on pond management is needed to improve
the production and income of the farmers.
sβ>
C.K. Lw is from the Asian Institute of
Technology, P.O. Box 2754, Bangkok, Thai-
land, and C. LEE is from the Queensland
Department of Primary Industries, Brisbane,
Queensland, Australia.
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NAQA1 THE ICLARM QUARTERLY