4. Discussion
4.1. Ratoon
Extension work on rice – fish culture in the Mekong Delta, Vietnam, stresses the
importance of the rice ratoon crop as a food source for B. gonionotus. This recommendation
is mainly based on the observation that the main daily gains of B. gonionotus are
noticeably higher in the ratoon crop than in the main rice crop.
The main rice crop is not the most favorable environment to raise fish. With increasing
rice biomass, the primary production by phytoplankton drops severely, resulting in low