Prior to stocking of spawn in the pond apply any of the following method:
• Dipterex + Sumithion
Use Dipterex and Sumithion to kill the undesired insects and predatory zooplankton
Dose: Decimal/30 cm (1 feet) of water
| Dipterex | Sumithion |
| 13–15 g | 6–7 ml. |
Application:
Dipterex: Twenty four hours before stocking the spawn, apply the desired amount of Dipterex after mixing with sufficient amount of water.
Sumithion: About 12-hour before stocking and 12 hours after application of Dipterex apply the desired amount of Sumithion in the pond after mixing with sufficient amount of water.
These two chemicals are selective poison for larger zooplankton and other aquatic insects which are highly predatory in nature. By killing them you can promote the quick growth of smaller zooplankton (rotifer) which are the choiced food for spawn.
• Kerosine/Diesel Application
By applying kerosine or diesel you can kill the backswimmers and other predatory aquatic insects.
Dose: 125ml/decimal
Application:
Apply the desired amount of oil in the pond. Avoid application during windy days.
In case of wind action, net the pond with fine mesh net then apply the oil when the net is closed. It kills the aquatic insects which comes inside the closed net.
Caution:
Oil application kills only the aquatic insects but not the Cladocerans and Copepods (larger and predatory zooplankton).
Dipterex/Sumithion/oil application is not required during fry to fingerling rearing.
