Performance of Oreochromis niloticus reared in concrete ponds under different fertilization systems [electronic resource].

Includes reference.

An experiment was conducted to study the effect of different organic fertilization systems on water quality and growth performance of male Nile tilapia Oreochromis niloticus reared in concrete ponds (12.5m2 ), stocked with fry (0.21 g/fish× 32/ m3) . The concrete ponds bottom was lined with 10 cm clayey loam farm soil (pH7.5) before filling water. Eight concrete ponds were used in experiment and divided to four treatments with two replicates for each treatment. 1st treatment was fertilized with chicken droppings treated with efficient microorganisms (CDEM). The 2nd treatment was fertilized with Rigir (R). The 3rd treatment was fertilized with Rigir treated with efficient microorganisms (REM). The 4th treatment was fertilized with fish Rigir as control (FR). All treatments were applied at a rate of 75g/ m3 (water volume)/ week during the whole period of experiment 105days. The results should that water quality parameters in the suitable range for growth of Nile tilapia fry in all treatments with insignificant differences (P>0.05) among treatments. Also, there were no significant differences (P>0.05) among treatments for all groups of phytoplankton and zooplankton. The highest final body weight, average daily gain (ADG) , specific growth rate (SGR), condition factors and survival rate were recorded in T4 (FR) group followed by T3 (REM) group, T1 (CDEM) group andT2 (R) group. The same trend was observed by net return of fish. Results of this study supported the using of healthy alternative organic fertilizer in male Nile tilapia (O. niloticus L.) fry during a single-stage nursery-rearing system at a rate of 75g (fish Rigir or Rigir treated by EM )/m3( water volume) /week. From the economic point of view, it can be concluded that, in case of adequate operational financial resources the use of (FR) would be economical, but in case of limited operational financial facilities the use of Rigir as a healthy alternative organic fertilizer treated with EM was the most cost – effective.

Summary in Arabic.

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