Impact Assessment of Phase Manuring on the Water Quality Parameters and Growth Potential of Labeo rohita Hamilton 1822

Abstract

The study was conducted for a period of 90 days, to investigate the Impact assessment of phase manuring on the water quality parameters and growth potential of Labeo rohita (Hamilton 1822) . A total of 120 fishes were stocked having mean length 2.8cm and mean weight 2.50 gm were stocked randomly into 12 experimental and distributed as 10 fish in each FRP tanks. Whole experiment was of 4 different treatments T1(Cowdung 1.5 kg/month at 15 ton / ha / year), T2 (Cowdung 375 / g / week at 15 ton / ha / year), T3 (Vermicompost 1.5 kg/month at 10 ton/ha/year) and T4 (Vermicompost 375 g/week at 10 ton/ha/year), and having three replication of each treatment. During the experiment, values of water quality parameter such as Temperature, pH, dissolved oxygen, CO2, alkalinity and hardness were found within optimal range which was 30.46±0.18 to 27.58±0.40, 8.61±0.19 to 8.17±0.14, 6.00±0.11 to 5.13±0.24, 2.83±0.16 to 2.00±0.01, 165.26±3.54 to 153.60±1.97 and 161.73±2.19 to 154.50±2.22. Fish growth parameters like Specific Growth Rate and Percent Weight Gain was found maximum in T4 (Vermicompost 375 g/week at 10 ton/ha/year) which was 1.44±0.03 and 470.49±11.46 respectively. During the study of plankton, the population of Cyclops were found maximum in T4. The current study suggests that the vermicompost has contributed to an increase in Cyclops population by dominating all zooplankton populations in T4. From the obtained result it can be concluded that phase manuring with Vermicompost 375 g/week at 10 ton/ha/year can be safely incorporated to improve SGR and overall growth performances of Labeo rohita and to enhance primary productivity by increase in Zooplankton populations. newline