الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 191 |  |  |
| | | from | 191 | | |
Abstract
In the context of climate change and population growth, aquaponic system plays an important role for food security and economic development, considered to be an innovative, eco-friendly and sustainable technology. It is one of the modern systems that have been used to make the most of the water saving, in addition to integrating the cultivation of fish and plants together in one production system. The main objective of this study was to evaluate the growth performance of Nile tilapia under the aquaponic system and to investigate the effect of system type (aquaponic and hydroponic systems) and flow rate (0.5, 1.5 and 2.5 L/min) on the growth performance of lettuce plants grown in deep water culture technique and nutrient film technique. The obtained results for Nile tilapia fish indicated that fish weight and length increased during the experimental periods. The average fish weight and total length increased by almost 32.13 g and 3.38 cm, respectively after experimental period of 42 days. The condition factor (K) was increased from 1.74 to 1.95% during the experimental periods. While the specific growth rate (SGR) was decreased from 2.90 to 1.77 %/day. The measurements of condition factor (K) and daily weight gain (DWG) showed suitable environment for fish growth and survival rate was 100 % during the experimental periods. The feed conversion ratio (FCR) was increased from 1.31 to 1.57 during the experimental periods. The water quality parameters in the fish tank which presented were remained within the suitable range for the Nile tilapia (Oreochromis niloticus) growth. The obtained results for lettuce plants indicated that the average water temperature and pH in the plants troughs were significantly higher in the aquaponic system than in the hydroponic system. While the average electrical conductivity and dissolved oxygen were significantly higher in hydroponic system compared to aquaponic system for each culture type. The root length gradually increased with increasing flow rate and growth period. The root growth rate was higher in aquaponic system compared to hydroponic system. The nutrients consumption rate, fresh and dry weight of shoots and roots, nutrients concentration in shoots, water use efficiency and yield of lettuce were increased with increasing the flow rate from 0.5 to 1.5 L/min and decreased with increasing the water flow rate from 1.5 to 2.5 L/min. And the best treatment was obtained at the flow rate 1.5 L/min. The former parameters were higher in hydroponic system compared to aquaponic system except for sodium in nutrients consumption rate and nutrients concentration in shoots. The hydraulic loading rate was increased with increasing the flow rate while the nutrient uptake time decreased with increasing the flow rate. The results also indicated that output power values from the solar panel gradually increased with increasing solar radiation and the maximum value was at 12.00 pm. The efficiency of the solar panel ranged from 13.51 to 14.68% during daylight hours.