Modified photoperiods and light intensities for grow-out production of nile tilapia (O. niloticus) under indoor tank culture system

The study aimed to evaluate the effect of modified photoperiods and light intensities on grow-out production of tilapia under indoor tank culture system; specifically on water quality and on growth performance of tilapia. The study was conducted inside the greenhouse and considered two factors: photoperiod (24L:0D, 20L:4D and 16L:8D); and light intensity (40 watts m-2, 60 watts m-2 and 80 watts m-2); also, a control treatment was set-up outside the greenhouse to receive the normal environmental condition. Light manipulations inside the greenhouse were able to sustain the water quality within the desirable level for tilapia cultured in tank; while control tanks shows high water quality variation. Growth performance of tilapia cultured in tank responds positively in prolonged photoperiod at different light intensities. However, light manipulation gave insignificant difference on feed conversion ratio and survival rate compared to normal condition. Results indicated that 20-hours photoperiod and 40 watts m-2 light intensity is just enough to sustain the recommended water quality and better growth performance of the cultured tilapia in indoor tank system. It can be concluded that longer photoperiod and restrained light intensity can improved the growth performance of tilapia under indoor tank culture

Rice Straw Geotextile As Ground Cover ForSoil Erosion Mitigation

Generally, the study aimed to mitigate soil erosion using rice straw geotextile as ground cover. Specifically, it attempted to: evaluate the effect of RSM and RSN as ground cover in mitigating soil erosion at varying slope gradients and different rainfall intensities, and; determine the relationship of slope gradient versus sediment concentration, sediment yield and quantity of soil loss at different levels of rainfall intensity. Results revealed that RSGT as ground cover greatly affected soil erosion. Under rainfall intensities of 75, 100 and 125 mm/hr, RSM had significantly lower soil loss as compared to RSN, CCN And NGC. However, RSN and CCN were comparable with each other but differ significantly with NGC.  Sediment concentration, sediment yield and soil erosion exhibited a nonlinear relationship with slope gradient. At any given level of rainfall intensity, the three indicators increased correspondingly as the slope was increased from 10 to 35o and then  declined when  the slope was further  increased from 35 to 60o. Sediment concentration best fitted (R2 = 0.977) in a quadratic model in the form of a second-degree polynomial equation: SC = 0.551 + 0.626S - 0.008S2 Likewise, observed sediment yield best fitted (R2 = 0.954) a second degree polynomial equation as expressed by a quadratic model: SY = 356.0 + 61.70S – 0.972S2 Moreover, the observed soil erosion was best modeled with R2 = 97.1% confidence by a second degree polynomial equation. The regression model is quadratic in form and is given by the equation: SE = 68.92 + 11.11S - 0.174S2. Keywords: rice straw, geotextile, ground cover, soil erosion, mitigation, rainfall simulatio

Indoor production of loose-leaf lettuce (Lactuca sativa L.) using artificial lights and cooling system in tropical lowland

In the Philippines, crop production hindrances are climate change effects, typhoon occurrences, seasonal dependent cropping pattern and decreasing farm areas. There is a need to strategize farming technologies. Controlled environment agriculture (CEA) has potential in addressing these issues. A farming set-up in controlled environment was developed using locally available materials, light emitting diodes (LED) as sole-source of light and cooling system for temperature manipulation. This study was conducted to benchmark temperature and light intensity requirements for growing loose-leaf lettuce in lowland tropics. Light intensities of 50, 100 and 150 μmol m-2 s-1 were tested under temperature settings of 25 °C and 18 °C. Carbon dioxide and relative humidity were maintained at recommended levels. In actual chamber condition, average day/night temperatures inside were 25.3±0.4/25.5±0.2 °C and 18.9±0.6/18.7±0.3 °C, for the first and second cycles, respectively, whereas, day/night temperatures outside chambers were 29.6±2/25.9±0.5 and 26.2±1/23.6±0.6 during the first and second cycles, respectively. Under two temperature settings, best yield per unit area was observed at required light intensity of 150 μmol m-2 s-1. No significant difference in productivity was observed under 25 °C and 18 °C. Also, no significant difference in productivity was observed between plants in two temperature settings and plants outside

Indoor production of loose-leaf lettuce (

In the Philippines, crop production hindrances are climate change effects, typhoon occurrences, seasonal dependent cropping pattern and decreasing farm areas. There is a need to strategize farming technologies. Controlled environment agriculture (CEA) has potential in addressing these issues. A farming set-up in controlled environment was developed using locally available materials, light emitting diodes (LED) as sole-source of light and cooling system for temperature manipulation. This study was conducted to benchmark temperature and light intensity requirements for growing loose-leaf lettuce in lowland tropics. Light intensities of 50, 100 and 150 μmol m-2 s-1 were tested under temperature settings of 25 °C and 18 °C. Carbon dioxide and relative humidity were maintained at recommended levels. In actual chamber condition, average day/night temperatures inside were 25.3±0.4/25.5±0.2 °C and 18.9±0.6/18.7±0.3 °C, for the first and second cycles, respectively, whereas, day/night temperatures outside chambers were 29.6±2/25.9±0.5 and 26.2±1/23.6±0.6 during the first and second cycles, respectively. Under two temperature settings, best yield per unit area was observed at required light intensity of 150 μmol m-2 s-1. No significant difference in productivity was observed under 25 °C and 18 °C. Also, no significant difference in productivity was observed between plants in two temperature settings and plants outside

Modified photoperiods and light intensities for grow-out production of nile tilapia (

The study aimed to evaluate the effect of modified photoperiods and light intensities on grow-out production of tilapia under indoor tank culture system; specifically on water quality and on growth performance of tilapia. The study was conducted inside the greenhouse and considered two factors: photoperiod (24L:0D, 20L:4D and 16L:8D); and light intensity (40 watts m-2, 60 watts m-2 and 80 watts m-2); also, a control treatment was set-up outside the greenhouse to receive the normal environmental condition. Light manipulations inside the greenhouse were able to sustain the water quality within the desirable level for tilapia cultured in tank; while control tanks shows high water quality variation. Growth performance of tilapia cultured in tank responds positively in prolonged photoperiod at different light intensities. However, light manipulation gave insignificant difference on feed conversion ratio and survival rate compared to normal condition. Results indicated that 20-hours photoperiod and 40 watts m-2 light intensity is just enough to sustain the recommended water quality and better growth performance of the cultured tilapia in indoor tank system. It can be concluded that longer photoperiod and restrained light intensity can improved the growth performance of tilapia under indoor tank culture