Abstract. 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.

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The conventional sowing method of onion seeds offers great wastage and laborious. This study aimed to develop a pull-type onion sowing machine for seedbed to optimize the sowing of seeds, reduce labor cost, yields better quality onion seedlings, and increases income of onion farmers. The machine was tested and evaluated, in comparison with manual sowing of onion seeds, in terms of seed delivery rate, effective field capacity, field efficiency, seeding efficiency and drawbar power. The cost of sowing seeds using the machine was also determined. Results indicated that machine’s delivery rate was significantly reduced to 5.33 g/m2 from 11.35 g/m2 This resulted to reduction in the quantity of seeds sown for a one-hectare onion production area by about 4-5 cams (1.6 to 2 kg). Machine’s field capacity (375.45 m2/h) was higher than of manual sowing (25.51 m2/h). Field efficiency at 86.94% is higher than 60% threshold given by PAES [3]. The seeding efficiency of 89.70% was statistically the same with three seeds per 25 mm hill spacing. The drawbar power was found out to be 0.15 5kW. The cost of the machine is $1,666.67 with a break-even quantity of 9,226.9 m2 or 138.11 cans of onion seeds in 0.62 years.