The main objective of the present investigation is to develop and evaluate the performance of a carrot seeder with 12 vertical rollers with cells metering, The performance of the developed seeder was experimentally investigated in the laboratory under seven metering-device speeds ranged between 20 to 140 rpm and three cellsizes of 1, 2 and 3 seed/cell and tested in the field with uncoated and coated seeds under four forward speeds 2, 3, 4 and 5 km/h. The main results of this study can be summarized in the following points: The maximum seeding rates of 2.218 and 7.863 kg/fed were obtained at metering speed of 20 rpm (ground-wheel speed of 10 rpm) and cell size of 3 seed/cell using uncoated and coated seeds, respectively. Meanwhile, the minimum seeding rates of 0.462 and 2.097 kg/fed were obtained at metering speed of 140 rpm (ground-wheel speed of 70 rpm) and cell size of 1 seed/cell for uncoated and coated seeds, respectively. The maximum carrot-plant emergences of 95.11 and 97.15 % were obtained at forward speed of 2 km/h and cell size of 3 seed/cell using uncoated and coated seeds, respectively. Meanwhile, the minimum carrot-plant emergences of 92.01 and 94.22 % were obtained at forward speed of 5 km/h and cell size of 1 seed/cell for uncoated and coated seeds, respectively. The maximum carrot-fruit yields of 13.11 and 18.62 Mg/fed were obtained at forward speed of 2 km/h and cell size of 3 seed/cell for uncoated and coated seeds, respectively.

The aim of the present investigation is to develop a vertical roller with double grooved rows metering device for garlic cloves planting. Laboratory and field experiments were carried out to evaluate the performance of the developed metering device. Laboratory experiments were conducted using a laboratory test rig under different metering device speeds, agitator speeds and cloves size to estimate cloves discharge and cloves damage. Field experiments were conducted under different planter forward speeds to measure plant emergence percent, garlic-cloves spacing, missing-hills, double-cloves percent and total crop yield. The main results can be summarized in the following points: The maximum garlic-clove discharges of 24, 22, 21 and 66 clove/metering-device revolution were obtained with metering device speed of 150 rpm(1.5 m/s)and agitator speed of 135 rpm(0.41 m/s)by using small, medium, large and random (mixed) clove-sizes respectively. The minimum garlic-clove damage was obtained with metering-device speed range of 50 -350 rpm(0.5 -3.6 m/s)and agitator speed of 85 rpm(0.26 m/s)using medium and large garlic-clove sizes of zero %.By increasing forward speed from 1.4 to 4.7 km/h plant-emergence percent decreased from 99.62 to 97.66 and from 99.93 to 99.76 %, double cloves decreased from 10.6 to 6.1 and from 4.2 to 4.1 %,the total crop yield decreased from 7.33 to 5.12 and from 8.67 to 6.22 Mg/fed using one and double grooved-rows, respectively. While, averages of garlic cloves spacing increased from 9.2 to 10.5 cm, missing hills increased from 0.21 to 1.77 and zero to zero %, under the same previous conditions.

The present study aims to enhance the performance of the rice grain-milling machines by using an attached primary cleaning-unit. The performance of the developed rice grain-milling machine was studied in terms of four different sieve shapes "CSS" of the attached primary cleaning unit ("A", "B", "C" and "D") with four different feeding rates (1.00, 1.25, 1.50 and 1.75 Mg/h) and four different primary cleaning sieve "PCS" speeds (310, 360, 420 and 470 rpm). The machine performance was depended on measuring machine productivity, machine efficiency, cleaning efficiency, total grain losses, required power, energy requirements and both operational and criterion costs. Results indicated that the best performance was yielded with the use of primary cleaning unit sieve shape "D" side by side with adjusting the feeding rate at 1.25 Mg/h and "PCS" speed at 360 rpm. Under these conditions values of machine productivity, machine and cleaning efficiencies were 1.20 Mg/h, 94.80 % and 96.90 % respectively. Meanwhile, the required power and energy requirements were 17.0 kW and 20.53kWh/Mg respectively. Finally, minimum operational and criterion costs were 43.18 and 94.52 LE/Mg, respectively.