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The aim of this investigation is to develop and evaluate a metering device for drilling wheat grains in hills. The developed metering device is a single sided flanged-disc with 4 cells. Three cell-sizes with 3-4, 5-6 and 7-8 grain/cell, four forward speeds of 2, 4, 6 and 8 km/h were investigated. The main results in this study can be summarized in the following points:The maximum seeding rate of 72.52 kg/fed was obtained at ground-wheel speed of 20 rpm or metering-device speed of 83.3 rpm and cell size of 7-8 grain/cell. Meanwhile, the minimum seeding rate of 34.39 kg/fed was obtained at ground-wheel speed of 60 rpm or metering-device speed of 333.3 rpm and cell size of 3-4 grain/cell.For designed metering device, the maximum wheat-grains germination of 100 % was obtained at ground-wheel speed of 20 rpm or metering-device speed of 83.3 rpm and cell size of 7-8 grain/cell. Meanwhile, the minimum wheat-grains germination of 98.7 % was obtained at metering-device speed of 60 rpm and cell size of 3-4 grain/cell.For designed metering device, the maximum wheat-plant emergence of 96.6 % was obtained at forward speed of 2 km/h and cell size of 7-8 grain/cell. Meanwhile, the minimum wheat-plant emergence of 90 % was obtained at forward speed of 8 km/h and cell size of 3-4 grain/cell.The optimum conditions clarify that the forward speed of 2 km/h had the best longitudinal seed distribution: average wheat hill-spacing of 11 cm, and CV of 5.4 %.The minimum missing-hills percent of 2.1 % was obtained with forward speed of 2 km/h. Meanwhile, the maximum missing-hills percent of 6.7 % was obtained with forward speed of 8 km/h.For designed metering device (hill drilling), the maximum wheat-grain yield of 3.465 Mg/fed (ton/fed) was obtained with forward speed of 2.0 km/h and cell size of 7-8 grain/cell. Meanwhile the minimum wheat-grain yield of 2.715 Mg/fed was obtained with forward speed of 8 km/h and cell size of 3-4 grain/cell. |
