This research was performed to determine the effect of different operating parameters on seed holding in a single seed metering unit. The metering unit was a vertical seed plate with a vacuum, used in seeding maize (Zea mays L.). An electronic counter in the metering unit was used to determine the holes without seed on the plate holes. The shapes of the holes, peripheral velocities, vacuum pressure, hole area on the seed plate and thousand grain weight of seed (TGW) were chosen as the operating parameters. A Factorial Completely Randomized Design was used for analysis of variance, Duncan's multiple range test and mean comparison. The data were analyzed using the MSTAT-C statistics program. At the end of the research, it was found that the hole's shape, peripheral velocity, vacuum pressure, the hole area and thousand grain weight of seed had an effect on the seed holding ratio (SHR) at a significance level of 1% (P < 0.01). The most suitable shape of the holes in the seed plate was oblong for maize seeds. The seed holding ratio decreased when the peripheral velocity of the seed plate increased, whereas the seed holding ratio increased parallel to the increase in vacuum pressure. An increase in the thousand grain weight of seed necessitated a larger hole area for holding seeds on the plate holes.

This research was performed to determine the effect of different operating parameters on seed holding in a single seed metering unit. The metering unit was a vertical seed plate with a vacuum, used in seeding maize (Zea mays L.). An electronic counter in the metering unit was used to determine the holes without seed on the plate holes. The shapes of the holes, peripheral velocities, vacuum pressure, hole area on the seed plate and thousand grain weight of seed (TGW) were chosen as the operating parameters. A Factorial Completely Randomized Design was used for analysis of variance, Duncan's multiple range test and mean comparison. The data were analyzed using the MSTAT-C statistics program. At the end of the research, it was found that the hole's shape, peripheral velocity, vacuum pressure, the hole area and thousand grain weight of seed had an effect on the seed holding ratio (SHR) at a significance level of 1% (P < 0.01). The most suitable shape of the holes in the seed plate was oblong for maize seeds. The seed holding ratio decreased when the peripheral velocity of the seed plate increased, whereas the seed holding ratio increased parallel to the increase in vacuum pressure. An increase in the thousand grain weight of seed necessitated a larger hole area for holding seeds on the plate holes.