الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The metering mechanisms must work effectively in order to continuously meter seed at a uniform rate and space with respect to the ground surface and speed. In additional, It should metered the seeds with less damage and there are many problems happen when using metering devices on planting such as longitudinal scattering and uncultivated spaces at rows so, this work was concentrated on developed a new metering device provided with an electronic circuit has engineering parameters suitable for seeds and overcome the above problems in available planting machines The developed metering device had three engineering considerations to protect seed against mechanical damage, there are :- 1- the bottom of seed hopper was covered with silicone material to reduce the grain impact damage. 2- the teeth of metering disc was covered with plastic to overcome grain damage 3- sloping barrier was designed on main hopper to make grain sliding easily to developed the new metering device , and evaluate its performance there were group of experiments were carried out : - the first experimental group : - it was carried out in laboratory to measuring the physical and mechanical properties of the tested corn grains to can introduce the most suitable engineering parameters for design and developing planter metering device the second experimental group :- it was conducted in laboratory also, to evaluate the developed metering device under four reduction ratio speed for feeding shaft (24, 34, 46,65) r.p.m the third experimental group : - it included the field experiments under different operating of field conditions.