The Modern Planter
Corn kernels vary considerably in size and shape depending on the part of the cob on which they grow. To plant corn with precision, the cells that meter the corn must be the same size and shape as the corn seed. To accomplish this, seed corn is graded into standard sizes described as small, medium and large; round or flat. The plate corn planter has exchangeable seed plates that can be selected to match the seed.
Modern corn planters can be adapted to sow at several row widths and at a wide variety of seed spacings, determined by the variety of corn, growing conditions and harvesting equipment. Attachments to apply granular insecticides and herbicides in bands over the row are available. Recently corn planters which meter seed pneumatically have been developed. Ungraded seed can be used with these planters for a considerable saving in the cost of seed.
In the future we may see planters that will place in the soil a degradable ribbon incorporating seed, starting fertilizer and insecticide, ready to be released at rates and in amounts for optimum performance.