• Broadcasting seed by hand over loose soil and covering them with some type of harrow was the common method of planting until about the middle of the 19^th Century.
• By that time some drills were made in Pannsylvania.
• The earliest row-crop planter patent was granted almost at the same time.
• One or two decades later the check-row planter was patented.
• The hill-drop attachment did not come into use until the 20^th Century.

We will see that planting equipment can be grouped in the following types

• Precision planters (row crop)
• Grain drills
• Broadcasters
• Potato planters
• Vegetable planters

• Planters can give different types of precision and distribution patterns depending upon which of the following machines is being used.
• Regular drill planter
• Check-row planter
• Hill drop planter

• 1 In the regular drill-planter, the seeds are individually picked from the hopper by a circular plate and they are released in the shank to be delivered by gravity to the bottom of the furrow, Figure 2. With this planter the bouncing of seeds against the shank and the soil creates some variability in the seed spacing.

• In check-row planting, plants line up crossways for cross-cultivation. It facilitates weed control in wet years when weeds may get as high as the corn before the first cultivation is possible.
• Chemical weed control has reduced the need for check-row planting to control weeds.
• The check-row planter picks the seed from the hopper in the same way the regular drill does, but they are accumulated in the shank valve before being deposited in the furrow. The valve is operated by a check-wire which is held at the ends of the field by two anchor stakes, Figure 1.
• Every time the operator reaches the end of the field, he has to turn the tractor into the next row, move the anchor stake and place the wire in the check head.
• A serious disadvantage of check-row planting is the extra time required to handle the wire and move the stakes.
• With the advent of quick-hybrid corn, high application rates of starter fertilizer, and chemical weed control, the cross cultivation advantage is now not very important.

• It is a check-planter using an automatic valve tripping mechanism instead of check-wire. It offers the same advantages of check planting without presenting the greatest disadvantage of the extra time and labor required for planting. Hill-drop and check planters must be equipped with valves. The upper, located immediately below the seed plate, collects the number of kernels for one hill.
• The lower valve, located just above the soil surface in the boot, re-groups the kernels and ejects them into the furrow, Figure 10.
• Recent design developments in corn planters have replaced the double valve by a rotary valve, Figure 11.
• The new designs are intended to give improved hill dropping performance at speeds of six MPH, and reduce the number of moving parts.
• For all types of planters we have seen up to now, there are some components that are common to all of them with some minor differences.
• Metering device (hoppers)
• Seed delivery mechanism
• Furrow openers and covers
• Press wheels

• The most popular hoppers being used for corn, cotton, beans etc., are:
• Richmond hopper (specially for corn)
• Single seed cotton hopper
• Reserve-seed cotton hopper
• Duplex hopper (all seeds except cotton)