Farm Power And Machinery (1+1)

Planters

Planter is normally used for those seeds which are larger in size and can not be sown by usual seed drills.
The main functions of the planter are:

• To open the furrow
• To meter the seed
• To deposit the seed in the furrow
• To cover the seeds and compact the soil over it.
Parts of a planter
A planter consists of hopper, seed metering device, knock out arrangement, cut-off mechanism, furrow opener and other accessories.

Hopper

A planter has seed hopper for each row. Hopper is usually made of mild steel or any other suitable material.

Seed metering device in a planter

There are a number of seed metering devices in a planter but the most common device consist of a rotating plate at the bottom of seed hoppers. In some planters, vertical rotors as well as inclined rotors are also used.
The most common is the horizontal seed plate used in planters. The horizontal seed plates have got suitable notches or holes called cell. Depending upon the type of notches on the plates, it is of three types.

(i) Edge drop
(ii) Flat drop
(iii) Hill drop.

The edge drop carries the seed on edge in the cell of the plate. The flat drop carries the seed on a flat in the cell of the plate. Only one seed is allowed in the cell at each time. In hill drop, the cells round the edge of the plate are large enough to admit several seeds at a time.
The rotating plate receives the seeds from the hopper.

Cut off mechanisms

The plate moves under an arrangement called cut-off which allows only those seeds which are accommodated in the cells. Cut-off mechanism cuts-off or brushes out excess seeds from the cells of the feed mechanism.

Knock out arrangement

This mechanism is a device which knocks out the seeds from the cells or picker heads of the mechanism. It consists of rollers, star wheels or rounded points which are forced into the cells by the pressure of a spring and eject seeds out of the cells.
The spacing of seeds or hills in the row is determined by the ratio of linear or peripheral speed of the cells to the forward speed of the planter and by the distance between the cells in the metering unit.
The accuracy of the planter depends upon several factors such as:

(i) speed of seed plate
(ii) shape and size of cells
(iii) shape of hopper bottom and
(iv) uniformity of seed size.

Planter is usually used for those seeds which are required to be sown at equal intervals between plant to plant.