Question

33. Which of the following metering devices can be used for metering of single seeds
(A). Inclined plate
(B). Edge drop
(C). Vertical rotor
(D). Fluted roller
(E). Internal double run type
Choose the correct answer from the options given below:

• A. (A), (B) and (C) only
• B. (B), (C) and (D) only
• C. (C), (D) and (E) only
• D. (A), (D) and (E) only

Hint:

Precision planters (corn, cotton) use cell plate devices like inclined plate, edge drop, or vertical rotor to select individual seeds.
Standard seed drills (wheat, barley) use bulk flow devices like fluted roller or internal double run.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
A metering device in a planter or seed drill is responsible for regulating the flow of seeds from the hopper to the seed tube.
Seeding mechanisms are classified into two main types based on their distribution precision:
1. Precision planters: Select and place individual seeds at uniform intervals along the row (metering of single seeds).
2. Bulk seed drills: Continuous-flow metering devices that deliver a mass of seeds continuously along a furrow (volume-based metering).

Step 2: Detailed Explanation:
Let us evaluate each of the listed metering devices:
(A) Inclined plate: Features an inclined, rotating plate containing cell pockets around its outer edge.
Each cell picks up exactly one seed as it passes through the hopper and drops it down the seed tube, making it a highly reliable single-seed metering device for crops like corn, cotton, and peanuts.
(B) Edge drop: Uses a horizontal rotating plate with vertical cell pockets along its outer edge.
Seeds are positioned vertically (on edge) within the cells, ensuring only one seed occupies each cell to achieve single-seed metering.
(C) Vertical rotor: Uses a vertical disk with shaped cell recesses along its perimeter to select and transport single seeds before dropping them.
(D) Fluted roller: Consists of a fluted cylinder that rotates inside a feed cup, delivering a continuous stream of seeds.
It is designed for continuous bulk metering in standard grain drills (such as sowing wheat), and cannot meter individual seeds.
(E) Internal double run: A continuous bulk metering device containing a double-sided wheel used to sow crops of different seed sizes at high volumes, and is unsuitable for single-seed selection.
Therefore, only (A), (B), and (C) are single-seed precision metering devices.

Step 3: Final Answer:
The devices used for metering single seeds are (A), (B), and (C) only.