Subtopic: Functional requirements, principles of working, construction and operation of manual, animal, tractor and renewable energy operated equipment for tillage, sowing, planting, fertilizer application, inter-cultivation, spraying, mowing, chaff cutting, harvesting and threshing
Question Statement:
Which of the following statements regarding the mechanical systems and operational characteristics of a self-propelled riding-type paddy transplanter is/are CORRECT?
Options:
(A) Rotary planting arms utilize an epicyclic gear train with eccentric/sun gears to produce an elongated pear-shaped picking and planting trajectory
(B) The seedling tray shifts laterally at the end of each stroke to feed the next column of nursery seedlings to the planting claw
(C) The push-out rod ejects the seedling mat chunk into puddled soil when the planting fork reaches its bottom-most dead center
(D) Paddy transplanters require standing water depths exceeding $15\text{ cm}$ for proper root anchoring and seedling uprightness
Answer Key:
A, B, C
Step-by-Step Solution & Explanation
- **Statement A is correct:** Planetary/epicyclic gear mechanisms inside the rotary planting case generate the characteristic pear-shaped kinematic locus required for claw entry, seedling separation, and vertical soil insertion.
- **Statement B is correct:** A cross-feed screw mechanism shifts the seedling tray incrementally sideways so that seedlings are picked uniformly from each mat strip.
- **Statement C is correct:** A cam-driven push-out fork forcefully ejects the seedling root block into the soft puddled soil at the lowest point of the trajectory.
- **Statement D is incorrect:** Excessive water depth (gt; 3\text{--}5\text{ cm}$) causes floating of transplanted seedlings and wash-out; field condition should be well-settled puddle with very shallow water ($1\text{--}2\text{ cm}$).