Question

Which of the following statements are INCORRECT about 'Enforced seed dormancy'?
• [(A).] Enforced seed dormancy occurs due to certain genetical and physiological factors. 
• [(B).] Enforced seed dormancy is truly a specific character of the seeds. 
• [(C).] High soil temperature and $NO_3$ content of the surface soil may help break the enforced seed dormancy. 
• [(D).] Cultivation practices may also break the enforced seed dormancy by exposing the seeds to better aeration. 
Choose the correct answer from the options given below: 
 

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

Hint:

To distinguish between dormancy types:
- Innate Primary: Internal genetic/physiological blocks (present when seed shed).
- Induced Secondary: Acquired block due to exposure to unfavorable conditions.
- Enforced: Simply waiting for favorable conditions (e.g., lack of water or light).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Seed dormancy is divided into three main types based on its cause: innate (primary), induced (secondary), and enforced dormancy.
Enforced dormancy (or environmental quiescence) is not an intrinsic property of the seed; rather, it is a state of inactivity caused entirely by unfavorable environmental conditions.

Step 3: Detailed Explanation:
Let us evaluate each of the statements to identify the incorrect ones:
- Statement (A) is INCORRECT: Enforced dormancy is caused by environmental limitations, such as a lack of water, oxygen, or light, or unfavorable temperatures.
It is not caused by internal genetic or physiological blocks within the seed itself (which define innate dormancy).
- Statement (B) is INCORRECT: Because enforced dormancy is imposed by external environmental factors, it is not an intrinsic biological characteristic of the seed.
If the seeds are placed in a favorable environment, they will germinate immediately.
- Statement (C) is correct: Environmental changes, such as high soil temperatures and increased nitrate (\(\text{NO}_3^-\)) concentrations in the surface soil, serve as signals that the seed is near the surface, breaking the enforced dormancy.
- Statement (D) is correct: Tillage and other cultivation practices bring buried seeds to the surface, exposing them to light and better aeration (oxygen), which breaks the enforced dormancy and triggers germination.
Therefore, statements (A) and (B) are incorrect.

Step 4: Final Answer:
The incorrect statements are (A) and (B) only, matching Option (A).