Which of the following statement is not correct for criteria for essentiality of an element ?

Options

A. The element must be directly involved in the metabolism of plant
B. In absence of the element the plant cannot complete their life cycle
C. The requirement of element must be specific and not replaceable by another element
D. The element must be absolutely necessary for supporting normal growth and not for reproduction

Answer

To determine which statement is not correct regarding the criteria for the essentiality of an element in plants, we can analyze each option based on the established criteria set by Arner and Stout in 1937.

### Step-by-Step Solution:

1. **Understanding Essential Elements**: Essential elements are those that are required for the growth and development of plants. They must meet specific criteria to be classified as essential.

2. **Analyzing Each Option**:
- **Option A**: "Element must be directly involved in the metabolism of plant."
- This statement is **correct**. An essential element must play a direct role in the plant's metabolic processes.

- **Option B**: "In the absence of an element, the plant can't complete their life cycle."
- This statement is also **correct**. If an essential element is missing, the plant will not be able to complete its life cycle, indicating its necessity.

- **Option C**: "Requirement of element must be specific not replaceable by another element."
- This statement is **correct**. An essential element must have a specific role that cannot be fulfilled by another element; otherwise, it would not be considered essential.

- **Option D**: "Element must be absolutely necessary for supporting normal growth and not for reproduction."
- This statement is **not correct**. Essential elements are required for both growth and reproduction, not just for growth. Therefore, this option does not meet the criteria for essentiality.

3. **Conclusion**: The statement that is not correct regarding the criteria for essentiality of an element is **Option D**.

### Final Answer:
**Option D**: "Element must be absolutely necessary for supporting normal growth and not for reproduction."