Which is not a chelating agent in mineral nutrition :

Options

A. EDTA,Citric Acid
B. EDDHA,Caffic acid
C. Siderophores,Trataric
D. EDB,Humic acid

Answer

### Step-by-Step Solution:

1. **Understand the Concept of Chelating Agents**:
- A chelating agent is a molecule that can form multiple bonds with metal ions. This allows the chelating agent to hold the metal ion tightly, which is important for mineral nutrition in plants.

2. **Function of Chelating Agents**:
- Chelating agents help in reducing the deficiency of specific minerals by binding to metal ions and slowly releasing them for plant uptake.

3. **Identify Common Chelating Agents**:
- Examples of common chelating agents include:
- **EDTA (Ethylene Diamine Tetraacetic Acid)**: A well-known chelating agent.
- **EDDHA (Ethylene Diamine Dihydroxy Phenyl Acetic Acid)**: Another effective chelator.
- **Siderophores**: These are compounds that chelate iron ions, essential for plant growth.

4. **Analyze the Options Given**:
- The question asks for an option that is NOT a chelating agent.
- The options include EDTA, EDDHA, siderophores, tartaric acid, and humic acid.

5. **Evaluate Each Option**:
- **EDTA**: A chelating agent.
- **EDDHA**: A chelating agent.
- **Siderophores**: A chelating agent for iron.
- **Tartaric Acid**: While it can have some chelating properties, it is not primarily recognized as a chelating agent.
- **Humic Acid**: Generally does not function as a chelating agent.

6. **Conclusion**:
- The correct answer to the question "Which is not a chelating agent in mineral nutrition?" is **humic acid**.

### Final Answer:
Humic acid is not a chelating agent in mineral nutrition.

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