Which one of the following symptoms is not due to manganese toxicity in plants?

Options

A. Calcium translocation in shoot apex is inhibited
B. Deficiency in both iron and nitrogen is induced
C. Appearance of brown spots surrounded by chlorotic veins.
D. none of the above

Explanation

To answer the question "Which one of the following symptoms is not due to manganese toxicity in plants?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand Manganese Toxicity**:
- Manganese toxicity occurs when the concentration of manganese in the plant exceeds the optimal level required for growth. This excess can lead to various physiological disturbances in the plant.

2. **Identify Symptoms of Manganese Toxicity**:
- Common symptoms include:
- **Chlorotic veins**: This refers to the yellowing of the leaf veins while the surrounding tissue remains green.
- **Brown spots on leaves**: These are necrotic areas that develop due to the toxicity.
- **Inhibition of calcium translocation**: High levels of manganese can inhibit the movement of calcium to the shoot apex, affecting overall plant health.

3. **Analyze the Options**:
- **Option 1**: Calcium translocation in the shoot apex is inhibited. (This is true and a symptom of manganese toxicity.)
- **Option 2**: Deficiency in both nitrogen and iron is induced. (Manganese does interfere with iron uptake but does not induce nitrogen deficiency.)
- **Option 3**: Appearance of brown spots surrounded by chlorotic veins. (This is a characteristic symptom of manganese toxicity.)
- **Option 4**: None of the above. (This option is incorrect as we have identified symptoms.)

4. **Determine the Correct Answer**:
- The symptom that is **not** due to manganese toxicity is the **deficiency in both nitrogen and iron** (Option 2). Manganese primarily affects iron uptake but does not induce nitrogen deficiency.

### Final Answer:
The symptom that is not due to manganese toxicity in plants is **deficiency in both nitrogen and iron**.

---