Excess of manganese may induce the deficiencies of

Options

A. Iron
B. Calcium
C. Magnesium
D. All of these

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the effects of excess manganese on the deficiencies of other minerals in plants.

2. **Identifying the Key Minerals**: The options provided are:
- Iron
- Calcium
- Magnesium
- All of these

3. **Role of Manganese**: Manganese is an essential micronutrient for plants, but in excess, it can be harmful. It can interfere with the absorption of other essential minerals.

4. **Impact on Iron**: One of the primary effects of excess manganese is the inhibition of iron uptake. Iron is crucial for chlorophyll production, and its deficiency leads to a condition called chlorosis, which is characterized by yellowing of leaves due to insufficient chlorophyll.

5. **Soil Conditions**: Excess manganese often occurs in waterlogged or over-fertilized soils, which can lead to an imbalance of nutrients. In such conditions, even if iron is present in the soil, plants may not be able to absorb it effectively.

6. **Conclusion**: Based on the information, the excess of manganese primarily induces the deficiency of iron. While calcium and magnesium can also be affected, the most direct and significant impact noted in the context provided is on iron.

7. **Final Answer**: Therefore, the correct answer to the question is that excess manganese may induce the deficiencies of **iron**.