Moderate increase in the requirement of trace elements induces:

Options

A. Balancing effect
B. Osmotic effect
C. Toxic effect
D. Neutralising effect

Answer

To answer the question "Moderate increase in the requirement of trace elements induces:", we can break down the concepts involved in mineral nutrition, particularly focusing on trace elements.

### Step-by-Step Solution:

1. **Understanding Trace Elements**: Trace elements (or microelements) are essential nutrients required by plants in very small amounts. Examples include iron, manganese, zinc, copper, molybdenum, and boron.

2. **Deficiency of Trace Elements**: When there is a deficiency of these trace elements, it can lead to various metabolic disorders in plants. These disorders can affect growth, development, and overall health.

3. **Excess of Trace Elements**: Conversely, if there is an increase in the requirement or availability of these trace elements, it can lead to toxicity. This means that while the plants need these elements, too much of them can be harmful.

4. **Moderate Increase**: The question specifies a "moderate increase" in the requirement of trace elements. This suggests that while the increase is not extreme, it is still significant enough to potentially lead to negative effects.

5. **Conclusion**: Therefore, a moderate increase in the requirement of trace elements induces toxicity in plants. This toxicity can manifest in various ways, such as impaired growth, chlorosis, or other physiological disturbances.

6. **Final Answer**: The correct answer is that a moderate increase in the requirement of trace elements induces toxicity.