Deficiency of which of the following can casue yellowing of intravenous regions of leaves?

Options

A. Calcium
B. Potassium
C. Copper
D. Phosphorus

Answer

To solve the question about which deficiency can cause yellowing of the interveinal regions of leaves, we will analyze the effects of each nutrient mentioned in the options: calcium, potassium, copper, and phosphorus.

### Step-by-Step Solution:

1. **Understanding the Question**:
- The question asks which nutrient deficiency leads to yellowing specifically in the interveinal areas of leaves.

2. **Analyzing Each Nutrient**:
- **Calcium**:
- Calcium is essential for cell wall synthesis. A deficiency in calcium typically results in stunted growth and necrosis of root tips and young leaves, but it does not specifically cause yellowing of the interveinal areas.

- **Potassium**:
- Potassium is crucial for various plant functions, including osmoregulation and enzyme activation. A deficiency of potassium leads to scorched leaf tips, shorter internodes, and importantly, chlorosis (yellowing) of the interveinal areas. This is a key point that aligns with the question.

- **Copper**:
- Copper is involved in photosynthesis and respiration. Its deficiency can cause necrosis at the tips of young leaves, but it does not specifically cause yellowing of the interveinal areas.

- **Phosphorus**:
- Phosphorus is important for energy transfer and photosynthesis. A deficiency in phosphorus can lead to premature leaf falling, but again, it does not cause yellowing of the interveinal regions.

3. **Conclusion**:
- Based on the analysis, the nutrient whose deficiency causes yellowing of the interveinal regions of leaves is **Potassium**.

### Final Answer:
- The correct answer is **Potassium**.