In plants a common symptom caused by deficiency of P, K, N and Mg is -

Options

A. Leaf tip hooking
B. Anthocyanin development
C. Necrosis/death of tissue
D. Poor formation of vascular tissue

Answer

### Step-by-Step Solution:

1. **Identify the Elements**: The question mentions the deficiency of four essential nutrients in plants: Phosphorus (P), Potassium (K), Nitrogen (N), and Magnesium (Mg). These are all macro-nutrients required in larger quantities by plants.

2. **Understand the Symptoms of Deficiency**: Each of these nutrients has specific deficiency symptoms. However, the question asks for a common symptom that arises from the deficiency of all four.

3. **Evaluate the Options**:
- **Option 1: Leaf tip hooking** - This symptom is typically associated with certain nutrient deficiencies but not specifically with P, K, N, and Mg.
- **Option 2: Anthocyanin development** - This is related to the accumulation of red and purple pigments in leaves, often due to nitrogen deficiency.
- **Option 3: Necrosis or death of tissue** - This refers to the degeneration of plant tissue, which can occur due to deficiencies in these nutrients.
- **Option 4: Poor formation of vascular tissue** - This symptom is primarily linked to Boron deficiency.

4. **Determine the Correct Answer**: Among the options, necrosis or death of tissue is a common symptom that can result from the deficiencies of Phosphorus, Potassium, Nitrogen, and Magnesium. This occurs because these nutrients are mobile within the plant, and their deficiency leads to tissue death in certain areas while the rest of the plant remains alive.

5. **Conclusion**: The correct answer to the question is **Option 3: Necrosis or death of tissue**.