Microelements are those essential elements which are required by the plants in concentration

Options

A. less than 10m mole/kg of dry matter.
B. less than 1m mole/kg of dry matter.
C. more than 1 `mu`g/g of dry matter.
D. equal to than 20`mu`g/ of dry matter

Answer

**Step-by-Step Solution:**

1. **Understanding Nutrient Types**:
- Plants require various nutrients for their growth, which are categorized into two main types: macronutrients and micronutrients.

2. **Definition of Micronutrients**:
- Micronutrients, also known as trace elements, are essential elements that plants need in very small amounts.

3. **Concentration of Micronutrients**:
- The concentration of micronutrients in plants is significantly lower than that of macronutrients. Specifically, micronutrients are required in concentrations of less than 1 mole per kg of dry matter.

4. **Comparison with Macronutrients**:
- In contrast, macronutrients are required in larger quantities, typically more than 1 mole per kg of dry matter.

5. **Conclusion**:
- Therefore, the correct answer to the question is that micronutrients are required by plants in concentrations of less than 1 mole per kg of dry matter.

---