Soil-less culture helps to know

Options

A. toxicity caused by an element
B. deficiency symptoms caused by an element
C. Essentiality of element
D. all of the above

Answer

### Step-by-Step Text Solution:

1. **Understanding Soil-less Culture**: Soil-less culture, also known as hydroponics, is a method of growing plants without soil. Instead, plants are grown in a nutrient solution that provides all the essential minerals and nutrients they need for growth.

2. **Identifying the Purpose of Soil-less Culture**: The primary purpose of soil-less culture is to study various aspects of plant nutrition and growth. This includes understanding how different elements affect plant health.

3. **Essentiality of Elements**: Soil-less culture helps in determining the essentiality of mineral elements. Certain elements such as nitrogen, phosphorus, and potassium are crucial for plant growth. Hydroponics allows researchers to observe the effects of these elements on plant development.

4. **Deficiency Symptoms**: By using soil-less culture, researchers can also identify deficiency symptoms that occur when a specific nutrient is lacking. For instance, if a plant does not receive enough nitrogen, it may exhibit yellowing of leaves, known as chlorosis.

5. **Toxicity of Elements**: Soil-less culture is useful for studying the toxicity caused by excess elements. When certain nutrients are present in high concentrations, they can be harmful to plants, leading to symptoms like leaf burn or stunted growth.

6. **Conclusion**: Therefore, soil-less culture helps in understanding toxicity caused by an element, deficiency symptoms caused by an element, and the essentiality of elements. Thus, the correct answer is "all of the above."