Photoperiodic induction can be produced

Options

A. when certain minimum vegetative growth has taken place
B. when vegetative growth completely stops
C. when plant reaches certain specific height
D. irrespective of any of the above conditions

Answer

To solve the question "Photoperiodic induction can be produced," we will analyze the options provided and determine which condition allows for photoperiodic induction to occur.

### Step-by-Step Solution:

1. **Understanding Photoperiodic Induction**:
- Photoperiodic induction refers to the process by which plants detect the length of day and night to trigger flowering. This process is influenced by the duration of light exposure (photoperiod) that a plant receives.

2. **Analyzing the Options**:
- **Option 1**: "When certain minimum vegetative growth has taken place."
- This option suggests that a certain level of vegetative growth is necessary for photoperiodic induction. This is correct because plants need to reach a certain stage of growth before they can respond to photoperiod cues for flowering.

- **Option 2**: "When vegetative growth completely stops."
- This option is incorrect. If vegetative growth has completely stopped, the plant may not be in a suitable state to respond to photoperiodic cues for flowering.

- **Option 3**: "When the plant reaches a certain specific light."
- This option is somewhat vague but implies that specific light conditions are necessary. While light is indeed crucial for photoperiodic induction, this option does not specify the necessary vegetative growth stage, making it less accurate.

- **Option 4**: "Irrespective of any of the above conditions."
- This option is incorrect because photoperiodic induction is dependent on certain conditions, including vegetative growth and light exposure.

3. **Conclusion**:
- Based on the analysis, the correct answer is **Option 1**: "When certain minimum vegetative growth has taken place."