Spraying sugarcane with gibberellins increases the yield by as much as 20 tonnes per acre. GA performs it by

Options

A. inproving the quality of fruit
B. increasinf sugar content
C. Internodal elongation
D. delaying senescence.

Answer

To answer the question regarding how gibberellins (GA) increase the yield of sugarcane by as much as 20 tonnes per acre, we can break down the explanation into a series of steps:

### Step-by-Step Solution:

1. **Understanding Gibberellins**: Gibberellins are a group of plant hormones that play a crucial role in regulating various growth processes in plants, including stem elongation, seed germination, and flowering.

**Hint**: Remember that gibberellins are plant hormones that influence growth and development.

2. **Function of Gibberellins in Sugarcane**: In sugarcane, gibberellins specifically stimulate internodal elongation. This means that they promote the growth of the sections between the nodes (the joints of the stem).

**Hint**: Focus on the term "internodal elongation" as it is key to understanding how gibberellins affect sugarcane growth.

3. **Impact of Internodal Elongation**: The elongation of internodes leads to taller sugarcane plants. Taller plants can capture more sunlight and have a larger biomass, which contributes to increased overall yield.

**Hint**: Think about how taller plants might have advantages in terms of sunlight and space.

4. **Evaluating the Options**: The question provides four options regarding how gibberellins increase yield:
- A) Improving the quality of fruit
- B) Increasing sugar content
- C) Internodal elongation
- D) Delaying senescence

Among these options, the most relevant to the action of gibberellins in sugarcane is **C) Internodal elongation**.

**Hint**: Compare each option with the role of gibberellins to identify the most accurate one.

5. **Conclusion**: Therefore, the correct answer to the question is that gibberellins increase the yield of sugarcane primarily through **internodal elongation**.

**Hint**: Summarize the key points to reinforce your understanding of how gibberellins function in increasing sugarcane yield.

### Final Answer:
Gibberellins increase the yield of sugarcane by stimulating **internodal elongation**.