Question

Most widely used chemicals for sugarcane ripening:
A. Ethrel
B. GA
C. Salicylic acid
D. Glyphosate
Choose the correct answer from the options given below:

• A. A and D only
• B. B and C only
• C. A and C only
• D. C and D only

Hint:

Low-dose Glyphosate is a "classic" ripener. It's a great example of how a herbicide at sub-lethal doses can act as a beneficial plant growth regulator (PGR).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Sugarcane ripening involves the conversion of stored starch or other carbohydrates into sucrose and its accumulation in the stalk. Chemical ripeners are substances that accelerate this process, allowing for earlier harvest and higher sugar recovery, especially in cool or wet weather.

Step 2: Detailed Explanation:
1. Ethrel (Ethephon) (A): Ethrel is a widely used ripener. It releases ethylene, which suppresses vegetative growth and redirects nutrients toward sucrose storage. It is highly effective in improving the sucrose percentage in early-matured stalks.
2. Glyphosate (D): Although primarily known as a broad-spectrum herbicide, low doses of glyphosate act as a chemical ripener in sugarcane. It inhibits the EPSPS enzyme, which slows down vegetative apical growth, thereby forcing the plant to store its photosynthetic products as sucrose in the internodes. This "growth-retarding" effect is highly beneficial for ripening.
3. GA (Gibberellic Acid) (B): GA is used to increase internode elongation and vegetative biomass in sugarcane (to increase tonnage), but it delays ripening because it promotes vegetative sink strength over sucrose storage.
4. Salicylic acid (C): It is involved in defense and thermogenesis but is not a standard commercial ripener for sugarcane.
Thus, A and D are the correct choices.

Step 3: Final Answer:
Ethrel and Glyphosate are the chemical ripeners used in sugarcane.