Question

The chemical used to induce uniform flowering in pineapple is

• A. Paclobutrazol
• B. Naphthalene Acetic Acid
• C. 2,4,5-Trichlorophenoxyacetic acid
• D. trans-zeatin

Hint:

Uniform flowering in pineapple is classically induced by the application of auxins like NAA or ethylene-releasing compounds like Ethephon.
This is a standard practical application of phytohormones in commercial agriculture.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Synthetic plant growth regulators are widely used in commercial agriculture to synchronize developmental stages, enhance crop yields, and facilitate mechanized harvesting.
In pineapple cultivation, promoting uniform and synchronous flowering is essential to ensure that the entire crop ripens at the same time.

Step 2: Detailed Explanation:
Let us review the agricultural applications of the listed chemicals in relation to pineapple flowering:
1. Auxins and Ethylene in Pineapple: Pineapple is a unique crop where exogenous application of auxins or ethylene triggers uniform flowering.
When auxins are applied to the pineapple canopy, they stimulate the biosynthesis of ethylene in the plant tissue, which acts as the direct trigger for floral induction.
2. Naphthalene Acetic Acid (NAA) (B): NAA is a synthetic auxin that is highly effective for this purpose.
Applying low concentrations of NAA to pineapple crops promotes synchronized flowering across the entire field.
This uniform flowering allows for a single, efficient, mechanized harvest, minimizing labor costs.
3. Paclobutrazol (A): This is a gibberellin biosynthesis inhibitor used to restrict vegetative growth and promote flowering in fruit trees like mango, but it is not the primary agent for pineapples.
4. 2,4,5-T (C): This is a chlorinated phenoxy herbicide and synthetic auxin that is highly toxic and banned in most countries.
5. trans-zeatin (D): This is a natural cytokinin that promotes cell division and lateral bud growth but does not induce uniform flowering in pineapples.

Step 3: Final Answer:
The synthetic auxin used to induce uniform flowering in pineapple is Naphthalene Acetic Acid, which corresponds to option (B).