Question:
In tomato cultivation, which of the following is used for fruit set under adverse condition ?
In tomato cultivation, which of the following is used for fruit set under adverse condition ?
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PCPA (Para-chlorophenoxyacetic acid) is a highly stable synthetic auxin. In commercial tomato cultivation, spraying PCPA on flower clusters during extreme winter or summer months prevents flower drop and ensures a profitable off-season harvest.
Updated On: Jul 23, 2026
- GA3
- PCPA
- Kinetin
- IBA
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Verified By Collegedunia
The Correct Option is B
Solution and Explanation
Step 1: Understanding the Concept:
Tomato (Solanum lycopersicum) is a self-pollinated vegetable crop.
Successful fruit set in tomato is highly sensitive to environmental temperatures.
Extremely high (above $35^\circ\text{C}$) or low (below $15^\circ\text{C}$) temperatures cause pollen sterility, stigma drying, and poor pollen tube growth, resulting in pollination failure and severe blossom drop.
To overcome this physiological limitation, exogenous plant growth regulators are applied to induce parthenocarpic (seedless) fruit set under adverse weather conditions.
Step 2: Detailed Explanation:
Para-chlorophenoxyacetic acid (PCPA), a synthetic auxin, is widely used to promote fruit set in tomatoes under adverse environmental conditions.
Applying PCPA as a foliar spray or flower-cluster dip at concentrations of 20 to 50 ppm bypasses the requirement for natural pollination.
It triggers cell division and ovary wall expansion, inducing parthenocarpic fruit set and ensuring a consistent yield during off-season or extreme temperature periods.
Let us analyze the other options:
- GA3 (Gibberellic Acid): Although gibberellins can promote fruit elongation and set in some crops, they are not as effective or reliable as PCPA for commercial tomato fruit set under extreme temperatures.
- Kinetin: A cytokinin that primarily promotes cell division, but does not efficiently trigger parthenocarpic fruit set in tomatoes.
- IBA (Indole-3-butyric acid): An auxin primarily used in nursery management to promote rooting in cuttings, not for inducing fruit set.
Therefore, PCPA is the preferred auxin for tomato fruit set under adverse conditions.
Step 3: Final Answer:
The plant growth regulator used for fruit set under adverse conditions in tomato is PCPA.
Tomato (Solanum lycopersicum) is a self-pollinated vegetable crop.
Successful fruit set in tomato is highly sensitive to environmental temperatures.
Extremely high (above $35^\circ\text{C}$) or low (below $15^\circ\text{C}$) temperatures cause pollen sterility, stigma drying, and poor pollen tube growth, resulting in pollination failure and severe blossom drop.
To overcome this physiological limitation, exogenous plant growth regulators are applied to induce parthenocarpic (seedless) fruit set under adverse weather conditions.
Step 2: Detailed Explanation:
Para-chlorophenoxyacetic acid (PCPA), a synthetic auxin, is widely used to promote fruit set in tomatoes under adverse environmental conditions.
Applying PCPA as a foliar spray or flower-cluster dip at concentrations of 20 to 50 ppm bypasses the requirement for natural pollination.
It triggers cell division and ovary wall expansion, inducing parthenocarpic fruit set and ensuring a consistent yield during off-season or extreme temperature periods.
Let us analyze the other options:
- GA3 (Gibberellic Acid): Although gibberellins can promote fruit elongation and set in some crops, they are not as effective or reliable as PCPA for commercial tomato fruit set under extreme temperatures.
- Kinetin: A cytokinin that primarily promotes cell division, but does not efficiently trigger parthenocarpic fruit set in tomatoes.
- IBA (Indole-3-butyric acid): An auxin primarily used in nursery management to promote rooting in cuttings, not for inducing fruit set.
Therefore, PCPA is the preferred auxin for tomato fruit set under adverse conditions.
Step 3: Final Answer:
The plant growth regulator used for fruit set under adverse conditions in tomato is PCPA.
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