Auxin Chemistry and Crop Physiological Mechanisms
Alpha-Naphthyl Acetic Acid is a synthetic auxin that mimics natural indole-3-acetic acid (IAA). When applied at precise low concentrations, it prevents the premature formation of an abscission layer at the base of flower pedicels and fruit stalks.
This delayed abscission allows developing fruitlets to remain attached to the plant, increasing overall fruit retention.
- Prevents flower & fruit drop: Highly effective in chilli, tomato, mango, citrus, cotton, and pomegranate.
- Pineapple flowering: Induces uniform flowering and synchronized fruit ripening when applied during vegetative maturity.
- Fruit sizing: Enhances cell enlargement, resulting in superior fruit weight and market grading.
- Cotton boll retention: Minimizes square and boll shedding during sudden climatic fluctuations.
Dilution Precision and Spray Guidelines
Plant growth regulators must be measured with extreme accuracy; excessive concentrations can cause leaf epinasty, burning, or fruit thinning.
Applying during cool morning or evening hours ensures gradual absorption without rapid droplet evaporation.
- Follow label dilution guidelines meticulously, measuring in parts per million (ppm) or milliliters per liter of water.
- Apply using calibrated knapsack sprayers fitted with fine hollow cone nozzles.
- Never apply during extreme midday heat or drought stress to avoid temporary vegetative distortion.
Official source
Check the latest rules, benefits and forms here. KisanPe is an independent platform and is not a government website.
Central Insecticides Board & Registration Committee ↗Related on KisanPe
Common questions
What is the active ingredient in Aplin PGR?
Aplin contains Alpha-Naphthyl Acetic Acid (Alpha NAA), a synthetic plant growth regulator of the auxin family.
How does Alpha NAA prevent fruit drop in chillies and tomatoes?
It delays the formation of the abscission zone at the flower stalk base, keeping flowers and immature fruitlets firmly attached.
What happens if a farmer sprays an excessive dose of NAA PGR?
High concentrations act as a growth retardant or thinning agent, causing leaf curl, leaf dropping, or stunted vegetative growth.
General guidance, not personal advice. For your farm, ask your local Krishi Vigyan Kendra or agriculture officer.
More General Agriculture & Tools guides
Ask Sakhi AI in your language, check live mandi prices or plan a loan with KisanPe tools.