Flower drop and poor bud formation are emerging as common complaints this season across horticulture belts in India, particularly in vegetables, fruits, and commercial flowers. Agronomists and state agriculture advisories point to nutrient imbalance, weather stress, and improper spray timing as key reasons. The good news: targeted foliar sprays, when used at the right crop stage, are showing consistent improvement in flowering and fruit set. Instead of blanket spraying, experts now recommend crop- and stage-specific foliar nutrition, especially involving phosphorus, potassium, micronutrients, and plant growth regulators.
Below is a clear, field-tested guide on which foliar sprays actually increase flowering—and how to use them responsibly.
The Science Behind Flowering and Foliar Sprays
Flowering is a physiological process controlled by nutrient availability, plant hormones, and environmental conditions. When roots fail to absorb enough nutrients—due to soil moisture stress, high pH, or poor root activity—foliar application becomes effective.
Foliar sprays help by:
Delivering nutrients directly to leaves
Correcting temporary deficiencies quickly
Supporting bud initiation and retention
Improving pollen viability and flower strength
However, results depend on correct formulation, dosage, and crop stage.
Mono Potassium Phosphate (MKP): The Most Reliable Option
Mono Potassium Phosphate (00:52:34) is currently the most recommended foliar spray for improving flowering across crops.
Why it works
High phosphorus promotes flower initiation
Potassium improves bud strength and reduces flower drop
Chloride-free, safe for sensitive crops
Recommended use
Dose: 3–5 grams per litre of water
Stage: Pre-flowering or early bud initiation
Crops: Tomato, chilli, brinjal, grapes, citrus, cotton, pulses, flowers
Field insight
Extension officers report better bud uniformity and higher flower retention when MKP is sprayed 7–10 days before flowering.
Boron-Based Foliar Sprays: Essential for Flower Retention
Boron deficiency is a silent cause of poor flowering in many Indian soils, especially in light or alkaline soils.
Benefits of boron spray
Improves pollen formation
Reduces flower drop
Enhances fruit set after flowering
Common formulations
Solubor
Boric acid (food-grade for agriculture use)
Liquid boron formulations
Recommended use
Dose: 0.2–0.3% (2–3 grams per litre)
Stage: Early flowering
Frequency: One spray per cycle (avoid overuse)
Caution
Excess boron is toxic. Always follow label recommendations.
NPK Foliar Sprays (19:19:19 or 12:61:00)
Balanced NPK foliar sprays support plants during stress periods when flowering is delayed.
Best options
12:61:00 (high phosphorus) before flowering
19:19:19 during vegetative-to-reproductive transition
Recommended use
Dose: 5 grams per litre
Stage: 10–15 days before expected flowering
These sprays are particularly useful in vegetables and short-duration crops.
Plant Growth Regulators (PGRs): Use With Precision
Certain PGRs are proven to improve flowering, but misuse can damage crops.
Commonly used PGRs
NAA (Naphthalene Acetic Acid): Reduces flower drop
Triacontanol: Improves metabolic activity and flowering
Brassinosteroids: Enhance stress tolerance and bud initiation
General guidance
Always use at very low doses
Follow crop-specific recommendations
Avoid mixing multiple PGRs
Example
NAA at 10–20 ppm is widely used in fruit crops like mango and citrus to improve flowering and fruit retention.
Micronutrient Mixtures: The Supporting Role
Zinc, iron, manganese, and molybdenum play indirect but critical roles in flowering.
When to use
Visible deficiency symptoms
Known micronutrient-poor soils
Repeated flowering failure
Recommended use
Crop-specific micronutrient mixtures
Spray during pre-flowering stage
Do not mix with strong alkaline solutions
Best Practices for Foliar Sprays That Increase Flowering
To get consistent results, follow these operational rules:
Spray during early morning or late evening
Ensure fine mist coverage on leaves
Use clean water with neutral pH
Do not spray during extreme heat or rain
Maintain a gap of 7–10 days between sprays
Avoid unnecessary mixing of products
Foliar sprays work best as support tools, not substitutes for balanced soil nutrition.
Conclusion
There is no single “magic spray” for flowering. However, field data and extension recommendations clearly show that MKP (00:52:34), boron sprays, and stage-appropriate NPK foliar nutrition deliver reliable improvements when used correctly. The current shift in advisory focus is toward precision—right nutrient, right time, right dose. Farmers who align foliar spraying with crop stage and soil condition are seeing better flowering, stronger fruit set, and more predictable yields. Blind or excessive spraying, on the other hand, continues to cause avoidable losses. The priority now is informed, disciplined nutrient management—not experimentation.
