Detailed Comparison Of 5 Common Plant Growth Regulators In Vietnam

In modern agriculture, Plant Growth Regulators (PGRs) are like biological “control systems” that help guide plant development in the desired direction — from regulating plant height and inducing flowering to improving fruit set and preventing fruit drop.

Below is a quick comparison of five widely used PGRs and their practical applications in Vietnam:

1. Mepiquat chloride

• Group: Quaternary ammonium
• Mode of action: Inhibits GA synthesis
• Main effects: Reduces plant height, prevents lodging, promotes flowering, increases fruit set
• Pros: Stable performance, easy to control
• Cons: Moderate efficacy
• Common formulation: 25–50% SL
• Systemicity: Moderate (absorbed through leaves)
• Applications: Field crops, fruit trees, ornamental plants

2. Chlormequat chloride

• Group: Quaternary ammonium
• Mode of action: Inhibits GA synthesis
• Main effects: Controls height, prevents lodging, stimulates flowering
• Pros: Affordable, widely available
• Cons: Low efficacy, risk of leaf burn if overdosed
• Common formulation: 50% SL
• Systemicity: Weak
• Applications: Cereal crops, ornamental flowers

3. Paclobutrazol

• Group: Triazole
• Mode of action: Inhibits GA biosynthesis
• Main effects: Induces flower bud differentiation, suppresses vegetative growth, strengthens stems, triggers off-season flowering
• Pros: Highly effective for fruit trees
• Cons: Persistent in soil, may affect following crops
• Formulation: 15–25% SC or WP
• Systemicity: Very strong (absorbed through roots and leaves)
• Applications: Fruit trees, bonsai and ornamental plants

4. Uniconazole

• Group: Triazole
• Mode of action: Inhibits GA + ABA synthesis
• Main effects: Similar to Paclobutrazol but more potent and easier to dose accurately
• Pros: Strong efficacy at low doses
• Cons: High cost, long residual period
• Formulation: 5–10% SC
• Systemicity: Very strong
• Applications: Widely used on fruit trees and ornamentals

5. Brassinolide

• Group: Natural brassinosteroid
• Mode of action: Stimulates natural hormone activity
• Main effects: Improves fruit set, reduces premature fruit drop, enhances stress resistance
• Pros: Very safe, supports overall plant development
• Cons: Does not inhibit growth
• Formulation: 0.01–0.1% SL
• Systemicity: Weak
• Applications: Fruit trees, field crops, vegetables, ornamentals, industrial crops

Summary:

• If you need growth suppression and off-season flowering, Paclobutrazol and Uniconazole are top choices.
• For comprehensive plant development, stress resistance, and fruit set, Brassinolide is ideal.
• If you're looking for a cost-effective, simple solution, Mepiquat chloride or Chlormequat chloride will suffice.

Note: Each PGR has its own strengths and weaknesses. The key to success is choosing the right product, using the correct dose, and applying it at the right time.

Which PGRs are you currently using? Have you encountered challenges using them? Share your experience in the comments!