What Is Chlormequat and How Does It Regulate Plant Growth?

Technical Introduction

Chlormequat, commonly used in its chloride form (chlormequat chloride, formula C₅H₁₃Cl₂N), is a quaternary ammonium compound that acts as a plant growth regulator (PGR).
It appears as a colorless to pale yellow liquid (often supplied as an aqueous solution) and is highly soluble in water.
Its primary function is to inhibit gibberellin biosynthesis, leading to shorter, sturdier plants with improved lodging resistance.

Originally developed for use in cereals and ornamental plants, chlormequat remains a widely applied tool in modern crop management for both yield protection and aesthetic control.

Applications

1. Agriculture

• Lodging Prevention in Cereals: Shortens stem elongation in wheat, barley, oats, and rye.

• Improved Harvestability: Shorter, stronger stems improve mechanical harvesting efficiency.

• Flowering Control: In some crops, enhances uniform flowering and fruit set.

2. Horticulture

• Used in ornamental plants (e.g., poinsettia, chrysanthemums) to control plant height and improve shape.

3. Plant Physiology Research

• Investigates gibberellin-related growth processes.

Advantages

• Effective at Low Doses: Economical for large-scale use.

• Water-Soluble: Easy to prepare and apply.

• Versatile: Works across a variety of crop and ornamental species.

Typical Parameters

FAQs

Q1: Is chlormequat safe for humans?
A1: It is classified as slightly toxic; avoid inhalation and skin contact. Strictly follow agricultural safety guidelines.

Q2: Does it affect yield?
A2: While it shortens plant height, it typically maintains or increases yield by preventing lodging losses.

Q3: Can it be tank-mixed with other PGRs or pesticides?
A3: Often yes, but compatibility testing is recommended before large-scale use.

Q4: How quickly does it act?
A4: Effects on stem elongation are noticeable within days to weeks, depending on crop and environmental conditions.

Q5: Is it environmentally persistent?
A5: It degrades in soil and water over time, but careful management is still required to prevent runoff.