What Is the Best Plant Growth Regulator Formulation for Your Crops in 2026?

Understanding Plant Growth Regulators: The Five Major Classes

Before diving into formulation science, it is essential to understand the active ingredients that formulators work with. There are five major classes of plant growth regulators, each with distinct functions and applications.

Auxins: The Rooting and Elongation Hormones

Auxins are best known for promoting cell elongation and root initiation. They are critical in shoot and root development, apical dominance, and tropic responses such as phototropism and gravitropism. Natural auxin includes indole-3-acetic acid (IAA), while synthetic auxins include indole-3-butyric acid (IBA), naphthaleneacetic acid (NAA), and 2,4-D. Common uses include rooting hormones for cuttings, preventing premature fruit drop, and selective weed control. Auxins help create more cells by stimulating cell division.

Gibberellins: The Stem Elongation Promoters

Gibberellins promote stem elongation, seed germination, flowering, and fruit development. They are especially important in breaking seed dormancy and stimulating growth in dwarf plants. The most common form is gibberellic acid (GA3). Uses include increasing fruit size, improving seed germination, inducing flowering, and lengthening stalks in certain crops. Gibberellins initiate various plant development processes.

Cytokinins: The Cell Division Regulators

Cytokinins stimulate cell division and delay leaf aging. They work closely with auxins to control organ formation and overall plant balance. Examples include zeatin, kinetin, and benzyladenine (BA). Uses include promoting shoot growth, enhancing tissue culture propagation, and extending the shelf life of leafy crops. Cytokinins help determine the role of various cells in plants. The cytokinin sub-segment is expected to hold the largest share of the PGR market, driven by their essential function in fostering cell division, shoot growth, and general plant development.

Abscisic Acid (ABA): The Stress Response Hormone

Abscisic acid is often called the stress hormone because it helps plants respond to drought, salinity, and other unfavorable conditions. It also regulates seed dormancy and stomatal closure. Its key role is slowing growth during stress conditions. Uses include improving drought tolerance and maintaining dormancy in seeds and buds.

Ethylene: The Ripening and Senescence Hormone

Ethylene is a gaseous plant hormone that influences fruit ripening, leaf abscission, flowering, and senescence. It is one of the most important regulators in postharvest management. Examples include ethylene gas and ethephon. Uses include ripening fruits, synchronizing flowering, and promoting uniform maturation in crops.

What Is Plant Growth Regulator Formulation?

Plant growth regulator formulation is the science and art of combining active PGR ingredients with carriers, solvents, surfactants, stabilizers, and other adjuvants to create a stable, effective, and user-friendly product that can be applied to crops.

As Jon Zuk, crop protection product manager for WinField United, explains: "The formulation of the PGR product is the key to having the right solution and source of PGRs in the plant". In fact, the ratio of individual PGRs in the plant and the formulation of solutions are so important that some companies hold patents related to these properties.

A well-designed plant growth regulator formulation ensures that the active ingredient remains stable during storage, disperses evenly when mixed with water, penetrates the plant surface effectively, and delivers the active compound to the target site in the plant at the right concentration and timing.

Types of Plant Growth Regulator Formulations

Plant growth regulators can be formulated in at least five different types of formulations: solutions, wettable powders, soluble powders, tablets, and water-soluble or dispersible granules. Based on formulation, the global PGR market is segmented into water-dispersible and water-soluble granules, wettable powders, and solutions.

Liquid Formulations: Solutions and Suspensions

Liquid formulations are the most widely used PGR formulation type. In Germany, liquid formulations accounted for 72.4% of the plant growth regulators market size in 2025 and were also the fastest-growing segment with an 8.7% CAGR through 2031.

Liquid formulations include soluble concentrates (SL), emulsifiable concentrates (EC), suspension concentrates (SC), and oil dispersions (OD). These formulations are easy to measure, mix, and apply through various methods such as foliar spray, soil drenching, or irrigation. With solutions, plant growth regulators can be easily mixed with water and applied through various methods, ensuring efficient and uniform distribution across crops.

However, due to their hydrophobic character and large molecular volumes, the production of highly stable emulsifiable concentrate formulations is often a bottleneck in plant growth regulator formulation.

Wettable Powders

Wettable powders (WP) are dry formulations that are mixed with water before application. They are particularly popular for oilseeds and pulses. In January 2025, Adama Agricultural Solutions launched a comprehensive range of wettable powder PGR formulations tailored for oilseeds and pulses, improving ease of application and compatibility with integrated pest management programs.

Water-Dispersible and Water-Soluble Granules

Water-dispersible granules (WG) and water-soluble granules (SG) offer the advantages of dry formulations — long shelf life, easy handling, and reduced transportation costs — combined with the convenience of liquid application. Granules comprise an active medium, a carrier medium, and optionally a surfactant.

Tablets

Tablet formulations are less common but offer precise dosing and convenient handling for specific applications.

Key Components of a Plant Growth Regulator Formulation

A successful plant growth regulator formulation requires careful selection and balancing of multiple components. Each component plays a specific role in ensuring the final product performs as intended.

Active Ingredients

The active ingredient is the PGR itself — the compound that produces the desired biological effect. Plant growth regulators may include gibberellins, auxins, organic acids, cytokinins, ethylene biosynthesis inhibitors, or combinations thereof. Many modern formulations combine multiple PGRs to achieve synergistic effects.

As Zuk explains, "The important thing is getting the ratio of the first three PGRs right when you develop a product. To get a positive response, the first three classes of compounds must be present in the ratio most beneficial to plants". This ratio-based approach to plant growth regulator formulation has been patented by some companies.

Solvents and Carriers

Solvents dissolve or disperse the active ingredient. Plant growth regulators are generally prepared by mixing the active ingredient with a solid carrier or a liquid carrier (diluent). Non-aqueous solutions use polar and/or semi-polar organic solvents. High concentration, low volatility solutions are an emerging trend in plant growth regulator formulation.

Surfactants and Adjuvants

Surfactants are used as wetting agents, as well as dispersing and granulating aids. They improve the spreading, wetting, and penetration of the formulation on plant surfaces. The surfactant may include carboxylates and other compounds. Non-ionic surfactants, such as polyol derivatives and sugar derivatives, can also serve as plant growth stimulating agents.

Adjuvants are compounds added to tank mixes or formulations to improve the properties and performance of the final pesticide formulation. Studies have shown that combining PGRs with adjuvants can achieve the same results as using full doses.

Stabilizers and Antioxidants

Many PGRs are unstable after application or during storage. Stabilizers and antioxidants are added to prevent degradation. The composition may further comprise an antioxidant such as propyl gallate, ethoxyquin, butylated hydroxyanisole, or butylated hydroxytoluene.

pH Adjusters and Buffers

pH adjusters and buffers maintain the optimal pH for stability and biological activity. Some formulations achieve exceptional stability through careful pH control.

The Science of Stable Plant Growth Regulator Formulation

Formulation stability is one of the greatest challenges in plant growth regulator development. Many PGRs have poor stability under environmental conditions, which leads to premature degradation and shortened biological activity.

Solubility Challenges

Many plant growth regulators are scarcely soluble and unstable in water. For example, 6-benzylaminopurine (6-BAP) shows considerable potential in agriculture, yet its practical use is hampered by low water solubility and susceptibility to light and heat instability. Conventional liquid formulation approaches such as soluble concentrate, emulsifiable concentrate, or suspension concentrate are often not possible due to low solubility of certain PGRs in solvents, including water.

Emulsion Stability

Highly stable oil-in-water emulsions with exceptional compatibility and outstanding emulsion stability can be created using secondary alcohol ethoxylates and sulfonate anionic surfactants in specific ratios. Some formulations have achieved storage stability for 12 months at 25°C.

Innovative Formulation Technologies

Researchers are developing innovative plant growth regulator formulations to address stability challenges. One promising approach is the use of onion-like lamellar liquid crystal structures, which provide robust stability even when encountering disturbances such as dilution, shaking, and changes in pH, ions, and temperature. This research provides an innovative pesticide formulation with eco-friendly adjuvants, less organic solvent, and synergistic functionalities.

Carrier-based smart delivery systems could be a better alternative to conventional PGR application methods such as spraying. Encapsulation of plant growth regulators is emerging as a strategy to boost their application for plant protection against abiotic stresses.

Application Methods for Plant Growth Regulator Formulations

The effectiveness of a plant growth regulator formulation depends not only on its composition but also on how it is applied. Different crops, growing conditions, and growth stages require different application methods.

In-Furrow Application

In-furrow applications are the current method of choice for achieving consistent results, particularly in corn. As Zuk notes, "Often you may be planting in cool, wet soil, and it's ideal if emerging roots access the PGR compound quickly". Four years of yield data from Answer Plots indicate a 3-bushel-per-acre advantage for PGR applied in-furrow versus no PGR.

Foliar Application

Foliar applications spray the PGR formulation directly onto plant leaves. If you are going to make a foliar application, choose a product designed for it. Some companies offer specific PGR formulations for foliar applications in all crops.

Soil Drenching and Irrigation

Soil drenching and application through irrigation systems ensure efficient and uniform distribution across crops.

2-by-2 Placement

2-by-2 placement can also work for PGR application. It is possible to see the benefit later with 2-by-2 placement, once roots access the PGR compound.

Emerging Trends in Plant Growth Regulator Formulation

The plant growth regulator formulation industry is evolving rapidly, driven by technological advancements, regulatory pressures, and changing farmer preferences.

Bio-Based and Organic Formulations

There is a growing emphasis on sustainable PGR formulations, with bio-based and organic options gaining popularity. These formulations are derived from natural sources. Key trends include bio-based PGRs, foliar spray innovations, and digital monitoring integration.

In April 2025, BASF SE launched a new line of bio-based plant growth regulators designed to enhance crop resilience and yield under climate stress conditions. The innovative formulations leverage natural plant extracts and biostimulants to promote sustainable farming practices.

In July 2024, Zhejiang Sega Science and Technology Co. Ltd launched A PANG, a plant growth regulator combining choline chloride and S-abscisic acid. This combination is designed to enhance photosynthesis and improve crop resilience, promoting better nutrient distribution and accelerating tuber expansion.

Precision Formulations and Customization

The market is witnessing a trend towards customized PGR solutions tailored to specific plant varieties and growing conditions. Precision farming uses sophisticated instruments and scientific procedures to enhance soil quality, raise productivity, and reduce labor costs. PGRs increase the activities of metabolic enzymes and the uptake of nutrients by roots, which in turn stimulates plant development. By lowering the demand for artificial agrochemicals, fertilizers, pesticides, and water, PGRs enable farmers to adopt sustainable farming techniques.

Next-Generation Formulations

In March 2025, Syngenta AG announced the commercial release of its next-generation synthetic auxin PGRs featuring improved efficacy and environmental safety profiles. In February 2025, UPL Limited expanded its portfolio with the introduction of a water-soluble gibberellin formulation designed for precision foliar application.

Nanoformulations and Encapsulation

Significant limitations such as chemical instability, rapid degradation, low release efficiency, and sensitivity to environmental factors reduce the performance of conventionally applied PGRs. Nanoformulations are being explored to promote more efficient, resilient, and environmentally sustainable agriculture. Micro- and nano-based formulations containing biostimulant molecules and microorganisms demonstrate several advantages over conventional formulations.

Challenges in Plant Growth Regulator Formulation Development

Developing effective plant growth regulator formulations is not without its challenges. Formulators must navigate a complex landscape of scientific, regulatory, and practical obstacles.

Chemical Instability

Many PGRs are inherently unstable, degrading rapidly when exposed to light, heat, or moisture. This instability can result in reduced biological activity and inconsistent field performance.

Low Solubility

Many PGRs have low water solubility, making it difficult to create stable liquid formulations. This often requires the use of organic solvents, which can raise environmental and regulatory concerns.

Regulatory Hurdles

Long approval timelines for new PGR formulations can delay market entry and hinder innovation. Formulators must demonstrate efficacy, safety, and environmental compatibility to obtain regulatory approval.

Application Consistency

Ensuring consistent performance across different crops, growing conditions, and application methods is a significant challenge.

Frequently Asked Questions About Plant Growth Regulator Formulation

What is a plant growth regulator formulation?

A plant growth regulator formulation is a carefully designed combination of active PGR ingredients with carriers, solvents, surfactants, stabilizers, and other adjuvants that creates a stable, effective, and user-friendly product for crop application. The formulation determines how the PGR is delivered, absorbed, and utilized by the plant.

What are the five major classes of plant growth regulators?

The five major classes are auxins, gibberellins, cytokinins, abscisic acid (ABA), and ethylene. Auxins promote cell elongation and root initiation. Gibberellins promote stem elongation and seed germination. Cytokinins stimulate cell division. ABA helps plants respond to stress. Ethylene influences fruit ripening and senescence.

What are the different types of plant growth regulator formulations?

Plant growth regulators can be formulated as solutions, wettable powders, soluble powders, tablets, and water-soluble or dispersible granules. Based on formulation, the market is segmented into water-dispersible and water-soluble granules, wettable powders, and solutions.

Why is formulation important for plant growth regulators?

Formulation is critical because it determines the stability, efficacy, and ease of use of the PGR product. A well-designed formulation ensures that the active ingredient remains stable during storage, disperses evenly when mixed with water, penetrates the plant surface effectively, and delivers the active compound at the right concentration and timing.

What are the key components of a PGR formulation?

Key components include the active ingredient (the PGR itself), solvents or carriers to dissolve or disperse the active ingredient, surfactants for wetting and spreading, stabilizers and antioxidants to prevent degradation, and pH adjusters to maintain optimal stability.

What is the most common type of PGR formulation?

Liquid formulations are the most widely used. In Germany, liquid formulations accounted for 72.4% of the PGR market in 2025. Liquid formulations are easy to measure, mix, and apply through various methods including foliar spray, soil drenching, and irrigation.

What are the challenges in PGR formulation?

Key challenges include chemical instability of many PGRs, low water solubility requiring organic solvents, long regulatory approval timelines, and ensuring consistent performance across different crops and conditions.

What is the difference between PGRs and fertilizers?

Fertilizers supply nutrients to plants. Plant growth regulators do not feed the plant. Instead, they regulate growth patterns such as cell division, elongation, flowering, dormancy, rooting, and fruit development. PGRs work at very low concentrations, while fertilizers are applied in much larger quantities.

How are PGR formulations applied to crops?

PGR formulations can be applied through various methods including foliar spray (spraying directly onto leaves), soil drenching, irrigation systems, in-furrow application during planting, and 2-by-2 placement beside the seed row.

What are bio-based PGR formulations?

Bio-based PGR formulations are derived from natural sources such as plant extracts, biostimulants, and beneficial microorganisms. They are gaining popularity as sustainable alternatives to synthetic PGRs. In April 2025, BASF launched a new line of bio-based PGRs leveraging natural plant extracts.

What is the market size for plant growth regulators?

The global PGR market was valued at approximately USD 3.5 to 5.2 billion in 2025 and is projected to grow significantly. Estimates vary, with some projecting growth from USD 5.75 billion in 2026 to USD 14.60 billion by 2034 at a CAGR of 12.36%. The market is driven by increasing food demand, sustainable agriculture initiatives, and precision farming adoption.

Can PGR formulations be combined with other crop protection products?

Yes. Many modern PGR formulations are designed for compatibility with integrated pest management programs. Studies have shown that combining PGRs with adjuvants can achieve the same results as using full doses. However, always check product labels and conduct compatibility tests before tank mixing.

What is the role of surfactants in PGR formulations?

Surfactants are used as wetting agents, as well as dispersing and granulating aids. They improve the spreading, wetting, and penetration of the formulation on plant surfaces, enhancing the effectiveness of the PGR.

What are the trends in PGR formulation development?

Key trends include bio-based and organic formulations, precision and customized solutions, next-generation synthetic PGRs with improved efficacy and safety profiles, nanoformulations and encapsulation technologies, and digital monitoring integration.

How do I choose the right PGR formulation for my crops?

Consider the plant species, desired growth response, duration of desired response, influence of environmental and cultural conditions, and time until shipping or sale. Consult with agronomists or crop advisors, review product labels, and consider conducting small-scale trials before full-field application. The formulation should match your application method and crop requirements.