Lawn care specialists have utilized plant growth regulators (PGRs) for a number of years to assist in the maintenance of a strong healthy lawn by regulating the rate of vertical grass growth while promoting deeper root development and turf density, thus improving the resilience of lawns and sports fields and increasing their aesthetic qualities. To achieve a well-balanced turf, the combination of proper nutrient levels and managed growth is necessary. 

Plant growth regulators have a significant role in achieving balanced nutrients and controlled turf growth. Plant growth regulators regulate plant hormone activity and assist grass in utilizing its water and nutrients effectively, reduces stress associated with the frequency of mowing, and provides consistent coloration and texture of lawn grasses during the growing season.

Utilization of growth regulators along with an appropriate PGR fertilizer will also help develop healthy long-term turfs through increased root strength, decreased thatch accumulation, and overall durability of the grass plant. PGR usage on grasses provides a positive and sustainable lawn management option for residential homes, golf courses, and public landscape areas.

Understanding PGR for Grass in Modern Agriculture

In addition to maximizing crop production through better yields, maintaining healthy and uniform turf is as critical for successful agricultural production as maximizing crop production through better yields. 

PGRs (Plant Growth Regulators) for Grass help maintain the desired balance of a healthy, dense lawn and at the same time to establish healthy turfgrass. PGRs achieve this desired balance by influencing the manner in which grass grows and develops

What Are Plant Growth Regulators (PGRs)?

Plant Growth Regulators (PGRs) are compounds that can modify the plant's hormone system and alter its growth and development by manipulating the plant's hormone system to control the direction and speed of growth and development.

Characteristics of PGRs can be divided into four key categories;

• Regulate vertical and lateral shoot and root growth
• Control uncontrollable vertical growth
• Improve the efficiency of the plant's use of nutrient and moisture
• Increase the plant's ability to tolerate environmental stresses such as heat, drought, and mowing

Developing a Plant Growth Regulator (PGR)

Instead of just providing plant nutrients with traditional fertilizer, the PGR modifies the way grass grows and the way plants develop. The PGR slows the plant from continuing to elongate (i.e., growing taller) by forcing the plant to redirect its energy to developing root systems and continuing to maintain turf density. As a consequence, the grass that results from this process is healthier, has greater resiliency, and will require less frequent mowing while maintaining a uniform appearance over time.

Why PGR for Grass Matters in Turfgrass Management

In large turf areas that are high maintenance and require consistent growth and durability of the grass (turf), the use of Plant Growth Regulators (PGRs) is extremely important.

PGRs provide several important benefits for grass including:

• Less frequent mowing.
• Deeper & stronger root systems.
• Improved turf Color and density.
• Improved heat / drought tolerance.
• Long-term soil health support.

Turf systems that utilize PGRs enable turf managers to have controlled and steady growth patterns that result in a better-quality grade turf, without having to increase their labour and/or resources. Sports fields, golf courses, recreational parks and pastures are examples of large grassy areas that are ideal for the application of PGRs.

Types of PGR Fertilizer Used for Grass 

A fertilizer that is a combination of nutrients & regulatory action is a complete solution to turf management. The use of a PGR fertilizer provides all necessary nutrients and PGR benefits in one application.

Typical types of PGR Fertilizers Include:

• Nitrogen Fertilizers with Growth Suppressants
• Root-Enhancement PGR Blends
• Stress Relief PGR Formulations
• Slow Bulk Fertilizers with Regulatory Actions

How PGR Fertilizer Works on Grass Growth

In modern turf management practices, PGR fertilizers help to keep grass growing while controlling the excessive vertical growth, ultimately resulting in healthier grasses. Plant growth regulators (PGRs) do not force the grass to produce vertical shoot (leaf) growth, but rather the PGRs help grass to redirect energy away from vertical growth and into developing deep roots, creating thick, dense turf with stable colour. 

When applying PGRs to lawns or athletic fields, PGRs help to create more uniform, stress-resistant, and easy-to-maintain lawns and athletic fields. Properly applied, PGRs will promote the development of consistent growth, thereby eliminating the need to mow frequently, save fertilizer, reduce nutrient loss, and maintain healthy, green turf.

The Science Behind Plant Growth Regulators

PGRs influence the natural hormones within grass, which control the growth and development of grass.

Mechanisms of Plant Growth Regulators:

• Slow excessive vertical leaf growth
• Regulatory hormones such as gibberellins
• Increasing water and nutrient efficiency
• Reducing stress from mowing and/or heat

As with a baby, rapid, shock-like growth stimulates healthy digestion through reduced stimulation. Similarly, PGRs limit rapid shoot elongation and conserve energy by providing balanced development for grass plants that promotes a robust turf grass with continuous green colour and resistance to stress.

Impact of PGR for Grass on Root Development

The main advantage of using a PGR application on grasses is the enhancement of a grass's root system. Benefits of PGR's effect on root growth are:

• Increased depth and strength of roots
• Increased drought tolerance
• Increased absorption of nutrients
• Decreased amount of surface stress damage

When the grass does not have to put as much energy into upward growth, it directs more energy into developing its root system below ground. When applying PGR fertilizers, it develops stronger roots, allowing the grass to penetrate deeper for moisture and nutrients. Thus, the grass is able to recover much more quickly from heat, foot traffic, and water stress than non-PGR-treated turf and is highly desirable for use in lawns, golf courses, and athletic fields.

How PGRs Improve Turf Density and Color

By using PGR's to help the grass thicken up, and the retention of a consistent green color throughout the growing season.

Improvements in turf quality include:

• Increased Tillering/Shoot growth
• Increased density of the grass; carpet-like appearance of turf
• Retained chlorophyll content
• Retained green color for longer periods of time

The application of the PGRs, which help promote lateral shoot growth instead of excessive vertical growth, creates a thicker area of turf. A thicker area of turf will block sunlight from hitting the underlying soil and suppress weeds. A balanced application of PGR fertilizer will assist in retaining the richer green color for extended periods, even with reduced amounts of nitrogen applied.

Benefits of Using PGR for Grass in Agriculture

The advancements in PGR offer many benefits for grass-based agriculture, especially when used in combination with proper, balanced fertilizer applications (as in the above graphic). PGR's ability to control higher than normal vertical growth rates increases the durability and uniformity of PGR-treated grasses, while at the same time improving the turf cover of the grass through denser, stronger root systems.

Reduced Mowing and Labor Costs

The most obvious effect of using PGR is the reduction of vertical growth, which decreases the frequency of mowing required for turf maintenance, resulting in reduced labor costs, equipment wear, and fuel consumption. Benefits of PGR include:

• Reduced Vertical Growth Rate
• Reduced Mowing Frequency
• Reduced Labor Costs
• Reduced Fuel Usage
• Reduced Wear on Equipment
• Uniform Height of Turf

Much like PGR-treated grasses are easier to digest (compared to unregulator-treated grasses), they also provide better control over how they grow, allowing for greener, thicker grasses that do not have excessive vertical growth rates. The regulation of shoot elongation achieved through the use of PGR allows grasses to remain healthier longer by allowing for more uniform growth patterns, reducing the need to mow that grass. Therefore, using PGR on grass will save both time and money in managing large agricultural and landscaping areas.

Improved Drought and Heat Resistance

Plant Growth Regulators Improve Adaptability of Grass to Environmental Stress such as High Heat and Low Water Availability.

How Plant Growth Regulators Improve Grass's Resistance to Environmental Stress:

• Increased Depth of Root Development
• Increased Water-Use Efficiency
• Reduced Heat Stress
• Ability to Maintain Turf Color During Dry Conditions

Fast-growing grass may only have a small amount of root development due to the fact that it is focused on top-growth. A plant growth regulator re-directs that excess energy from the top-growth to the root development. The result is a stronger root system which absorbs water more efficiently. When combined with a balanced PGR fertilizer, grass treated with a PGR is better able to withstand high heat and drought stress. This makes PGR-treated grass well suited for sustainable agriculture and for water-efficient/management.

Long-Term Soil and Turf Health

In addition to improved visual appearance of turf, PGRs also help develop a healthier soil system through the use of PGRs over time.

The long-term benefits of PGRs are:

• Reduced build-up of thatch,
• Improved microbial activity in the soil, 
• Enhanced uptake of nutrients by the turf, 
• Improved density and coverage of the turf.

Healthy turf results from healthy soil. The use of plant growth regulators reduces top growth on the grass to improve efficiency of nutrients within the plant, promote balance in the biology of the soil, and reduce nutrient runoff. Over time, turf growing using plant growth regulators develops stronger crowns with greater density and resistance to weeds, thus improving the health of the soil and turf overall.

How to Apply PGR Fertilizer to Grass Correctly

Correctly applying a PGR fertilizer requires proper timing, usage techniques, and application dosages to obtain strong, healthy, thick and uniform turf grass. Grass responds best to PGRs when applied during the proper growth phases (i.e. Seasonally). Turf growth is slowed by applying the correct amounts of PGRs, which allows for improved root growth, color, and reduced mowing frequency, thus improving maintenance of Agricultural, Sports, and Landscaped Areas. 

Best Time to Apply PGR for Grass

• Time is Essential for Grass to Use PGR Fertilizer Correctly.
• Grass should be actively growing during Spring and Early Summer months.
• When Grass is Healthy and Free from Drought Stress.
• When Grass is Preparing for Periods of High Vertical Growth.
• When Grass has Sufficient Leaf Area after Mowing. 

Importance of Timing: The more progressive and timely you apply PGRs, the better it will benefit the Grass by Eliminating Energy from Excessive Shoot Proliferation and Redistributing Energy from Excessive Shoot Proliferation to Root Development and Lateral Proliferation of the Grass Root System. Applying PGRs at the Right Times Provides Uniform Distribution of Turf Density and Prevents Stressing of Turf, while Too Late and/or Poorly Timed Applications Will Not Yield the Full Benefits of PGRs.

Application Methods in Agricultural Lawns

Application techniques differ based on the type of turf, the size of the area, and the type of equipment available.

A few Common Application Techniques include:

• Foliar Application via Boom or Hand Sprayer
• Granular Application with Irrigation
• Liquid Application in conjunction with Nutrient Program

The preferred method for applying product (n) to a large area of turf or agricultural lawn (turf) is to utilize the Foliar Application method, since it provides better overall coverage and allows for faster absorption of the product(s) into the blades of grass. Additionally, Granular pgr fertilizers should be incorporated into a regular schedule of turf/grass fertilization and followed up with a light irrigation to activate the product; this provides an effective way to apply Granular product.

Dosage and Safety Guidelines

Proper application of the appropriate amount of plant Growth Regulator (Pgr) is critical to minimize turf stress and uneven turf growth, as follows:

Pgr Dosage Practices:

• Follow label recommendations for the manufacturer strictly.
• Modify Pgr dosage according to the grass species and growth stage of the grass.
• Avoid spraying over the same area where the last application was made.

Do not apply Pgr when temperatures are excessively high and/or the turf is experiencing a severe drought.

Safety Procedures:

• Use gloves and a mask during application.
• Avoid entry by people and pets to the treated area until the spray has completely dried.
• Thoroughly clean the sprayer after each use
• Store Pgrs in a cool dry location.

The effects of Pgrs on Grass are accomplished by regulating the internal hormone activity of a plant and do not induce growth artificially. Excessive use of Pgrs may temporarily discolour the grass and/or suppress the growth of the grass. Proper use of Pgrs will improve the quality of the Turf and reduce maintenance (mowing) on the turf; Therefore, turf treated with Pgrs has a better long-term health and does not harm soil or adjacent vegetation.

Choosing the Right Plant Growth Regulators for Grass

The importance of selecting the appropriate plant growth regulators (PGR's) for different types of grass is critical in providing a well-maintained, lush, and aesthetically pleasing lawn. 

Similar to how different types of millets are best utilized at various points throughout your child's growth, the selection of different PGR's will depend upon your turf grass type, the growing environment, and your management goals. 

When PGR's are utilized correctly, they will aid in controlling excessive leaf growth, developing a deeper root system, providing greater colour consistency, and minimizing maintenance.

PGR Selection Based on Grass Type

It is important to recognise that the multitude of different grass varieties each respond to PGR's differently; therefore, when you are selecting your PGR, you must match the PGR to the type of grass that you are growing.

The following key points should be kept in mind depending on the grass type that is being grown:

• For Cool-Season Grasses (Bermuda & Fescue), PGR's that suppress shoot growth will work best.
• For Warm-Season Grasses (Zoysia & Ryegrass), Root-promoting or growth-stimulating PGR's will be most beneficial.
• For Sports Turf, PGR's should be selected that promote stress resistance and, consequently, assist in rapid recovery after stress.

Typical Home Lawns should use PGR's that are moderately productive and relatively safe for residential use. Many times, PGR's selected for home lawns will be slower-acting and less aggressive but still serve the purpose of enhancing the density and colour of the lawn.

Professional vs Home-Use PGR Products

PGRs are not created equal in terms of how and where to use them. A complete understanding of the distinctions will help eliminate mistakes by improperly applying PGRs, thereby preventing damage to turfgrasses.

PGRs formulated for Professional Use:

• A higher concentration formulation of the respective PGR product
• Used on golf courses and sports stadiums and Commercially maintained Lawns
• Require that the applicators of the product have received adequate training and can provide the proper amount of the PGR in terms of dosage.
• A longer duration of regulation of turf growth.

PGRs formulated for the Home-Use category: 

• A lower concentration formulation of the respective PGR product and therefore safer to handle than a professional-use PGR
• A simple way to apply the PGR using most standard spray equipment
•  Formulated for home lawns, residential and home garden turfgrass.
• Less chance of excessive application.

In the same way that specialised baby formula is cared for with caution, Professional PGRs require expert precision when applying them to turfgrass. When applying PGRs to your lawn or garden, it is important to use the right category, as this will ensure that the benefits derived from the PGR will be provided to your turfgrass without causing turf quality or safety issues.

Compatibility with Fertilizers and Inputs

Combining PGRs with proper fertilizer, micronutrients, and soil conditioners produces the best results.

Compatibility tips:

• Combine PGRs with balanced fertilisers containing PGRs for consistent growth.
• Do not combine PGRs with High Nitrogen fertilisers during the application of the PGR.
• Soil conditioners should be used to aid in root support in conjunction with PGRs.
• Always conduct a jar test before identifying any incompatible products and mixing them.

FAQs : 

Q1. Is PGR for grass safe for agricultural lawns?

Yes, PGR for grass is safe when applied at recommended rates and is widely used on lawns, farms, and managed turf areas.

Q2. Does PGR fertilizer replace regular fertilizer?

No, a PGR fertilizer complements regular fertilizers by controlling growth and improving nutrient use, not replacing basic nutrition.

Q3. How long does PGR for grass last?

Most PGR treatments last between 3 to 6 weeks, depending on grass type, weather, and application rate.

Q4. Can plant growth regulators damage grass?

Plant growth regulators are safe when used correctly, but overuse or incorrect timing can temporarily stress grass.

Q5. Is PGR suitable for sports fields and commercial turf?

Yes, PGRs are commonly used on sports fields and commercial turf to improve durability, uniformity, and maintenance efficiency.

Conclusion: Why PGR for Grass Is Essential for Sustainable Turf

Plant growth regulators (PGRs) are a viable and sustainable option for modern turf management. The use of PGRs allows for the management of excessive top growth while enabling more vigorous root growth, greater colour consistency, and a greater ability to withstand stress. Healthier turf will be able to be mowed less often, use water more efficiently, and absorb more nutrients, which are important components of maintaining sustainably-managed agricultural, sports and commercial landscapes.

PGRs, when used in conjunction with the proper PGR fertilizers and good turf care practices, provide a durable and sustainable turf solution that does not negatively affect either the soil or the environment. 

These products will reduce maintenance costs, prolong the durability of turf, and help develop grasses that have the ability to resist heat, drought, and high traffic. Thus, for anyone looking to create resilient, low-maintenance, and eco-friendly turf, PGRs are no longer an option but rather an integral component of sustainable grass management.