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Icon ShortStop® Tree Growth Regulator

ShortStop® Tree Growth Regulator is used by Arborists and Landscape Professionals to slow the annual growth of trees and woody shrubs while maximizing the other benefits that accompany the TGR results. The active ingredient in ShortStop TGR is paclobutrazol (22.3%) and is sold in half gallon and gallon containers (approx 2 and 4 liters). ShortStop TGR is competitively priced and PGMS provides support that surpasses all others, from refined arborist rates to extensive background in remedial TGR treatments.


THE BASICS, THE BIOLOGY, AND THE BUSINESS SOLUTIONS

The Basics of how it works:
Shortstop Tree Growth RegulatorShortStop Tree Growth Regulator slows the annual growth of trees and woody shrubs and indirectly creates additional benefits that help trees and woody shrubs withstand urban stress, such as poor soil, limited root space, & drought conditions (Watson 1996, Chaney 2005). The recommended application is sub-soil; either basal drench or soil injection. Growth control on trees varies between 2-4 years and on woody shrubs is about 2 years, depending on average length of growing seasons. For details about application steps or to see a map of length of control, click here.

To determine the volume needed for trees, the species is identified and the diameter at breast height (dbh) is measured. Tree species fall into twelve (12) rate categories and using the dbh of the trunk, the volume can be easily found on our slide chart. Click here to see or order our TGR Rate Slide chart.

NOTE: For over 20 years, Plant Growth Management Systems has refined the tree rates and application process for tree growth regulators. The improved rates, the crown size recommendations, and the differentiation between arborist & utility rates have prevented over-regulation of TGRs for the companies who have utilized them.

The Biology of ShortStop TGR: 
The active ingredient in ShortStop Tree Growth Regulator is paclobutrazol (22.3%). If the application is done during the time the tree is transpiring, the product moves up the tree and collects within the growing points of the branch, the sub-apical meristem. The product takes 20-35 days to move from the roots to the crown. If the application is done in late fall or winter, the product will stay in place until transpiration begins in the spring. Paclobutrazol will not move from the application site because it is water insoluble, thus can be applied at any time of the year (except when soils are frozen or super-saturated).


Once the paclobutrazol reaches the sub-apical meristems, it interferes with the production of gibberellic acid, causing a reduction in the elongation of the cells located there (Chaney 2005). The result is seen as shorter length between internodes on the branch. The overall growth control is 85-95%, except during the first year of application in which growth control is more likely to be 55-70%.

Because energy is reserved due to less cellular elongation, energy is redistributed from the crown to other parts of the tree, including the production of roots hairs and starch reserves. The reduced production of gibberellic acid indirectly manufactures more abscissic acid which helps the tree respond to stressful situations. Other changes occur following a TGR application that benefit trees and woody shrubs in difficult urban environments: smaller stomata, increased leaf hairs, thicker cutin, more chlorophyll production, and enhanced pest resistance. It is these benefits, along with the growth control, that provide a vast array of solutions for Arborists and Landscape Professionals to use with their client services.

The Benefits transformed into Business Solutions:
Tree growth regulatorAn application of ShortStop Tree Growth Regulator produces beneficial changes that help with urban stresses in trees and woody shrubs. It can supply a solution to many dilemmas that may arise from your client’s landscape, such as trees damaged from construction or growing close to a picture window, a poolside or an electric line. Specific physiological changes in the leaf after a TGR application, such as smaller stomata, increased leaf hairs, and thicker cutin, can help clients’ trees grow in areas where drought is a common occurrence. Stress on trees growing in poor soil or limited space can be greatly alleviated after a TGR application because the ShortStop enhances root hair growth. For more thorough examples of transforming the benefits that trees or woody shrubs receive from using ShortStop TGR into business solutions see the chart below.


REFERENCES:
Chaney, W.R. 2005 Growth Retardants: A Promising Tool for Managing Urban Trees, FNR-252-W Purdue Extension Publications.
Watson, G., 1996. Tree Root System Enhancement with Paclobutrazol, JOA, 22(5):211-217.


Business Solutions; Creative Uses of TGRs to add to your Arborist Toolbox

Physical Enhancement: Energy is redistributed

Resulting Advantage

Profitable Treatment

Root hair growth increases

Better root system creates healthier trees & shrubs

Increased carbohydrate storage

Trees & shrubs thrive within urban stress

Root hair growth increases

Reduces the impact of construction damaged

Root hair growth increases

Enhances survivability during transplant phase

Root hair growth increases

Aids in poor soil or limited growing space

Root hair growth increases

Long term solution for chlorosis in trees

Root hair growth increases

Decline is diminished in mature Oaks

Root hair growth increases

Assists in establishing newly planted trees

Increased carbohydrate storage

Assists in establishing newly planted trees

Physical Enhancement: Thicker cuticle on leaf

Resulting Advantage

Profitable Treatment

Reduces water vapor loss

Helps trees & shrubs resist drought conditions

Changes the leaf physiology

Increased pest resistance

Physical Enhancement: Smaller stomata size

Resulting Advantage

Profitable Treatment

Changes the leaf physiology

Increased pest resistance

Reduces water vapor loss

Reduces impact of drought & urban stress

Physical Enhancement: Enhanced root hair growth

Resulting Advantage

Profitable Treatment

Holds more water in soil

Reduces impact of drought & urban stress

Utilizes available minerals

Allows for more effective soil enhancements

Physical Enhancement: Increased leaf hairs

Resulting Advantage

Profitable Treatment

Reduces water vapor loss

Aids landscape plants in drought-like conditions

Changes the leaf physiology

Increased pest resistance

Physical Enhancement: Reduction of gibberellic acid production

Resulting Advantage

Profitable Treatment

Shorter length between internodes of branch

Slows the growth of crowded landscape

Shorter length between internodes of branch

Good alternative for utility electric trimming

Less elongation of cells in sub-apical meristem

Control the growth of woody shrubs & hedges

Less elongation of cells in sub-apical meristem

Prevent trees from shading pools, decks & patios

80-95% less annual branch growth

Hinder overgrowth on golf courses and at resorts

Physical Enhancement: Increased production of abscissic acid

Resulting Advantage

Profitable Treatment

Helps trees in stressful circumstances

Decline is diminished in mature Oaks

Helps trees in stressful circumstances

Reduces the impact of construction damage

Physical Enhancement: More chlorophyll created

Resulting Advantage

Profitable Treatment

More green, healthy leaves

Long term solution for chlorosis in trees

Ability to produce more carbohydrates

Help with decline in trees