Profile 2SC - Tree Growth Regulator

Science of Profile 2SC

Profile 2SC tree growth regulator (TGR) is a xylem mobile plant growth regulator that slows vegetative growth by inhibiting gibberelin biosynthesis. Profile 2SC reduces shoot growth thereby reducing the volume of biomass that must be removed from trees when trimming occurs and may extend the trimming cycle. Profile 2SC also may serve as an effective preventive action or rehabilitative treatment for trees growing in stressful conditions.

Much of the energy of a tree is directed into growth, and the rate of growth is directly related to the rate of energy use. Fast growing trees tend to have shorter lives than trees that grow slowly and can allocate more energy away from the canopy.

Gibberelic Acid

The active ingredient in Profile 2SC, paclobutrazol, inhibits the biosynthesis of gibberellic acid - the compound responsible for plant cell elongation. As gibberellic acid production decreases, production of other compounds like abscisic acid and chlorophyll increases.

Abscisic Acid

Both abscisic acid and gibberellic acid are produced from the same starting material, thus when gibberellic acid formation is decreased, abscisic acid production increases. Abscisic acid induces responses that protect the tree and help plants withstand and respond to environmental stresses. The effects of increased abscisic acid include stimulation of stomatal guard cell closure and an increase in the defense response of the tree.

The closure of stomata limits water loss from transpiration, maintaining leaf water relations and lowering the risk of scorch and tattering caused by severe leaf dehydration. In addition, the amount of carbon dioxide that enters the leaf is reduced, limiting photosynthetic capacity during optimal conditions. When conditions become stressful, the benefit of improved water relations allows photosynthesis and other metabolic functions to proceed in treated plants while untreated plants shut down.

Chlorophyll

Chlorophyll molecules are made up of a ring structure with a magnesium atom at the centerending in phytol. When gibberellic acid formation is inhibited, more phytol can be formed and chlorophyll levels can be enhanced, resulting in a darker green leaf.

Carbohydrates produced by photosynthesis support all metabolic processes of life, and allocation of this limited resource is very important. Energy not spent on above ground vegetative growth is allocated to a tree's root system , defensive chemical production and storage for future needs.

The Effects of Profile 2SC

Reduced vegetative growth for less pruning
First and foremost, you'll spend a lot less time and money on pruning. After one treatment with Profile 2SC , vegetative growth is generally reduced by 40-60% over a three-year period, depending on the species. The reduction of growth allows you to extend pruning cycles, maintain your pruning work longer and preserve trees growing in restricted spaces.

Root system enhancement in some species
The action of Profile 2SC allows carbohydrates that would be used for vegetative growth to be re-allocated to the stimulation of a fibrous root system in oak, elm, and maple trees. This increase in fine root density can be beneficial to trees in mild decline, perhaps in construction areas or any situation where an enhanced root system is desirable.

Higher root-to-shoot ratio
Profile 2SC provides a reduction of vegetative growth as well as a stimulation of the root system in some trees. This creates a higher ratio between the roots and canopy, or branches, of the tree, reducing the chance for imbalances in a treated tree's supply of water and minerals. This can benefit trees in both dry locations and environments where the available root area is limited such as in parking lots, planters, sidewalks and urban yards.

Potential for some disease suppression
Leaves of trees treated with Profile 2SC tend to be slightly thicker than those of untreated trees, their stomatal guard cells will be closed more often and they tend to have thicker cuticles with more leaf hairs, or trichomes. These attributes can possibly make a tree treated with Profile 2SC less vulnerable to disease.

Potential improved resistance to drought, pollution and temperature extremes,
The re-allocation of resources to defense and storage may allow trees treated with Profile 2SC to better handle stressful conditions like drought, heat and pollution. The benefit of improved resource relations may allow photosynthesis and other metabolic functions to proceed in treated trees while untreated trees might shut down.