Collaborative Study of Trimtect®️ as a Plant Growth Regulator on Shrub Physiology and Drought Tolerance

Abstract

Paclobutrazol is a synthetic plant growth regulator known to reduce the size of plants and improve drought tolerance in some species. Paclobutrazol blocks a key step in the formation of gibberellic acid (GA), a plant hormone that stimulates growth and development, therefore resulting in modified growth. Trimtect, a product made by Rainbow Treecare Scientific Advancements (Minneapolis, MN), incorporates paclobutrazol and is being formulated for commercial use, as some of the associated changes in growth are desirable from a landscaping maintenance point of view. However, a better understanding and record of physiological responses to Trimtect treatments are needed. Therefore, to better understand plant growth regulation, we partnered with Rainbow Treecare Scientific Advancements to study the effects of their current Trimtect formulation on the physiology of three common shrub species undergoing water stress. The information from this study is helping Rainbow Treecare Scientific Advancements refine formulations to improve their product for use in low maintenance landscapes.