City Trees is a premier publication focused on urban + community forestry. In each issue, you’ll learn how to best manage the trees in your community and more!
Issue link: http://read.dmtmag.com/i/30662
field tool that can be utilized by many stakeholders to accomplish multiple objectives. Tree growth regulator (TGR) technology has been around for over half a century. During that time, paclobutrazol has emerged as the most effective and predictable active ingredient. Paclobutrazol is used widely in both utility and commercial arboriculture. The product is applied to the soil around the base of a tree and trans- ported to the growing points of the tree during transpira- tion. It works by reacting in the subapical meristems of the plant to inhibit the production of gibberellins which are responsible for cell elongation. The plant still has the same amount of energy available but is utilizing less energy for growth. Since less energy is allocated to growth, the plant has more energy available for reproductive structures, fine root development, storage compounds, and increased defense compounds. This change in growth leads to increased chlorophyll, thicker leaves, more abscisic acid, and a plant more suitable to the hostile conditions of the urban forest. Utility arborists use paclobutrazol to reduce the amount of growth in trees near power lines. This helps reduce costs, enhance customer relations, maintain cycles, and deliver safe, reliable power. Commercial arborists utilize growth regulators to improve the health of trees, reduce maintenance costs, and improve the ability of the tree to handle urban stress. Kevin Scott with American Electric Power (AEP) uses TGRs to build partnerships with many of the munici- pal arborists inside of his territory. In Fort Wayne, Indiana he works closely with City Manager of Forestry Operations Chad Tinkel. Kevin and Chad work together to determine which city trees can be removed and which trees need to be pruned. A few years ago there were a number of city trees along a boulevard that Kevin really wanted to remove to ensure safe and reliable power. Chad said that the trees could not be removed in this situation because they were critical to the overall land- scape of the neighborhood. Kevin and Chad came to the agreement that AEP would treat the trees with TGRs and the City would prune the trees using their crews. The TGRs would slow the growth of the trees and allow for less frequent pruning. The City pruned the trees so they could prune the whole tree and not just the portion which had limbs growing near the power lines. This was a good way to cost-share and come to an agreement that would satisfy both stakeholder’s objectives. Another way Kevin utilizes this tool is to improve public relations. Kevin attends City neighborhood meetings to discuss the benefits of TGRs before applications are made. This gives the residents an opportunity to see that the utility is using multiple tools to minimize the impacts on the citizens. It is also a great opportunity www.urban-forestry.com A utility arborist applies paclobutrazol to reduce the amount of growth in trees near power lines. for the utility to meet with the homeowners in an open environment and share information about TGRs. The better the communication and more informed the hom- eowners, the more open and accepting they become to the objectives of the utility. Kevin conveys that utilizing TGRs results in sustained clearances which leads to longer pruning cycles and less impact on property. TGR benefits also include cost savings and the reduc- tion of pruning for the next cycle. Grant Ehlen is the forestry operations supervisor for AEP in Texas. Grant decided to look at the benefits of TGRs on an entire circuit in need of pruning; the crew pruned and treated 1,300 trees. When he returned to the circuit after three growing seasons, he found that only 200 of the 1,300 trees needed to be pruned, resulting in a 60% cost reduction. TGRs have the unique ability to reduce the growth while improving the health of a tree. This unique ability allows this tool to meet the objectives of multiple stakehold- ers. By integrating TGRs into a vegetation management plan, we can build a working relationship between municipal and utility arborists. Developing partnerships is a great way to enhance the urban forest, deliver safe reliable power, and eliminate the perception that utility arborists are “tree butchers”! 17