Arboriculture & Urban Forestry

Volunteerism is one way to handle limited resources for municipal inventories. This study follows the Forest Health Ambassador Program and how it used volunteers to track signs and symptoms of infestations by emerald ash borer, gypsy moth, and Asian longhorned beetle. (A,M,Bs)

Apple and pear scab caused by the fungal pathogens Venturia inaequalis and V. pirina can be devastating to apples (Malus spp.) and pears (Pyrus spp). This article details two UK field trials that assessed the efficacy of alternatives to the synthetic fungicides frequently used in fruit production, including a range of silicon fertilizers, a resistance-inducing (IR) agent, and a combination of Si + IR. (A,Bs)

While the industry-standard black plastic container has many advantages in woody plant production, circling and girdling roots on plants grown in them can lead to a variety of post-transplant problems. Plants grown in fabric containers may have fewer circling and girdling roots, potentially eliminating some transplant problems. This study evaluated post-transplant root and shoot growth of Pyrus calleryana ‘Glen’s Form’ (Chanticleer®) produced using three container types. (A,Bs)

It is challenging to successfully grow trees in highly-urbanized areas, such as downtown commercial-retail districts. This research reports on an investigation of multiple abiotic factors that may have contributed to the decline and mortality of 133 London planetrees that were planted in downtown Toronto, Ontario, Canada as part of a streetscape revitalization project. (A,M,Bs)

The costs of collecting data necessary for urban forest management can be prohibitive for communities with inadequate financial or staffing resources. In this study, researchers assessed volunteer efficacy and the effect of training protocols on data quality by comparing volunteer-collected and university-collected tree inventory data in nine Minnesota, U.S. communities. (A,M,Bm)

Integrated vegetation management programs have successfully reduced the frequency and intensity of power line right-of-way management by promoting low-growing plant communities resistant to tree invasion. To examine whether these principles are transferable to northern ecosystems, researchers tested different methods of imazapyr and triclopyr treatments in Yukon, Canada (A,U,Bs).

Chlorantraniliprole has become a mainstay for managing turfgrass pests, but little has been published concerning its performance against the pests of woody ornamentals. In this article, researchers evaluated the use of chlorantraniliprole against pests spanning five different orders using real-world scenarios. (A,M,Bs)

Cottonwood trees are a staple of semi-arid environments, but there’s a fine line between the minimum amount of water needed to maintain health, and mortality. The results from an 11-year study look at year-to-year growth, and die-back, patterns. (A,Bs)

Trees play an important role in improving environmental quality, but they can also act as living indicators for the state of the urban environment and help mitigate dangerous pollutants such as heavy metals. This study focused on nine species of ornamentals commonly placed along urban streets in Central Europe. (A,M,Bs)

The methods for appraising urban trees and municipal inventories in use today are expensive and time consuming. Researchers present a statistical methodology to analyze tree size variables applied in appraising urban trees. (A,M,Bm)

How far a limb flexes with or without leaves can be of great concern when those limbs overhang powerlines. Does an early snow or ice storm pose a more serious threat if it hits before a tree drops its leaves and enters its dormant stage? Gregory Dahle, Aaron Carpenter, David DeVallance, and Mo Zhou investigate. (A,U,Bs)

Tree fertilization is a common practice in arboriculture, and while reports have shown that nitrogen can increase fine root growth in localized areas, the effect on a tree’s entire root system has not been thoroughly investigated. Gary Watson and Angela Hewitt take a look at how effective fertilizer can be as a root stimulant. (A,M,Bs)