By Ty McDonald
University of Hawaii at Manoa College of Tropical Agriculture and Human Resources Cooperative Extension Service
For the most part, stronger and more toxic pesticides are allowed on ornamental plants, compared to food crops, simply because people usually don’t eat their landscape.
In recent years, however, an increased interest in edible landscaping has accompanied a similar increase in home vegetable gardening nationwide. Many people are incorporating edible landscape design elements to their properties such as fruit trees, especially dwarf trees for small residential properties, herbs in flower beds and edible hedges.
As yards get smaller, and food plants intermingle more and more with ornamental plants, or even replace ornamental species, there is more interest in reducing or eliminating the use of those stronger, broad spectrum pesticides. This situation increases management challenges for landscape gardeners trying to strike a balance between effective pest control and sustainable, environmentally-friendly practices.
In recent years, agricultural systems have focused on integrated pest management programs and alternative methods of pest control to reduce pesticide use due to food safety issues, groundwater contamination, and increased environmental awareness.
Environmental Impact Quotient
Formerly, pesticide selection was often based only on efficacy or cost. In response, Cornell University developed a user-friendly system for selecting agricultural pesticides based on their potential environmental impact.
Because of the Environmental Protection Agency pesticide registration process, an abundance of toxicological and environmental impact data exists for most pesticides commonly used in agricultural systems. However, this information is not readily available or organized in a manner that is usable to the typical applicator.
To address this problem, the folks at Cornell developed a model to organize and simplify the extensive data: the environmental impact quotient of pesticides. This model reduces the environmental impact information to a single value. To accomplish this, an equation was developed based on the three principal components of agricultural production systems: a farm worker component, a consumer component and an ecological component.
Basically, it works like this. The lower the EIQ number of a pesticide, the lower the potential environmental impact. By using the EIQ rating, pesticide applicators, IPM practitioners, and home gardeners can include environmental effects in addition to efficacy and cost into the pesticide selection process.
These timely issues of sustainability in landscape design and maintenance (including edible landscapes and EIQ) are the theme of the upcoming fourth annual Hawaii Island Landscape Management Conference and Trade Show. The conference, presented by the Hawaii Island Landscape Association and the University of Hawaii Cooperative Extension Service, is slated for Saturday, Nov. 23, at the Hapuna Beach Prince Hotel.
The event focuses on providing practical management tools for professional landscape gardeners and tree workers. It is also open to property managers and the public. Two tracks of concurrent educational sessions are offered in tree care and landscape plant management. The program features local experts from the green industry and the University of Hawaii.
Kicking off the conference are plenary speakers Craig Elevitch and Andrea Dean, co-directors of Ho‘oula ka ‘Ulu — Revitalizing Breadfruit. They will discuss “Hawaiian Agroforestry Landscapes: reconnecting people to a sustainable landscape.”
You can learn more about the use of EIQ in landscape applications from Kona horticulturist Chris McCullough. Chris adapted the agricultural-based system described earlier while developing an IPM program that uses low EIQ pesticides that actually work on landscape pests.
Landscape architect David Tamura will touch on edible landscaping while discussing the harvest garden. Jamie Nahl, from Plant It Hawaii, will talk about suitable fruit trees for Hawaii landscapes.
Learn the latest green technology from Dr. Andy Kaufman of the University of Hawaii, who will provide an update on the latest green roof and green wall applications in Hawaii. Dr. Zhiqiang Chen, also of UH, will describe sustainable turfgrass management practices for Hawaii lawns.
For palm enthusiasts, Garrett Webb, a consulting arborist and palm nurseryman, will discuss two case studies presented by tsunami and rising sea levels. Butch Porter, Kona Coqui Specialists, will share his knowledge and experience gained from over a decade of hunting the tiny, but mighty coqui frog. Yes, some neighborhoods are still coqui-free.
And last, but certainly not least, we cannot talk about sustainable landscapes in Hawaii without including native plants. Heidi Bornhorst, native plant expert and author, will talk about alternative native Hawaiian plants and techniques to perpetuate natives.
Recertification credits (CEU) are available for Landscape Industry Certified Technicians (formerly CLT), licensed pesticide applicators (HDOA) and certified arborists (ISA).
Cost for the conference is $90 for HILA members and $110 for nonmembers if registration is postmarked by Nov. 5. The event runs from 8 a.m. to 4 p.m. Lunch is provided.
Some of the information for this article came from www.nysipm.cornell.edu/publications/eiq.