Pesticide use in ornamental nurseries: A new tool from IQDHO helps growers to make an informed choice

By: Annie Christine Boucher, M. Sc., Project manager, IQDHO

The Quebec Institute for the Development of Ornamental Horticulture “Institut québécois du développement de l’horticulture ornementale (IQDHO)” has recently developed a tool to support nursery and garden growers, horticulturists in municipal green spaces, and ornamental horticulture advisers in their choice of phytosanitary treatments. Available free of charge on the Agri-Réseau website, the “Pesticides approved in ornamental nurseries” poster collects information on plant protection products in nurseries (perennials, shrubs, and ornamental trees). It presents a wealth of useful information on each product (active ingredient, health risk index, environmental risk index, re-entry time, etc.), their effectiveness on the various crop pests, and their impacts on auxiliary fauna.

A need of the sector

This tool fills a need for centralized information for the choice of pesticides to promote the use of integrated pest management for the control of diseases and pests in ornamental nurseries. Indeed, relevant information on the subject exists but is fragmented into different sources. In addition, advisers and stakeholders in ornamental nurseries have noted the effectiveness of the various products used in Quebec for several years. Thus, the data presented comes from an exhaustive literature review of current knowledge in the field.

Effectiveness on crop pests and toxicity on beneficial organisms

The poster designed by IQDHO is intended to be a simple and effective tool that collects information about the effect of commonly used products on the commonly grown plant species of Quebec nurseries while ensuring their effectiveness for the targeted problems (diseases and pests). This information is presented in the sheet using an effectiveness rating (numerical scale from 0 to 3) and a toxicity rating (no or little toxic, moderately toxic, and high toxicity). A total of 39 insecticides, 29 fungicides, and beneficial nematodes are presented. Twelve major pests, as well as 11 diseases of interest, were selected. A selection of seven beneficial insects was made from among pollinators, predators, and parasitoids. Thus, the poster will allow stakeholders in the field to ensure the effectiveness of the product chosen while considering the sensitivity of beneficial insects such as pollinators, predators, and parasitoids. Adopting such phytosanitary practices could thus help reduce the number of pesticide applications required, help maintain populations of beneficial organisms, and potentially lower production costs.

The poster was created by IQDHO in collaboration with the ornamental nursery RAP under part 4 of the 2013-2018 Prime-Vert program and received financial assistance from the Ministry of Agriculture, Fisheries and the ” Food (MAPAQ) through the Quebec Phytosanitary Strategy in Agriculture 2011-2021.

For more information on this subject, we invite you to contact Annie Christine Boucher, M. Sc., Project Manager, IQDHO (