Impact of composite hedges on natural enemies and pollinators in an organic polyculture system in Québec

Description

This two-year project was conducted on an organic polyculture farm in southern Québec (Ferme des Quatre-Temps).

The first stage of the project focused on describing the polyculture system and how the hedges are planted and maintained. Interactions between the polyculture and the hedges were studied, based on the insects associated with crops in the cabbage family. Insects were sampled on plots to check for parasitism of immature pest stages (caterpillers and pupa) on the crops and in adjacent hedges to determine what natural enemies and pollinators use them as a refuge. This data was used to identify the plant species most used by natural enemies and pollinators. The project also looked at the economic aspects of planting recommended species and the economic benefits of various control strategies for Lepidopteran pests of the cabbage family.

Objective(s)

• Get a better understanding of interactions between a vegetable polyculture system and hedges composed of shrubs and perennials in order to enhance the impact of beneficial insects on vegetable crops in Québec
• Analyze the cost of planting and maintaining the hedges and conduct a comparative cost study of various pest control strategies
• Produce a technical leaflet on how to conserve and increase biodiversity in farming areas, especially for the growing number of organic vegetable farms