Activity 19

Saponins as inducers of host resistance for insect and disease management in organic greenhouse production


Project Introduction

Pest control treatments based on natural sources (e.g. biopesticides) have experienced remarkable growth globally, but very few are registered for Ontario greenhouse crops, or field-grown crops. Ontario greenhouse cultivation and food processing generate appreciable amounts of commercially exploitable waste containing potential biopesticides. Moreover, greenhouse tomato crop residue and tomato pomace waste are generated as relatively clean streams after harvesting/processing or canning. These residues contain bioactive phytochemicals (e.g. saponins), which are known to be directly antifungal and insecticidal, but nothing is known of the quantity in Ontario varieties, the efficacy in controlling Ontario pests following applications and the potential economic return. Improvement in pest (disease and insect) management strategies for horticultural crops is a priority for organic producers.

We will determine the feasibility of creating preventative crop protection treatments with repellent and plant defence inducing properties from tomato crop and canning residues for use in Ontario’s greenhouse industry. Tomato vine residues will be provided by an organic greenhouse and pomace by an organic processor. The ability of these phytochemicals to control fungal and insect pests common to Ontario greenhouse production through increased host plant defenses and repellent activity, respectively, will be evaluated with in vitro and in-vivo bioassays and in greenhouse experiments. Treatments will be applied in various doses by drenching the potting media or by spraying the foliage. Plants inoculated with pathogens will be assessed for disease symptoms. Bioassay tests will be performed with three common insect pests, by applying extracted saponins to freshly cut leaves at various rates and measuring repellence and toxicity. This project will create value-added products from agricultural residues, attract industrial partners and develop new made-in-Ontario biopesticides for organic greenhouse pest control.

Final Report Summary

A large amount of agricultural residue is generated around the world annually, representing an untapped resource for the development of new bioproducts. Valuable bioactive phytochemicals such as saponins and essential oils are found in appreciable quantity in plant biomass, including agricultural residues. Saponins and essential oils extracted from plants, such as tomato vines or spent hops, could be effective as crop protectants, for control of both fungal and insect pests...

Keep Reading [PDF 6.10 MB]

Publications and Other Resources

Podcast: Organic Science Conversations- Saponins for Controlling Pests in Greenhouses


Activity Researchers

Name   Organization/Location
Dr. Simon Lachance (Activity Leader) University of Guelph – Ridgetown Campus
Dr. Rob Nicol University of Guelph – Ridgetown Campus
Dr. Ian Scott AAFC - London