Foxglove aphids are problematic for greenhouse growers and many believe that commercially available natural enemies offer low efficacy, leaving them with no other choice but to use pesticides. In an effort to mitigate this problem, Vineland Research and Innovation Centre (Vineland) completed a three-year project to provide growers with an integrated pest management (IPM) strategy against these aphids in greenhouse ornamentals.
If aphid numbers increase, biopesticides or predators can be used as supporting strategies to minimize populations. “In addition to aphid predators that are already commercially available, we found three new suitable biocontrol agents: biopesticide Met52, a pea protein and a novel predatory mite,” said Buitenhuis. “These agents provided good control levels against foxglove aphids and were compatible with A. ervi.”
Clean-up of crops is the final step and pesticide sprays can be used before shipment if there are remaining aphids. Beleaf and Endeavour are good final clean-up spray options. Note that the pesticide Enstar is not compatible with A. ervi.
Cultural management practices can also help decrease aphid populations. The use of screens over vents and the removal of infested weeds from inside and outside the greenhouse prevent entry of aphids. Reduction of nitrogen fertilizer rates may also help decrease aphid population growth and damage to the crop.
“Our results helped us formulate practical recommendations for a successful foxglove aphid IPM strategy,” said Buitenhuis. Results from various trials also validated these recommendations amounting to a 50 per cent reduction in pesticide use against foxglove aphid.
“Our IPM strategy will help growers respond to emerging pest issues while maintaining high production value and ensuring the Canadian floriculture sector remains competitive,” said Buitenhuis.
In the final phase of this project, Vineland is doing extensive outreach to growers and biocontrol companies through industry presentations/posters/fact sheets, greenhouse trials, publication of scientific articles and updates to industry resource www.greenhouseipm.org.
This project was supported by the Canadian Ornamental Horticulture Alliance (COHA) research and innovation cluster and funded in part through the AgriInnovation Program under Growing Forward 2 (GF2), a federal-provincial-territorial initiative. The Agricultural Adaptation Council assists COHA in the delivery of this research and innovation cluster.
This research was led by Michelangelo La Spina, PhD, Research Associate at Vineland, in partnership with Sarah Jandricic, Greenhouse Floriculture IPM Specialist, Ontario Ministry of Agriculture Food and Rural Affairs, the Quebec Institute for the Development of Ornamental Horticulture (IQDHO), Vanleeuwen Flower Farms Ltd. in Ontario and Les Serres Arundel in Québec.
Vineland Research and Innovation Centre
Rose Buitenhuis, PhD
Research Scientist, Biological Control
905-562-0320 x749
rose.buitenhuis@vinelandresearch.com
vinelandresearch.com