Witches’ broom is a recurring problem in in all highbush blueberry fields. It was particularly widespread in 2016. However in Québec the disease has never been found on the witches’ brooms themselves. The brooms are just a symptom. According to the literature, the disease is probably caused by a rust fungus. Rusts are peculiar in that they complete their life cycle on two separate hosts. In the case of witches’ broom rust, the hosts are highbush blueberry and balsam fir. In balsam fir, the disease causes needle rust. The spores are often observed in July, but the beginning and end of the sporulation period has not been determined in Québec. Witches’ broom rust causes economic loss in both these hosts. The aim of the project was to determine whether the witches’ broom symptom on blueberries is really caused by the rust Pucciniastrum geopertianum, which attacks balsam.
Pest, weed, and disease control
This project will help growers reduce economic losses due to witches’ broom, a problem present in all blueberry fields.
Ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec | Appui au développement de l'agriculture et de l'agroalimentaire en région (PADAAR)
The apple leafcurling midge is a new apple pest in Québec. The aim of the project is to explore the pest’s phenology, establish variable economic injury thresholds, and incorporate the results into a phenology model in CIPRA.
Researcher: Daniel Cormier
IRDA is in charge of the economic analysis for this project which purpose is to examine the impact of flower plantings on bumblebee biodiversity in apple orchards in southern Québec.
Researcher: Luc Belzile