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)
IRDA drew up a list of insects and mites in Québec known to be or likely to become resistant to pesticides.
As part of this project, the soil water status at a chosen blueberry farm will be monitored at 40 spots over the course of the production year. We will seek to identify the relationship between water extraction, physicochemical and environmental factors, and yield levels that could help explain yield variability.
Researcher: Carl Boivin
An attract and kill technique to control plum curculio was recently proposed by U.S. researchers, but it is very little used in orchards and virtually unknown in Québec.
Researcher: Gérald Chouinard