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)
Exclusion nets have proven to be effective against nearly all of these insect pests, which means that it’s possible to develop apple growing practices in Québec that are not only neonicotinoid free, but also devoid of all pesticides (including acaricides, given that mite problems are a consequence of broad-spectrum insecticide use). Although the net exclusion microsystem studied in Québec since 2012 has demonstrated its effectiveness in controlling insect pests, some issues remain to be studied before it can be unreservedly recommended. Among these are the handling times for the nets, i.e., installation/removal and opening/closing, and the system’s profitability and durability over the long haul for various cultivars.
Researcher: Gérald Chouinard
The aim of this two-year project was to determine the efficacy of various pesticides in the field.
Researcher: Annabelle Firlej
This project assesse the influence of biotic and abiotic factors on the efficacy of spring flooding to developp a strategy of control for the blackheaded fireworm
Researcher: Daniel Cormier