Apple growers apply fungicide treatments every year to suppress apple scab caused by the fungus Venturia inaequalis. These treatments must be repeated depending on the infection risk, the appearance of new leaves since the previous treatment, and wash off due to rainfall. Treatments are generally carried out before a rainfall (protection). However, during periods of high growth or periods of prolonged rainfall, treatment strategies during (spore germination) and after (post-infection) rainfall may be needed to prevent high-risk infections. More than 20 different products to control scab, belonging to a dozen distinct categories, are registered in Canada. Choosing the right product to apply can be tricky because there is no chart comparing their actual performance for each application strategy. Furthermore, most labels do not clearly indicate the dosage required as a function of tree size or type of equipment used. To overcome these shortcomings, this project aims to develop a new scab control strategy based on selecting the lowest-risk products that best fit the circumstances at hand, and tailoring the doses accordingly. Together with a project already underway examining wash off, this project will provide growers with a complete picture of the available control tools, and a comprehensive comparison of fungicides with respect to their resistance to washout, their efficacy on growing leaves, and their effectiveness with regard to protection, germination, and post-infection. This project is also part of an applied research program on spraying that will enable growers to adjust the dose of a selected product, if necessary, according to their orchard type and the performance of their sprayer.
From 2020 to 2023
Pest, weed, and disease control
These results will make it easier for growers to apply lower-risk fungicides at optimal doses.
Ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec
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 project is to measure the potential of automated traps and extrapolate it to an apple-monitoring network.