Organic apples from Quebec are not exempt from all pesticides, because apple trees must face the multiple pests likely to colonize orchards. But, unlike traditional cultivation, organic apple growing only uses substances from natural processes or mechanical or manual processes.
“All synthetic pesticides are banned,” summarizes Pierre-Manuel Plante, owner of an organic orchard in Trois-Rivières. We use mineral oils that will asphyxiate the eggs of certain insects. We also apply clays, such as kaolin, which will whiten the trees without affecting their photosynthesis, but which make them less detectable by pests, who will therefore have difficulty spotting them. To combat the codling moth, “we can spray viruses. When the larva of this butterfly eats the leaves of the apple tree, it is then infected by these viruses,” explains the trained agronomist.
For weed management, highly concentrated vinegar can be used, but its effectiveness is very limited. “For our part, we have installed geotextile membranes. However, we must weed by hand or mechanically two or three times per season around the trees,” says Mr. Plante.
To slow down fire blight, “we can only intervene with a yeast that must be sprayed early enough so that it can colonize all the apple blossoms before the bacteria responsible for this disease is introduced into the orchard by insects. The yeast will then be able to compete with the bacteria,” he explains. And to treat scab, potassium bicarbonate is mainly applied.
As fertilizers, only fertilizers of natural origin can be used, such as composts and dry and granulated manures from organic farms. In addition, there are standards to be respected in terms of biodiversity.
“All of these products are very expensive and less effective than traditional products,” says Plante.