Mechanized application of auxiliaries in large-scale ornamental plant greenhouses

inside a greenhouse

By: Émilie Lemaire, Agr, M.Sc., Project Manager, IQDHO

Beneficial organisms have been used for several years to control pests in ornamental crops grown in small-area greenhouses. However, the use of this pest management approach in large-scale operations is limited by the time it takes to spread predators manually onto the crops. To accelerate this process, mechanical application tools that blow biological control agents onto the crop are now available to Quebec growers. Until recently, it had not been verified whether these tools injured or even caused the death of the predators. To verify these possibilities, the IQDHO has launched a project to evaluate three devices: the Koppert’s Mini-Airbug blower, the Makita DUB182Z blower/vacuum adapted by Plant Products to spread predatory mites, and the “Entobot” drone from Canopée initially developed to release trichogramma (small parasitic wasps) on corn fields and forests.

During the first year of the project, testing took place on a warehouse floor. Preliminary tests with the drone have shown that significant adjustments will be required before using this device to spread predatory mites in greenhouses, so this technique was withdrawn from the project.

Neoseiulus cucumeris, a predatory mite marketed in a vermiculite carrier, was chosen as the test auxiliary. This species, which is most used to suppress thrips in a wide variety of greenhouse ornamental crops, is widely employed in vegetable crops. Experiments demonstrated that the two types of mechanical applicators tested would not significantly affect the viability of predators spread on a flat surface, regardless of the distance at which they are sprayed. In the second year of the project, predator viability was evaluated after an application on geraniums, gerberas and impatiens in large commercial greenhouses. The results obtained under these production conditions showed that the Mini-Airbug and the Makita Predator Blower did not induce higher mortality than a manual spreading. A summary economic analysis showed that the purchase of the Mini-Airbug or Makita blower can quickly pay for itself, as the spreading time can be reduced by up to 85% with these devices compared to manual spreading. These results will have a great impact on the adoption of biological control by companies producing ornamental plants in large greenhouses, thereby reducing the use of insecticides and the associated risks.

“This project was carried out as part of component 4 of the program Prime-Vert—Appui au développement et au transfert de connaissances en agroenvironnement with financial assistance from the Ministère de l’Agriculture, des Pêcheries et de l’Alimentation through the Stratégie phytosanitaire québécoise en agriculture 2011—2021.”

For more details, see the final project report:

Link to the project summary sheet:

The IQDHO would like to thank the many contributors to this project: Anatis Bioprotection, Plant Products, Canopée, Koppert, La Ferme Grover Inc., Willy Haeck et fils Inc., Serres et Jardins Girouard Inc. and the ITA in Saint-Hyacinthe.

Makita Predator Blower