Development of new microbial solutions combining biofertilization and biocontrol of bacterial canker and fungal infections in tomatoes

There are nearly 500 greenhouse businesses in Quebec, half of which are involved in vegetable production. These Quebec greenhouse growers produce mainly tomatoes, as well as cucumbers, lettuce, peppers, etc.

Infectious diseases are a major limiting factor in vegetable production, leading to serious yield reductions and severe economic losses. Tomato, the most cultivated vegetable in the world, is the target of many infectious agents. Fungal diseases include alternaria, olive mold, vascular fusariosis, downy mildew, gray mold, powdery mildew, anthracnose and septoria leaf spot. The most common bacterial diseases affecting tomatoes are bacterial spot, fly speck and bacterial canker.

Bacterial canker of tomatoes, caused by the Clavibacter michiganensis bacteria, affects tomato production worldwide. This disease is one of the most important and destructive, especially in greenhouse production of tomato grown in soil or hydroponics. This plant pathogen is difficult to control and yield losses of 20 to 85% due to canker and wilt are possible.

In Quebec, the organic food market is growing significantly. The so-called "organic" agriculture is based on a combination of practices that are compatible with environmental protection, health, animal welfare and social acceptability. It excludes the use of pesticides and synthetic fertilizers.

Since microorganisms colonize plants and promote the assimilation of virtually all nutrients by plants, the amendment of appropriate rhizobacteria can promote effective biofertilization, thereby reducing the need for synthetic fertilizers. In addition, some of these plant-bound microorganisms can exclude plant pathogens, thus protecting plants from infection. The use of such biopesticides and biofertilizers is becoming increasingly popular, not only in organic agriculture.

The main objective of the project is therefore to develop products of microbial origin combining biofertilization and biocontrol of bacterial canker and fungal infections in tomato with a multiple, specific and efficient mode of action. Thanks to their multiple modes of action, different from those of conventional chemical fungicides, antagonistic bacteria can offer an effective and alternative solution to control fungal and bacterial infections in organic tomato greenhouse cultivation. Considering that organic agriculture is becoming more and more popular in order to produce healthier and eco-friendly food, biological approaches to plant pathogen control and biofertilization are advisable. Finally, it should be noted that this is perfectly in line with the objectives of the 2020-2030 Sustainable Agriculture Plan recently announced by the ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec (MAPAQ).