Fungal Disease Threatens Global Blueberry Crops, Morocco at Risk

There are two strains of this fungus originating from the eastern United States and identified in several regions of the world including Morocco, Peru and Portugal: one has attacked blueberry plantations in China, Mexico and California, and the other, more virulent, has spread to the Maghreb, particularly Morocco, and Southern Europe.

The case of Morocco is worrying, given the important role of blueberry crops in export agriculture. The fungus attacks the leaves, thus preventing photosynthesis and the growth of blueberry plants. According to the study, powdery mildew causes production declines and generates considerable losses for the global blueberry industry, estimated between $47 million and $530 million. For Morocco, these losses could be heavier, as several regions continue to depend on red fruit exports.

The fungus spreads due to international exchanges of infected plants affecting new growing areas. "If you ship plant material globally, you risk transporting this fungus with it," explains Michael Bradshaw, assistant professor of plant pathology at North Carolina State University. In Morocco, the climatic conditions, combining humidity and moderate temperatures, could favor the rapid spread of the fungus.

To prevent the disease, researchers have developed a public database to identify the different strains of powdery mildew. The goal is to allow farmers to report on the virulence of the strains present in their crops and their possible resistance to fungicides. In Morocco, a synergy of actions between the various stakeholders in the sector (researchers, producers and agricultural authorities) will be necessary to curb the progression of powdery mildew and save the red fruit industry.