Bacillus pumilus strain QST 2808

Bacillus pumilus strain QST 2808 is a highly effective biological control agent belonging to the group of spore-forming soil bacteria. Its primary mechanism involves colonizing the plant surface and forming a protective biofilm.

The strain produces a diverse array of lipopeptides, including iturins and surfactins. These natural compounds disrupt the cell membranes of pathogenic fungi and bacteria, effectively neutralizing them before infection can occur.

Beyond direct antagonism, the strain is known to induce systemic acquired resistance (SAR) within the host plant. This process boosts the plant's natural immune system, making it inherently more resistant to future pathogen attacks.

Active colonization of the rhizosphere and phyllosphere is crucial to its action. By occupying these ecological niches, the bacteria compete with pathogens for nutrients and space, significantly limiting their ability to proliferate.

As a biological product, it is environmentally friendly and offers a safe alternative to conventional synthetic pesticides, supporting sustainable agricultural practices and the production of residue-free crops.

This strain is widely used to control a broad spectrum of diseases caused by fungi and bacteria. It is particularly effective against various species of powdery mildew affecting fruit and vegetable crops.

The product provides strong protection against grey mold (Botrytis), which is a common challenge in greenhouse production. It is also utilized to combat soil-borne diseases like Fusarium and Verticillium wilts.

Bacillus pumilus QST 2808 shows efficacy against Rhizoctonia, a pathogen that causes damping-off and root rot in early seedling development, helping to maintain optimal plant population density.

The strain is also active against certain bacterial leaf spots and blights, providing an additional layer of defense where chemical fungicides may face issues with resistance or regulatory limitations.

• Powdery mildew
• Grey mold (Botrytis)
• Fusarium and Verticillium wilts
• Rhizoctonia
• Bacterial leaf spots

Application rates for Bacillus pumilus QST 2808 depend on the crop type, target pathogen, and the specific application method (foliar spray, soil drench, or seed treatment).

For foliar applications, the concentration must ensure thorough coverage of the plant surface. Regular application schedules, adjusted to the crop growth stage, are essential to maintain a continuous protective barrier.

When used as a soil drench or seed treatment, the product should be applied in a way that encourages rapid colonization of the root zone, ensuring the bacteria establish themselves before the plant faces high disease pressure.

The frequency of application can be adjusted based on environmental conditions; during periods of high humidity and disease risk, intervals between treatments should be shortened to maintain efficacy.

Because it is a biological agent with no significant residue issues, it can be applied throughout the growing season, including right up to harvest, providing growers with high flexibility.

The primary limitation is the biological nature of the product, which requires specific temperature and moisture conditions to thrive. Extreme environmental stress may reduce the activity of the bacteria.

Avoid tank-mixing the product with strong bactericides or copper-based fungicides, as these chemicals can be toxic to the Bacillus pumilus bacteria and compromise the efficacy of the treatment.

Standard safety precautions should be followed during handling, including the use of protective clothing and gloves. While not highly toxic, contact with concentrated formulations should be minimized.

The product should be stored in a cool, dry environment away from direct sunlight. Improper storage conditions can decrease the shelf life and the concentration of viable bacterial spores.

Compatibility testing is recommended before mixing with other plant protection products to ensure that the chemical environment does not interfere with the survival and performance of the beneficial bacteria.