Trial anaerobic soil disinfestation combined with soil inoculants for fruit rot management in strawberries

Experimental Set-Up:

• Researchers established a split-plot experiment at the Hampton Road Agricultural Research and Extension Center (Virginia Beach, VA) in 2022.
  • Pre-Plant (Main Plot) Treatments:
    1. Nontreated control
    2. Chemical fumigation with Pic-Clor 60 (1,3-Dichloropropene and chlorpicrin)
    3. Anaerobic soil disinfestation (see below)
  • Post-Plant (Split-Plot) Treatments:
    1. Nontreated control
    2. Bacillus velezensis soil inoculant
    3. TerraGrow: a commercial Bacillus inoculant
    4. TerraGrow + OxiDate 5.0 fungicide (hydrogen peroxide + peroxyacetic acid)
• Anaerobic soil disinfestation was performed by broadcasting brewer’s spent grain and paper mulch at about 2 tons/acre each prior to soil incorporation, bed formation, and plastic application. Soils were then drip irrigated beneath the plastic to 23% volumetric water content (as measured with a moisture probe), and allowed to undergo fermentative decomposition for 21 days.
• Planting holes were punched in the plastic film for both pre-plant treatments, and strawberries (var. ‘Chandler’) were seeded. Strawberries received standard post-plant fertilization and irrigation throughout the growing season.
• Post-plant microbial inoculant treatments were applied as soil drenches directly into the planting holes multiple times during the fall and spring.

Data Collection:

• Soil moisture, temperature, and oxidation-reduction potential sensors collected data throughout the experiment.
• Strawberry yield, including total yield, unmarketable yield, and damaged fruit from anthracnose and botrytis (two common types of fruit rot), was collected throughout the experiment. Researchers tested some marketable fruit for fruit firmness, pH, and total soluble solid content.
• Weed emergence in strawberry planting holes was also monitored.