Strawberry growers face persistent challenges from soilborne diseases, weeds and rising costs associated with chemical fumigation.

A new study published in PLOS ONE by researchers from Virginia Tech and the Institute for Advanced Learning and Research (IALR) offers a promising alternative: integrating anaerobic soil disinfestation (ASD) with beneficial microbes to improve crop health and fruit quality while reducing reliance on synthetic fumigants.

Read the Full Study 

The Challenge

Fruit rot diseases such as anthracnose and Botrytis, along with weed pressure, can significantly reduce strawberry yields and quality. For decades, growers have relied on chemical fumigation to manage these issues.

However, health concerns, regulatory restrictions and high costs have made fumigation increasingly impractical, especially for organic and small-scale growers.

“As a way of integrating biological microbes with chemical fumigation and alternatives such as ASD, we are adding treatments to the toolbox and providing choices (like never before) to our strawberry growers.” – Jayesh Samtani, Ph.D., Associate Professor & Small Fruit Extension Specialist, Virginia Tech

The Study

The two-year field trial was conducted at Virginia Tech’s Hampton Roads Agricultural Research and Extension Center. Researchers compared the following three preplant treatments, each of which was combined with post-plant inoculations of beneficial microbes, including Bacillus velezensis IALR619 and a commercial product, TerraGrow.

  • ASD using brewer’s spent grain
  • Traditional fumigation with Pic-Clor 60
  • Non-fumigated control

ASD involves incorporating an organic carbon source into the soil, irrigating to field capacity and covering with plastic mulch to create anaerobic conditions. This process suppresses pathogens and weeds without the use of chemicals. Beneficial microbes act as natural biocontrol agents and growth promoters.

Read the Full Study 

Building on Endophyte Research

This work builds on years of research by IALR’s Plant Endophyte Research Center, which houses a library of more than 2,000 characterized bacterial endophytes. These naturally occurring microbes have repeatedly demonstrated their ability to act as biostimulants, boosting plant growth and nutrient uptake, and as biocontrol agents, reducing disease pressure in crops such as lettuce, cucumber and now strawberries.

Previous studies have shown endophytes can increase yields by 20% or more in controlled environments and improve resilience under stress.

“Finding real-world and practical solutions for common problems faced by growers is at the heart of our research program. In this case, partnering with Virginia Tech has led to measurable improvements in strawberry production in the state of Virginia.” – Dr. Scott Lowman, Vice President, Applied Research, IALR

Key Findings

  • Disease Suppression: ASD significantly reduced anthracnose fruit rot and Botrytis compared to untreated controls.
  • Weed Management: ASD lowered weed density and biomass, offering an alternative to herbicides.
  • Fruit Quality: Inoculation with B. velezensis improved fruit firmness, a key quality trait for consumers.
  • Integrated Benefits: Combining ASD with beneficial microbes enhanced disease control and fruit quality without synthetic fumigants.

“This further collaboration research will combine ASD and beneficial microbes in strawberry production based on our previous research funded by the USDA Specialty Crop Block Grant Program and administered by the Virginia Department of Agriculture and Consumer Services.” – Dr. Chuansheng Mei, Chief Scientist, IALR

Why It Matters 

This integrated approach is particularly valuable for organic and resource-limited growers who cannot use chemical fumigants. By leveraging biological processes, growers can reduce input costs, minimize environmental impact and maintain high-quality fruit production. 

Future studies will focus on optimizing ASD protocols, refining microbial applications and exploring site-specific recommendations. Researchers aim to make these strategies practical and scalable for diverse production systems. 

The Research Team  

  • Dr. Chuansheng Mei, Chief Scientist, IALR 
  • Dr. Scott Lowman, Vice President, Applied Research, IALR 
  • Robert Chretien, Laboratory Research Associate, IALR 
  • Jayesh B. Samtani, Associate Professor and Small Fruit Extension Specialist 
  • Baker D. Aljawasim, Ph.D. Student, Virginia Tech   
  • Patricia Richardson, Research Specialist Sr., Virginia Tech