If composts could be used successfully for disease control, growers would be able to reduce inputs of chemical fungicides, thus reducing costs and associated impacts on the environment.
impact statement issue
Composts have been used in agriculture for millennia and are important tools for maintaining soil health. They have been shown repeatedly to suppress many different diseases. However, the efficacy of composts for disease control may vary depending on batch, feedstock, and site. This inconsistency has been a major roadblock to grower implementation and the integration of compost amendments effectively into organic agriculture. Although the microbial nature of disease control is known, the reasons for such extreme variability are not understood. Our work is aimed at understanding this microbial variability in an attempt to make compost more predictably disease suppressive. Results from this project will greatly facilitate grower adoption and implementation into agricultural production systems.
impact statement response
Our work has already revealed that a great source of variability is the plant itself. Diseases caused by some damping-off pathogens are better suppressed by composts on some plants than others. We suspect that part of this variation results not only from different groups of microbes associating with different plants, but also the suppressive activities of specific microbes are altered in the presence of some plants and not others. Our work further reveals that the site of disease control is on the plant surface, and generally does not occur in the absence of plants.
impact statement summary
Work is underway to better understand how compost-dwelling microbes reduce damage from destructive seed- and root-infecting pathogens.\n
