Soil chemistry and biological manipulation to prevent losses from Phytophthora root rot
Phytophthora organisms that cause root rot of Christmas trees have spores that can persist in the soil for several years. One approach to protect Christmas trees from infection could be to create conditions in which the disease organism either cannot persist, because antagonistic microorganisms destroy it, or to change the soil chemistry to interfere with the infection process, specifically by elevating calcium levels in soil. Tests conducted in Connecticut in 2022 and 2023 did not find effective ways to take advantage of these processes. Subtle improvements in growth were observed through inoculation of roots with a product containing a strain of Streptomyces. Tree growth was inhibited and color was poorer when partly decomposed wood chips were incorporated into the soil. These effects might be explained by depletion of available nitrogen from the soil. Nitrogen depletion effects due to incorporation of wood chips were independent of ultimate mortality of trees challenged from exposure to phytophthora. Growers should rely on conventional methods such as raised beds, improved drainage, and resistant plant species or accessions to mitigate the risk of losses due to root rot.
- Project ID22-02-CAES
- CategoriesDisease Management
- Growing Region(s)Northeast
- Tree SpeciesFir
- Investigator(s)Cowles
- Institution(s)The Connecticut Agricultural Experiment Station
- Research Year2022
- Publication Year2024
- ReportDownload 📁