A microbiological approach to alleviate soil replant syndrome in peaches

Authors: NEWBERGER, DEREK - Colorado State University; MINAS, IOANNIS - Colorado State University; Manter, Daniel; VIVANCO, JORGE - Colorado State University

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2023
Publication Date: 5/30/2023
Citation: Newberger, D.R., Minas, I.S., Manter, D.K., Vivanco, J.M. 2023. A microbiological approach to alleviate soil replant syndrome in peaches. Microorganisms. 11(6). Article e1448. https://doi.org/10.3390/microorganisms11061448.
DOI: https://doi.org/10.3390/microorganisms11061448

Interpretive Summary: Replant syndrome is a global problem facing tree fruit and nut production in agriculture. Replant syndrome is characterized by reduced overall growth, production life, and yields of tree fruit/nut orchards. Scientists at Colorado State University and USDA ARS in Fort Collins, CO found that cover crops are an effective tool to shift the soil microbiome in soils prone to replant syndrome, and that cover crops can also increase peach biomass. Their research also reveals that soil sterilization can remove beneficial bacteria from soils that do not recover, even when cover crops are grown resulting in a negative impact on subsequent peach growth and biomass.

Technical Abstract: Replant syndrome (RS) is a global problem characterized by reduced overall growth, production life, and yields of tree fruit/nut orchards. RS etiology is unclear, but repeated monoculture plantings are thought to develop a pathogenic soil microbiome. This study aimed to evaluate a biological recipe that could reduce RS in peaches by developing a healthy bacterial microbiome. Soil disinfection via autoclave followed by cover crop growth and incorporation was found to distinctly alter the peach RS soil microbiome, but did not affect the RS etiology of RS-susceptible Lovell peach saplings. In contrast, non-autoclaved soil followed by cover crop growth and incorporation altered the soil microbiome to a lesser degree than autoclaving, but induced significant peach growth. Non-autoclaved and autoclaved soil microbiomes were compared to highlight bacterial taxa promoted by the cover crops prior to growing peaches. Beneficial bacterial species such as Bacillus megaterium, Gaiella occulta, Paenibacillus castaneae and Nitrospira japonica were promoted by cover crops when grown in non-autoclaved RS soil. At the end of the peach-growing cycle, bacterial species such as B. megaterium, G. occulta, N. japonica were still present in non-autoclaved peach bulk and rhizosphere RS soils for all cover crop histories. In addition, other species of beneficial microbes were cultivated exclusively in the rhizosphere of non-autoclaved soils by peaches such and Peribacillus simplex and Arenimicrobium luteum for all cover crop histories. In summary, the non-autoclaved regenerated soils showed continuous enhancement of beneficial bacteria at each cropping phase culminating in a highly enriched rhizosphere that alleviated RS in peaches.