Reviewing the Current Understanding of Replant Syndrome in Orchards from a Soil Microbiome Perspective

Replant syndrome (RS) of fruit and nut trees causes reduced tree vigor and crop productivity in orchard systems due to repeated plantings of closely related tree species. Although RS etiology has not been clearly defined, the causal agents are thought to be a complex of soil microorganisms combined with abiotic factors and susceptible tree genetics. Different soil disinfection techniques alleviate RS symptoms by reducing the loads of the deleterious microbiome; however, the positive effect on crop growth is temporary. The goals of this paper are: (1) to conceptualize the establishment of the syndrome from a microbiome perspective and (2) to propose sustainable solutions to develop a beneficial microbiome to inhibit the onset of RS.