|Hewavitharana, Shashika - Washington State University|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2017
Publication Date: 12/1/2017
Citation: Hewavitharana, S.S., Mazzola, M. 2017. Deciphering potential mechanisms of anaerobic soil disinfestation (ASD)-mediated control of Pratylenchus penetrans . Phytopathology. 107(Suppl.5), 47.
Technical Abstract: Pratylenchus penetrans is a component of the apple replant disease (ARD) causal pathogen complex. The potential role for biological mechanisms contributing to ASD-mediated suppression of P. penetrans was examined in greenhouse study using orchard soil with a history of ARD. Populations of P. penetrans were amplified by cultivating ARD soil with apple seedlings. Subsequently, ASD was applied using orchard grass (20 t ha-1), and half of the treated soil was pasteurized to eliminate biological elements that may have been recruited by ASD. Nematodes extracted from seedling roots were used to infest pasteurized (ASD-P), non-pasteurized (ASD-NP), and no-treatment control (NTC) soil and planted with apple seedlings. Seedlings planted in ASD-NP soil had significantly lower P. penetrans root populations than ASD-P indicating a contribution of biology to system resilience against re-infestation. In a separate trial a nylon mesh barrier was placed to separate ASD-P, ASD-NP, NTC, and pasteurized control (PC) soils from P. penetrans infested soil allowing nematode migration into the treated soil but prevented root penetration. Treated soils were planted with apple seedlings. ASD-NP and ASD-P had significantly lower root nematode density compared to NTC and PC inside the mesh barrier. This finding indicates that PC soil was prone to re-infestation in a similar manner to that observed for fumigated soils, whereas ASD treated soil was resistant to re-infestation by P. penetrans.