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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #373086
Research Project: Development of Elite Sugar Beet Germplasm Enhanced for Disease Resistance and Novel Disease Management Options for Improved Yield

Location: Northwest Irrigation and Soils Research

Title: Incidence, distribution, and pathogenicity of fungi causing root rot on the top surface of long-term outdoor sugar beet storage piles in Idaho

Author
item Strausbaugh, Carl

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/13/2020
Publication Date: 12/30/2020
Citation: Strausbaugh, C.A. 2020. Incidence, distribution, and pathogenicity of fungi causing root rot on the top surface of long-term outdoor sugar beet storage piles in Idaho. Phytopathology. 110:S2.93.

Interpretive Summary:

Technical Abstract: Sugar beet roots in Idaho are held in outdoor storage piles under ambient conditions which can lead to substantial sucrose losses and fungal root rot. The fungal rots associated with roots held inside piles has been recently established, but the incidence, distribution, and pathogenicity of fungi associated with root rot on the top surface has not been determined. Therefore, the fungal rot on the top surface of 14 Idaho sugar beet piles [tarped ventilated (TV) piles and piles with no tarps or ventilation (NTV) at 7 locations] was assessed in 9 one-square meter areas per pile using a stratified random sampling design in 2018-19 and 2019-20. Pathogenicity was evaluated through sugar beet root plug inoculations conducted in commercial storage buildings. Cladosporium spp. were the only fungi covering more than 1% of the root surface (2 to 48%) on top of NTV piles both years. The surface of roots after tarp removal on TV piles was also dominated by Cladosporium spp. (13 to 60%), but Penicillium spp. (0 to 35%), an Athelia-like basidiomycete (0 to 2%), and Botrytis cinerea (0 to 2%) were also frequently present. NTV piles always had less fungal growth than TV piles regardless of variable. Roots placed on the pile first had more fungal growth than those in other areas based on Cladosporium spp., the Athelia-like fungus, and total fungal growth. In the plug assay, B. cinerea caused the most rot, while the Cladosporium spp. led to little or no rot. Thus Cladosporium spp. seemed to largely be opportunistic fungi despite being the most prolific on the pile top root surface.