Abstract Detail

Host/Plant Pathogen Interactions and Plant Health Management

Tedford, Sherri [1], Burlakoti, Rishi [2], Trueman, Cheryl [3].

Aerobiology and epidemiology of Cercospora beticola in Southwestern Ontario.

Cercospora leaf spot (CLS) is the most detrimental disease of sugarbeet in temperate climates. Adding spore activity information to the BEETcast™ advisory tool may optimize disease risk estimates and fungicide application timing. Airborne Cercospora beticola (Sacc) spore levels were monitored in six hour blocks from April-October, 2014, using Burkard volumetric spore traps in Pain Court (PC) and Ridgetown (RT), Ontario sugarbeet fields. Weather data was collected in real-time at each location. C. beticola spores were first detected on May 2 in RT and June 11 in PC, and daily totals peaked on September 20 (RT=1204; PC=1433). CLS severity reached 60 (RT) and 16 (PC) % by harvest. Relative humidity was correlated with spore activity (P ≤ 0.001) at both locations 0, 6, and 12 h before spore capture (r = 0.1234 to 0.3253). Leaf wetness duration was correlated with spore activity (P ≤ 0.001) at both locations 6 and 12 h before spore capture (r = 0.1484 to 0.2980).Temperature was correlated with spore activity (P ≤ 0.001) at all times in RT (r = 0.2290 to 0.3785). In PC temperature was correlated with spore activity (P = 0.0115) at 0 h (r = 0.0974). Rainfall was not correlated with spore activity at either location at any time.Results suggest that relative humidity, leaf wetness duration, and temperature may be important predictors of spore activity that could be further incorporated into the BEETcast™ advisory tool. Further analysis is underway to better understand relationships among weather variables, spore concentration, and CLS.

1 - University of Guelph, Department of Plant Agriculture, 120 Main Street E, Ridgetown, ON, N0P 2C0, Canada
2 - Weather Innovations Consulting LP, 7159 Queens Line, Chatham, ON, N7M5T1, Canada
3 - University of Guelph, 120 Main Street E, Ridgetown, ON, N0P 2C0, Canada

Keywords:
Cercospora leaf spot 
Cercospora beticola 
spore aerobiology
weather relationships
disease risk estimates .

Presentation Type: Oral Paper:Papers for Topics
Session: 65
Location: Salon 9/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 11:45 AM
Number: 65007
Abstract ID:516
Candidate for Awards:None