b'If growers want to do spore trapping on their own farms, their costs woulding pathogens in the field, with PCR testing done in a laboratory to confirm any include the traps, the filters and the PCR tests. Banks says time will tell whetherpositive results. growers adopt this technology. Potato growers are very good at selecting andSome other provinces already have or are working on late blight forecasting adopting new integrated pest management tools that contribute to their farmssystems that include spore trapping. For example, Albertas system uses data from a sustainability. provincial network of spore traps along with weather data to forecast late blight risks. Spore traps are another component of an effective late blight managementThis type of approach would also make sense for Ontario, says Banks. strategy that includes planting healthy seed, early spraying, destroying volunteersI am sure a provincial network of spore traps in Ontarios potato-growing and cull piles, field scouting, and timely applications of late blight-specificareas would be welcome not only by growers but potato industry personnel as fungicides. well, she says. Weather data is also an important component of late blight Growers should make sure that new growth is always protected, she adds.management. In my opinion, it would be a very useful system to have available for After rainfall, water accumulates there, and new growth is an easy target forOntario potato growers. late blight. Their fields should be scouted twice a week. Destruction of cull pilesWould spore trapping for other important potato diseases make sense? Spore and volunteers is a must. If a field cannot be sprayed due to very wet soil, growerstrapping works well for airborne, explosive diseases like late blight, explains Banks. should consider aerial spraying. Some other potato diseases are endemic; their inoculum overwinters in the Banks says if spores are detected in their area and the weather is conducive tosoil and will develop each season in most fields. Early blight is a good example. It late blight, she recommends growers tighten spray intervals using late blight-spe- has a well-known development pattern. The symptoms develop first on the lower cific fungicides tank mixed with a broad-spectrum fungicide. leaves, and disease incidence is high if the crop is under stress. Growers need to apply the first fungicide spray before the vines close to protect the lower leaves. LOOKING AHEADSporometrics evaluated air samplers for early blight spores with limited success.The Ontario Potato Board is currently collaborating on a new two-year studyWhite mould and Botrytis grey mould overwinter in the soil as sclerotia, Banks to evaluate an in-field spore identification method. This year, Sporometrics isexplains. Spores produced during the season are blown to neighbouring fields, but validating loop-mediated isothermal amplification (LAMP), Banks says. LAMPthey are not explosive diseases on potatoes. Regular field scouting should provide performs PCR analysis in the field, which would be an advantage for early patho- timely information on their occurrence, and air samplers may be of some value.gen detection. It is also cheaper than traditional PCR, but less sensitive. The study will compare LAMP and conventional PCR methods when used withDRONE-BASED DETECTIONfilters from the spore traps. Brigitte Leblon, a professor at the University of New Brun-Banks says Phillip Wharton, a plant pathologist at the University of Idaho, hasswick (UNB), is leading a three-year study to use drone used LAMP to identify late blight and some other diseases in the field.imagery for late blight detection. The idea is to detect crop Dr. Wharton envisions LAMP could be used as a first line of defence in detect- infection before any symptoms are visible in the plants. In 2019, Banksis using this new-model Spornado, which hasan easier system to placeand remove the trap filters, in her research on late blight spore trapping. PHOTO: EUGENIA BANKS,ONTARIO POTATO BOARDFALL 2019 SPUDSMART.COM 47'