Please find attached the spore report and trap location maps for spore trapping in 2023.
Potatoes
Take home message: Spores of late blight have been detected at two locations this year.
This week at one trap north of Paul and on the 15th and 16th June at Parma. Therefore, the risk of late blight this year is higher than in 2020 and 2021 when no spores were detected at all. Please note spores were detected this time last year at several sites but no late blight disease was observed in 2022 due to low humidity and high temperatures. We recommend that people be vigilant for late blight in their scouting as well as pay attention to periods of weather with high humidity (80 percent +) going forward.
This week Phytophthora infestans (late blight) was detected on 1 of 4 days at the North Paul site.
Alternaria solani was tested for on trap samples from Parma, Aberdeen and Aceqia only and it was not detected at any of those three sites.
Ten hours or more of 80 percent plus humidity over two consecutive days were observed at the Parma, Shelley and Rupert weather stations. Previous work has shown these weather conditions plus the detection of spores means there is a risk of late blight occurring. Therefore, growers in the Paul/Rupert area should be cautious of this risk.
Further information on late blight is available here:
https://www.potatogrower.com/2023/06/importance-of-scouting-for-late#:~:text=Scouting%20allows%20growers%20to%20make,fungicide%20applications%20for%20optimal%20effectiveness.