Manitoba Agriculture says more reports of suspected Phytophthora Root Rot in soybeans have come in. Most of the cases are located in the Red River Valley, but there is also a suspected case in southwestern Manitoba.   At this time of year, Phytophthora Root Rot is not always easily distinguishable from other root rots and Manitoba Agriculture encourages producers to send in suspected samples to the Crop Diagnostic Lab for identification, noting it's best that sample plants not be completely necrotic as living tissue is required in order to isolate the pathogen from the infected plants.

Meantime, producers in the southwest are deciding whether to spray a fungicide for Fusarium Head Blight (FHB) in wheat.

Manitoba Agriculture says crops in that region are at, or near, the flowering period but risk maps indicate a low risk for FHB infection at this point in time in western Manitoba. The ideal temperatures for Fusarium infection are between 15 and 30 degrees Celsius and Manitoba Ag says over time, temperatures coupled with humidity or precipitation may still lead to infection.

With canola also nearing the flowering period, many producers are considering fungicide application for Sclerotinia.   Plant Pathologist, Holly Derksen, says that Manitoba Agriculture doesn't produce risk maps for Sclerotinia in canola, however growers in southern Manitoba can use the North Dakota State University Sclerotinia risk maps if they are interested.   She says using the "pant leg" test is a good method for assessing Sclerotinia risk.

"Walking through your crop, are your pant legs coming out dry at ten a.m.? There's probably not enough moisture for Sclerotinia to be a large issue. However, if they're still coming out wet at one p.m. or two p.m., there's more than enough humidity and moisture within the canopy to produce the spores and have infection."

Manitoba Agriculture says the forecast temperatures in the low 30's for the next week will also play a role in the fungicide decision. Hot and dry conditions are not conducive to Sclerotinia infection or symptom development, however they can impact fungicide application.