Cool and dry conditions limited the incidence of plant disease in some areas last year, but producers should be on the lookout for what might reappear this season, says Kelly Turkington, plant pathologist with Alberta Agriculture in Lacombe. Turkington gave an overview of diseases that were problematic in 2009 at the Agronomic update in Stettler.
Turkington said stripe rust was limited in central Alberta, but showed up in spring and winter wheat in southern Alberta, he said. Turkington encouraged producers in susceptible areas to choose stripe rust-resistant varieties.
“If you have that option, pick a resistant variety because that’s going to mitigate all of your risk from stripe rust. If you can’t, it’s recommended that you keep on top of that crop and scout on a regular basis and use a fungicide if needed,” he said. Producers should spray as soon as they see any symptoms of stripe rust.
Barley leaf spot diseases were a minor issue, and rates of disease remained lower than in previous years. The disease showed up in fields later in the year, due to late precipitation in June and July. The disease showed up in tight rotations where barley was grown after barley, said Turkington. Key strategies to prevent both barley and wheat-leaf diseases include crop rotation, choosing resistant varieties and targeted application of fungicide.
Wheat leaf spot diseases were lower in previous years in central Alberta. There was a fair amount of powdery mildew in the research plots in Lacombe, while tan spot was the main issue in winter wheat in southern Alberta. Tan spot can be identified by the presence of oval lesions with a darker-coloured interior that affect both yield and grade.
Common root rot in barley was more severe in central Alberta than in 2009. The disease was found in all fields surveyed, and levels ranged from trace levels to very severe. The problems were found to be related to tight rotations and the use of susceptible varieties.
“Once you start comprising root health with root diseases or poor agronomics, you basically influence water and nitrogen use efficiency so you want to make sure you keep root health,” Turkington said.
Fusarium head blight in wheat was found in southern Alberta this past summer and was mainly an issue in hard red spring wheat, but was a limited issue in other regions of the province. Fusarium also has an impact on barley and malt barley, said Turkington.
Diseases in canola were limited by some of the dry conditions throughout the province. Sclerotinia was much less of an issue, but became an issue with late-seeded crops or in later developing parts of the field. Short rotations continue to create complications that may lead to more virulent strains of blackleg and clubroot.
Pulse diseases of concern included root rot and mycosphaerella.