News Diseases Cereals
Cereal rust risk is low for the Prairies

As of May 21, 2019, wind trajectory reports show that the risk for cereal rust is low in the Prairie region, according to latest report from the Prairie Crop Disease Monitoring Network (PCDMN).

Wind trajectory models are used as an “early-warning system” for pests and diseases. Rust spores usually travel with the wind from the U.S. into Canada. Throughout 2019, the PCDMN will release a series of weekly cereal rust risk reports throughout May and June.

Reem Aboukhaddour, a research scientist with Agriculture and Agri-Food Canada (AAFC) in Lethbridge, Alta., previously explained in an article about stripe rust scouting that the rust situation in the U.S. is a good indicator of disease pressure in Canada. “Rust spores usually travel with the wind from the U.S. into Canada, if the inoculum arrives early enough, and if weather conditions are favourable for rust infection and development, we may get bad disease regardless if the pathogen overwinters locally or not.”

Below is a synopsis of the weekly cereal rust risk report for the week of May 21, 2019, showing that risk is low and scouting for rust is not urgent unless producers had noticed stripe rust development on winter wheat in the fall of 2018.

Pacific Northwest winds

Given limited stripe rust development in the Pacific Northwest (PNW), a low number of recent wind trajectories from the PNW, cool and relatively dry Prairie weather conditions, and early stages of Prairie crop development, as of May 21, 2019, the risk of stripe rust appearance from the PNW is limited and scouting for this disease is not urgent.

Texas-Oklahoma corridor

Although leaf and stripe rust development continues in this corridor, especially Oklahoma, the disease is mainly affecting the lower canopy at generally low levels. In addition, crops are advancing towards maturity and thus will become less of a source of rust inoculum. There have been a low number of recent wind trajectories from this area, cool and relatively dry Prairie weather conditions, and early stages of Prairie crop development. Thus, as of May 21, 2019 the risk of leaf and stripe rust appearance from the Texas-Oklahoma corridor is low and scouting for these diseases is not urgent.

Kansas-Nebraska corridor

Although leaf and stripe rust development continues in this corridor, it is at low-moderate levels and mainly in the middle portions of crop canopies, recent moisture conditions may promote further development. There have been a low number of recent wind trajectories from this area, cool and relatively dry Prairie weather conditions, and early stages of Prairie crop development. Thus, as of May 21, 2019 the risk of leaf and stripe rust appearance from the Kansas-Nebraska corridor is low and scouting for these diseases is not urgent, but further development of rust in these regions may increase the risk.

Winter wheat scouting

Where farmers or consultants noticed stripe rust development on winter wheat in the fall of 2018, it is recommended to scout winter wheat fields that have resumed growth this spring. Scouting is especially critical where the variety being grown is susceptible to stripe rust. Currently, there are no early spring reports of stripe rust on winter wheat.

Agriculture and Agri-Food Canada and Environment and Climate Change Canada have been working together to study the potential trajectories for monitoring insect movements since the late 1990s. The full wind trajectories report, with weather and overwintering analysis, is available on the Prairie Pest Monitoring Network blog.