In 2019, the PCDMN will release a series of weekly Cereal Rust Risk Reports throughout May and June. Information related to trajectory events based on forecast and diagnostic wind fields and cereal rust risk is experimental, and is OFFERED TO THE PUBLIC FOR INFORMATIONAL PURPOSES ONLY.
Background: Agriculture and AgriFood Canada (AAFC) and Environment and Climate Change Canada (ECCC) have been working together to study the potential of trajectories for monitoring insect movements since the late 1990s. Trajectory models are used to deliver an early-warning system for the origin and destination of migratory invasive species, such as diamondback moth. In addition, plant pathologists have shown that trajectories can assist with the prediction of plant disease infestations and are also beginning to utilize these same data. An introduction will be presented of efforts to identify wind trajectory events that may bring rust urediniospores into Western Canada from epidemic areas in the central and Pacific northwest (PNW) regions of the USA. Identification of potential events as well as an assessment of epidemic severity from source locations, and prairie weather conditions, will be used to assess the need for prompt targeted crop scouting for at-risk regions of the Canadian Prairies.
This week, two documents are available from the PCDMN:
• An introduction to cereal rust risk and wind trajectories from the USA.
• WIND TRAJECTORY AND CEREAL RUST RISK REPORT for June 3, 2019
Summary of wind trajectory and cereal rust risk assessment and the need for in-crop scouting in the Prairie region, May 28 – June 3, 2019:
1. Pacific Northwest – Currently there is limited stripe rust development in the PNW, a low-moderate number of recent wind trajectories from the PNW, cool and relatively dry Prairie weather conditions, and generally early stages of Prairie crop development, especially in spring cereals. Thus, as of June 3, 2019, the risk of stripe rust appearance from the PNW is limited and scouting for this disease is not urgent.
2. Texas-Oklahoma corridor – In general, crops are advancing towards maturity and thus will become less of a source of rust inoculum. There have been no recent wind trajectories from this area, cool and relatively dry Prairie weather conditions, and generally early stages of Prairie spring crop development. Thus, as of June 3, 2019, the risk of leaf and stripe rust appearance from the Texas-Oklahoma corridor is low and scouting for these diseases is not urgent.
3. Kansas-Nebraska corridor – Although leaf and stripe rust development continues in Kansas with a recent report of stripe rust in Nebraska, it is at low-moderate levels, although there have been reports of elevated levels in regions of Kansas. There have been no recent wind trajectories from this area, cool and relatively dry Prairie weather conditions, and generally early stages of Prairie crop development. Thus, as of June 3, 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.
4. 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 commercial fields of winter wheat in the prairie region.
