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.
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 17, 2019
Summary of wind trajectory and cereal rust risk assessment and the need for in-crop scouting in the Prairie region, June 11-17, 2019:
1. Pacific Northwest – Currently there is limited stripe rust development in the PNW, a low number of recent wind trajectories from the PNW, and relatively dry Prairie weather conditions, while winter wheat is progressing into heading and beyond, and spring wheat is moving into the stem elongation stage. Thus, as of June 17, 2019, the risk of stripe rust appearance from the PNW is relatively low and scouting for this disease is not urgent.
2. Texas-Oklahoma corridor – In general, crops are advancing towards maturity, while in many areas of Texas harvesting has been completed, and thus winter wheat crops in these areas will become less of a source of rust inoculum. There has been a limited number of recent wind trajectories from this area, relatively dry Prairie weather conditions, while winter wheat is progressing into heading and beyond, and spring wheat is moving into the stem elongation stage. Thus, as of June 17, 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 – Leaf and stripe rust development in winter wheat continues in Kansas, although the winter crop is starting to turn colour in many regions. Although rusts have only been recently reported in Nebraska, levels are on the rise, and thus over the next few weeks this region could act as a significant source of rust inoculum for the Prairie region. From June 11-17, 2019 there has been a low number of wind trajectories from this area. In general, weather conditions have been relatively dry across the Prairies, while winter wheat is progressing into heading and beyond, and spring wheat is moving into the stem elongation stage. Thus, as of June 17, 2019, the risk of leaf and stripe rust appearance from the Kansas-Nebraska corridor is relatively low and scouting for these diseases is not urgent; however, further development of rust Nebraska 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 this spring. Scouting is especially critical where the variety being grown is susceptible to stripe rust. Currently, there are no reports of stripe rust in commercial fields of winter or spring wheat across the Prairie region.
