Wheat Streak Mosaic Management
Published
7/29/2025
1. Wheat streak mosaic management: Pay attention to wheat-free windows (Agronomy eUpdate, July 10, 2025)
This first article introduces the concept of regionally defined 30-day “wheat-free windows” just before the optimal planting date for winter wheat in each Kansas growing zone. These windows allow volunteer wheat and other green hosts—including rye or triticale—to be completely terminated well ahead of planting, breaking the green bridge that sustains wheat curl mites and viral pathogens like WSMV. The piece also compares herbicide options, noting that fast-acting products like paraquat or Sharpen mixtures reduce mite survival better than glyphosate. Coordinated, community-wide control of volunteers is emphasized as essential.
2. Wheat streak mosaic management: The role of other hosts in the landscape (Agronomy eUpdate, July 17, 2025)
This second article highlights how alternative hosts — volunteer wheat, various cereal crops, pasture grasses, and weeds — can sustain wheat curl mite populations and the wheat streak mosaic virus through the summer. Based on risk factors like mite reproduction suitability, host density, and overlap with critical summer periods, volunteer wheat ranks highest, followed by winter cereals planted early. While crops like corn and sorghum pose lower risk, some grassy weeds (e.g. foxtails) may still act as reservoirs. Coordinated elimination of all hosts across the landscape is recommended for effective management.
3. Wheat streak mosaic management: The role of variety resistance (Agronomy eUpdate, ~July 2025)
The third article emphasizes genetic resistance as a critical component of integrated wheat streak mosaic complex management. It distinguishes two types of resistance: virus resistance (e.g., genes wsm1, wsm2, wsm3) and curl mite resistance (e.g., gene cmc4). Many Kansas-adapted varieties like KS Dallas, Guardian, Oakley CL, KS Mako, and KS Bill Snyder carry wsm2, which offers good control of WSMV but not Triticum mosaic virus or High Plains virus. It is also temperature-sensitive, with effectiveness reduced above roughly 70?°F. Varieties with curl mite resistance help by reducing mite buildup, though they remain susceptible to virus infection and are often adapted for western Kansas. It stresses careful timing and variety choice — in addition to volunteers and landscape host control — for robust defense against the virus complex.