Best Management Practices for Implementing Ultra-Early Spring Wheat (Triticum aestivum L.) Growing Systems on the Northern Great Plains
Creators: Collier, Graham R. S.
Publisher: name: University of Alberta Library
Year: 2023

<p>Ultra-early planting of spring wheat (Triticum aestivum L.) between soil temperatures of 0°C and 7.5°C on the northern Great Plains allows the exploitation of longer growing seasons and the avoidance of the onset of extreme heat later in the season during sensitive physiological growth stages, including flowering and grain filling. Recent studies in western Canada assessed ultra-early planting, and the management practices and wheat cultivars required to successfully implement ultra-early wheat planting on the northern Great Plains. Planting wheat between soil temperatures of 2°C and 6°C optimized grain yield and grain yield stability in western Canada. Planting between 0°C and 7.5°C always resulted in greater grain yield and grain yield stability than delaying planting to a conventional planting time at 10°C soil temperature or higher. Current commercial Canadian hexaploid spring wheat varieties exhibited improved grain yield and grain yield stability when planted ultra-early. No differential in grain yield stability was present between specially-developed cold tolerant wheat lines and current commercial Canadian hexaploid spring wheats. When assessed at ultra-early and conventional planting times, no individual cultivar or group of cultivars representing a Canadian wheat market class, had greater grain yield or grain yield stability when planting was delayed to the conventional time. The grain yield and grain yield stability of ultra-early planted wheat can be improved with the implementation of optimized management practices in an ultra-early wheat growing system. An optimal sowing density of 400 seeds m-2 increased grain yield as well as grain yield stability for ultra-early planted wheat. Shallow sowing depths (2.5 cm) did not affect grain yield, but when assessed in combination with optimal sowing rates, improved grain yield stability of ultra-early planted wheat. Spring weed management using fall-applied residual herbicides reduced early season weed pressure, increased grain yield in some locations, and did not negatively affect grain yield stability of ultra-early planted wheat. An optimized growing system for ultra-early planted wheat on the northern Great Plains includes a regionally adapted, competitive, Canadian hexaploid spring wheat cultivar, planted at 2.5 cm depth when soil temperatures are between 2°C and 6°C, at an optimal sowing density of not less than 400 viable seeds m-2. Fall-applied residual herbicides can be safely used in the growing system to manage spring weed pressure if required. Ultra-early wheat growing systems can be immediately implemented to increase grain yield and grain yield stability on the northern Great Plains. Producers adopting ultra-early wheat growing systems will realize additional grain yield and grain yield stability benefits relative to conventional planting with the increases of daily average temperatures and atmospheric CO2 concentrations predicted to occur over the next thirty years.  </p>