Plant spatial arrangement to maximize spring wheat (Triticum aestivum L.) yield in Manitoba in dry conditions

Thumbnail Image
Clemis, Samantha
Journal Title
Journal ISSN
Volume Title
Spring wheat (Triticum aestivum L.) currently accounts for the second-largest area of seeded acres in Manitoba. However, information is limited on the optimal plant spatial arrangement to maximize seed yield for modern spring wheat cultivars grown in Manitoba, particularly following a soybean crop. The objectives of this research project were to determine row spacing and seeding density combinations in two modern spring wheat cultivars that maximize seed yield and if the preceding crop (canola or soybean) affects this relationship. Field experiments were conducted at Carman, Howden, and Portage la Prairie, Manitoba, in 2019 and 2020. AAC Brandon and Cardale spring wheat cultivars were subjected to three row spacings (9.5, 19, and 38 cm), four seeding densities (200, 300, 400, and 500 target plants m-2), and two stubble types (canola and soybean). Below-average precipitation was received throughout the growing season at all site-years. AAC Brandon and Cardale seed yield was significantly greater when seeded at the more narrow (9.5 cm or 19 cm) row spacings compared with the wider (38 cm) row spacing. Narrow row spacing treatments resulted in increased and more rapid ground cover, suggesting improved water, sunlight, and nutrient utilization by spring wheat plants. Increasing AAC Brandon and Cardale plant density generally did not influence seed yield. Cardale spring wheat was more responsive to changes in row spacing and seeding density treatments compared with AAC Brandon spring wheat. Collectively, this research indicates that in dry growing conditions, spring wheat growers in Manitoba have the opportunity to increase seed yields by seeding spring wheat at narrower row spacings following a canola or soybean crop. However, more research on producer constraints may lead to increased narrow row adoption by growers. Further research is also necessary to investigate the yield-density relationship during growing seasons that receive more average or above-average precipitation.
yield, spring wheat, plant spatial arrangement, dry conditions, row spacing, plant density, stubble type