Determining Optimum Target Plant Stands for Spring Cereal Crops in Manitoba
Anne Kirk, Manitoba Agriculture; Manitoba Agriculture Diversification Centres
1) Determine if target plant stand recommendations should be adjusted for spring wheat, oat, and barley
2) Determine if optimum plant stands differ for individual varieties
3) Assist producers with determining target plant stand and seeding rate for newer spring cereal varieties
This study is a continuation of a research project that took place at Arborg, Carberry, Melita, and Roblin in 2017 and 2018. The oat and barley sites in 2017 and 2018 showed similar yields across a range of plant stands, indicating that the current recommended target plant populations for barley and oat are sufficient. At the wheat sites in 2017 and 2018 there was a general trend of higher yields with increased plant stands, but no significant difference in yields between target plant stands of 21 to 39 plants/ft2 at four of the five sites.
The 2021 results are similar, in that there were no significant yield differences across the range of plant densities at most sites. There was a general trend of higher yields with higher plant stands at the wheat, barley, and one of the oat sites, although the data indicates that these trends should be taken with caution. There were no significant difference in yields between target plant stands of 21 to 39 plants/ft2 at nine out of the 10 sites. At all sites, both varieties tested responded similarly to each target plant stand, indicating that similar seeding rate recommendations could be made for both varieties of each crop type studied.
Yield of spring cereals is impacted by many agronomic practices, but starts with variety selection, seeding date, target plant stand, and the seeding rate needed to achieve those plant stands. Optimum plant population is determined by factors including crop management practices and growing conditions. Manitoba Agriculture currently recommends target plant stands of 23-28 plants/ft2 for spring wheat, 18-23 plants/ft2 for oat, and 22-25 plants/ft2 for barley. With the introduction of semi-dwarf and higher yielding cultivars, target plant stands may need to be adjusted to maximize profitability. Pervious research has shown that optimum plant populations can differ by both crop type and variety. In a North Dakota study, Mehring et al. (2016) found that optimum seeding rates for spring wheat ranged from 14 to 46 plants/ft2 depending on the characteristics of the variety.