Effect of spring cereal seeding rate on its yield potential
Anne Kirk, Manitoba Agriculture
Manitoba Agriculture Diversification centers
- Determine if target plant stand recommendations should be adjusted for spring wheat, oats, and barley.
- Determine if optimum plant stands differ for individual varieties.
- Assist producers with determining target plant stand and seeding rate for newer spring cereal varieties.
Stand establishment increased as seeding rate increased at most site years. There was no significant difference in plant stand between seeding rate treatments for wheat at Roblin, results will not be shown for this site as a range of plant populations were not established. At many locations plant stands were lower than the target. The exception was Arborg where plant stands ranged from 18-57, 12-47, and 25-35 plants /ft2 in the barley, oats, and wheat plots, respectively.
Cereals can compensate for lower plant populations by increasing tillering. Research in which spring wheat plants were given ample room found that stems per plant ranged from 19 to 44 depending on the variety. While cereal cultivars differs in their abilities to tiller, there was no difference in heads per plant between cultivars at the majority of sites. The actual number of spikes or panicles present at maturity depends on the number of tillers produced and the number that survive to maturity. The effect of drought stress on yield components depends on the timing of drought stress, and early season drought stress reduces yield potential through tiller death (Duggan et al. 2000). This is evident in the results from the Arborg location, where heads per plant were low across all crop types and treatments.
Heads per plant decreased as seeding rate increased, which demonstrates the ability of cereal crops to compensate for reduced plant populations by increasing tillering. There was no significant difference in heads per plant at target plant populations ranging from 21-39 plants /ft2 at five out of the eight sites where there were significant differences in heads per plant.
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 oats, 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.
Entire findings are available by downloading the report PDF.