Seed Rate and Row Spacing of No‐Till Winter Wheat

Abstract

A snow management system, which utilizes no‐till seeding into standing stubble immediately after harvest of the previous crop, has permitted the expansion of winter wheat (Triticum aestivum L.) production in western Canada. The effect of seed rate and row spacing on grain yield and yield components of no‐till winter wheat were evaluated in 21 trials conducted in Saskatchewan from 1986 to 1988. Two winter wheat cultivars were evaluated in eight of the trials. The relationship between grain yield (Y) and seed rate was best described by a modified inverse polynomial: Y = uSR(1‐SR/566)/(SR + u/104) where u represents the upper limit of yield when seed rate is not limiting. This curve accounted for 98% of the observed variation in grain yield. Optimum seed rate varied from 58 kg ha−1 at a very dry trial to 148 kg ha−1 in a trial with more favorable growing conditions. Grain yield increased as row spacing decreased and the effect of row spacing on pain yield was increased under more favorable growing conditions. Increased seed rate and decreased row spacing interacted positively to increase grain yield so optimum seed rate increased as row spacing decreased. Increased spikes per square meter was responsible for the increase in grain yield associated with high seed rate and narrow row spacing. In contrast, kernel weights were slightly higher with low seed rate and kernels per spike were higher with low seed rate and wide row spacing. Optimum seed rate was higher for the cultivar ‘Norstar’ than for ‘Norwin’ due to higher yield potential of Norstar under the conditions experienced in this study.

Efficacy of high seeding rates to increase grain yield of winter wheat and winter triticale in southern Alberta

“…The results from this study are consistent with the relationship observed between plant density and grain yield in North Dakota, where maximum grain yields were achieved at plant densities ≥80 m -2 . The seeding rate required for maximum yield in this study was lower than that estimated for winter wheat in Saskatchewan (approximately 160 kg ha -1 under high-yielding conditions) (Tompkins et al 1991) or Montana (140 plants m -2 ) (Holen et al 2001). Maximum cereal yields may be achieved over a wide range of seeding rates due to compensation of yield components (tillers per plant, number of kernels per spike, kernel size) (Tompkins et al 1991;Jedel and Salmon 1993).…”

“…1b). The non-responsiveness of September-seeded treatments to seeding rate indicates that the minimum seeding rate required for maximum yield was less than or equal to the lowest seeding rates included in this study and that possible reductions in grain yield due to excessive seeding rates (Tompkins et al 1991) did not occur over the range of seeding rates and environmental conditions present in this study. The results from this study are consistent with the relationship observed between plant density and grain yield in North Dakota, where maximum grain yields were achieved at plant densities ≥80 m -2 .…”

“…Maximum grain yield of hard red winter wheat was achieved with approximately 80 plants m -2 in North Dakota (Black and Bauer 1990) and 140 plants m -2 in Montana (Holen et al 2001). Under a wide range of moisture conditions in Saskatchewan, Tompkins et al (1991) found that the optimum seeding rate for hard red winter wheat ranged from 58 kg ha -1 under dry conditions to 148 kg ha -1 under favourable growing conditions. The optimum seeding rate for winter wheat was between 100 and 130 kg ha -1 for row spacings ranging from 10 to 30 cm at Indian Head, Saskatchewan (Lafond and Gan 1999).…”

“…Favourable growing conditions increase the benefit of high seeding rates (Tompkins et al 1991), but may reduce the response to seeding date or opener type due to increased opportunity for compensation of poor crop establishment in the fall with increased growth in the spring.…”

“…Maximum grain yield of hard red winter wheat was achieved with approximately 80 plants m -2 in North Dakota (Black and Bauer 1990) and 140 plants m -2 in Montana (Holen et al 2001). Under a wide range of moisture conditions in Saskatchewan, Tompkins et al (1991) …”