Influence of no-till furrow opener and seed treatment on ultra-early wheat seeding systems

Abstract

Ultra-early planting is an alternative practice that involves planting based on soil temperature, initiated once the trigger temperature of >0°C is observed, regardless of calendar date. Our previous research concluded that spring wheat (Triticum aestivum L.) grain yields are maintained or improved with enhanced yield stability when adopting this practice. However, a knowledge gap remains around the influence of furrow opener configuration and seed treatments to mitigate abiotic stressors related to cold soil and ambient temperatures. Thus, a 5-year experiment was conducted in Lethbridge, AB, to examine the effects of planting dates triggered by soil temperatures of 0°C, 2.5°C, 5°C, 7.5°C, and 10°C; seed treatment (tebuconazole, prothioconazole, metalaxyl, and imidacloprid vs. untreated); and furrow opener (knife vs. disc) on ultra-early planted spring wheat. Optimal grain yield was achieved when wheat was planted at a soil temperature of 0°C, irrespective of seed treatment and furrow opener type. A significant yield reduction was observed when wheat was planted at a soil temperature of 10°C. Wheat planted at soil temperatures of ≤7.5°C with a disc opener often resulted in high and stable yields, regardless of seed treatment. Grain protein concentration responses to soil temperature trigger were less consistent, but wheat planted at 10°C accumulated low and unstable concentrations. Seed treatment delayed emergence, flowering, and maturity; reduced head density; and ultimately lowered grain yield. Overall, spring wheat grain yield and protein concentration were optimized when planted at soil temperatures of ≥0 and ≤7.5°C using a disc opener, regardless of seed treatment adoption.