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

Abstract

Field trials were conducted for 3 yr (2002/2003 to 2004/2005) at three locations in southern Alberta to determine the impact of seeding rate and opener type on plant stand and grain yield of winter wheat (Triticum aestivum L.) and winter triticale (× Triticosecale Wittmack). Responses were determined for an optimum date of seeding in early to mid-September and for a late seeding in early to mid-October. Conditions were generally favourable for crop establishment, winter survival and growth, and average site yields ranged from 4.5 to 8.9 Mg ha-1. The disc opener increased spring plant density by 12.5% compared with the hoe opener, but did not affect grain yield. Spring plant density was 23% lower for winter triticale than winter wheat and 20% lower for October-seeded cereals than September-seeded cereals. Late seeding reduced grain yields of winter wheat and winter triticale by an average of 18 and 11%, respectively. Increases in target seeding rates from 150 to 350 plants m-2 (approximately 70 to 160 kg ha-1) did not affect grain yield and quality of September-seeded cereals, but increased grain yield of late-seeded crops by an average of 5 kg per kg increase in seeding rate. High seeding rates did not fully compensate for yield losses caused by late seeding. Key words: Triticum aestivum, × Triticosecale, plant stand density, yield