Agronomic and growth characteristics of spring spelt compared to common wheat
Spelt wheat (Triticum aestivum L. emend. Thell) (spelta group) is an ancient, hulled, specialty wheat which is presently grown on a limited scale as a fall-sown crop in Western Europe. Little is known about the agronomics and growth characteristics of spring spelt, a potential specialty wheat for western Canada. The main objectives of this study were to compare the yield potential and growth characteristics of spring spelt wheat to that of common spring wheat (Triticum aestivum L. emend. Thell) in central Saskatchewan, using growth analysis; to investigate the response of spring spelt to seeding date; and to determine the effect of the hulls of spelt on seedling emergence and establishment under adverse temperature and moisture conditions. The seeding rate and growth analysis experiment was conducted in the field using two spring spelt cultivars (CDC Bavaria and PGR8801) and a common wheat cultivar (Katepwa) at four seeding rates ranging from 150 to 450 seeds/m 2 at Saskatoon, Saskatchewan, in 1995 and 1996. The response of spring spelt and common wheat to seeding date was measured from late April to early June under field conditions over two years. The role of spelt hulls on seed germination, seedling emergence and crop establishment was studied under field conditions using an early (late April) and a late (early June) date of seeding over two years. Seed germination, seedling establishment and seed water uptake were studied under controlled environment conditions at water potentials ranging from 0 to -1.8 MPa, at temperatures of 9, 16 and 23°C. The field studies indicated that spring spelt can produce grain yield comparable to common wheat. The same seeding rate as common wheat (150 to 250 seeds/m2) can be used for spring spelt wheat in central Saskatchewan. Spring spelt has a higher leaf area index (LAI), leaf area duration (LAD) and crop growth rate (CGR) than common wheat, giving rise to 24 per cent higher biological yield for spring spelt compared to that of common wheat. Optimal seeding date for spring spelt is late April to early May; with later seeding spring spelt's grain yield tends to decrease. Seedling establishment for spring spelt is lower and less stable than common wheat, though this variation in seedling plant density does not influence the final grain yield. Controlled environment studies indicated that the hull of spring spelt wheat acts as an obstacle to water uptake, leading to an approximate 25 per cent slower water uptake rate compared to naked seeds. The hull has negative impact on seed germination and seedling emergence. The negative impact of the hull on seed water uptake, seed germination and seedling emergence increases under drought conditions. Thus, only under sufficiently wet soil conditions may using hulled seed as the propagule lead to comparable establishment of spring spelt relative to common wheat. In conclusion, spring spelt can be grown successfully in central Saskatchewan, producing a comparable grain yield to common wheat provided it is seeded before mid-May.