Agronomic response to seeding rate of two- and six-rowed barley cultivars in central Alberta

Abstract

Little information is available on the response of two-rowed barley (Hordeum vulgare L.) cultivars to seeding rate in central Alberta. The objective of this research was to compare the effects of seeding rates of 129–344 seeds m−2 (50–140 kg ha−1) on the agronomic response of two- and six-rowed barley grown in central Alberta. Grain yields of 5.8–6.1 t ha−1 were not affected by seeding rates in 1990 and 1991 at Lacombe. As seeding rates increased in 1992, grain yields at Lacombe increased from 6.4 to 7.8 t ha−1; at Olds, from 3.5 to 4.0 t ha−1; and at Botha for the 129 seeds m−2 treatment, yields were only 5.5 t ha−1, compared with 5.8 to 6.0 t ha−1 for the other treatments. Effects of seeding rate on test and kernel weights varied between location–years. Tiller numbers m−2 were found to increase at higher seeding rates for the two-rowed cultivars, Abee and Harrington, while for the six-rowed cultivars, Noble and Virden, these numbers remained constant. Node numbers spike−1 decreased with higher seeding rates for both two- and six-rowed cultivars. There was little effect of seeding rate on kernel number spike−1 for the two-rowed cultivars, while for the six-rowed cultivars this number decreased. Although the two- and six-rowed cultivars differed in their partitioning of yield and the effects of seeding rates on these components, their yield responses to seeding rate did not differ. Recommended seeding rates for barley in central Alberta should be above 129 seeds m−2 (50 kg ha−1). To maintain high kernel and test weights, seeding rates for barley grown in central Alberta for malt quality should range from 172 to 258 seeds m−2. When conditions warrant accelerated development, seeding rates of 300 or more seeds m−2 should be used. Key words:Hordeum vulgare, management, yield components