Yield, quality and stress tolerance of barley mixtures in central Alberta

Intraspecific mixtures may be a means of enhancing the genetic variability of modern crops while retaining the advantages of yield, quality, and stress tolerance of modern cultivars. Two- and three-way barley (Hordeum vulgare L.) mixtures of the cultivars Abee, Noble, Tukwa and Virden, were studied at Botha, Lacombe and Olds, Alberta, from 1992 to 1994. Treatments consisted of the four cultivars as monocrops and in 6 two-way and 3 three-way mixtures grown at a seeding rate of 250 seeds m(-2). Tukwa as a monocrop had the highest rank and best stability for grain yield of all the treatments. Grain yields of the mixtures usually fell between the yields of the respective monocrops and were often better than the weighted mean yield of the monocrops indicating that many mixtures were more effective at using resources than the monocrops. Of the mixtures, Tukwa:Noble, Tukwa:Abee:Virden and Noble:Virden had the best rankings and stability for grain yield. Test weights, kernel weights, percent thins, lodging, disease incidence and protein content of the mixtures were intermediate to those of the monocrops. Mixtures containing the two-rowed cultivar Abee had higher test weight and protein content than mixtures composed of only six-rowed cultivars. Lodging and disease ratings were lower for the mixtures composed of only six-rowed cultivars than those with Abee. In these intraspecific barley mixtures, Virden was often the most competitive cultivar while Tukwa was the least. Competitive ability was not associated with yield potential, tillering, or row-type.