COMPARISON OF GRAIN-YIELD OF UNIBLENDS AND BIBLENDS OF 10 SPRING BARLEY CULTIVARS

Pure strands (uniblends) of 10 cultivars of spring barley and the 45 possible 50:50 mixtures (biblends) were evaluated for 3 yr in 4-replicate randomized blocks. In addition to plot grain yield, data were collected on grain weight, shoot weight and harvest index from 20 plants (10 in 1977) sampled from each uniblend and from 10 plants of each of the components of each of the biblends. Single plant sampling was carried out in only 2 replicates in each year. Cultivar identification in the biblend samples was facilitated by evaluation of spike and seed characteristics of each plant. Analyses of whole plot yield and of single plant data indicated that there were no significant differences between average performances in uniblends and biblends. Absence of significant interaction implied that relative cultivar performance in uniblends and biblends was the same. Intergenotypic competition among relatively well adapted genotypes should not be of serious consequence in barley breeding programs.