Growth, yield and composition of four winter cereals. 1. Biomass, grain yield and yield formation.

A field experiment with 3 cultivars of each of 4 winter cereals (wheat, rye, triticale and barley), sown at about 320 plants/msuperscript 2, was conducted on a fertile clay soil in the central Netherlands. The N fertilizer was split-dressed: 120 kg/ha in total for wheat and triticale, and 60 kg/ha for rye and barley. The fewest shoots/msuperscript 2 were found in triticale (828/msuperscript 2), and the most in barley (1477/msuperscript 2). The average decrease in number of shoots during shoot/ear development was 51% in wheat, 54% in rye, 49% in triticale and 67% in barley. The rate of crop development was largest in rye and barley; they flowered and matured earlier than wheat and triticale. Rye was the first to attain a closed canopy (LAI >3), and had the lowest maximum LAI and shortest leaf area duration. Wheat and triticale stayed green longest. Average specific leaf weight was 4.3 mg/cmsuperscript 2 in wheat and triticale, and 3.7 mg/cmsuperscript 2 in rye and barley. The growth rate of the grains at the linear stage was fastest in barley (1.89 mg grain-1 d-1) and slowest in rye (0.89 mg grain-1 d-1). Total aboveground DM production was 18 790 kg/ha in wheat, 15 230 kg/ha in rye, 18 300 kg/ha in triticale and 12 460 kg/ha in barley. Grain yields (t/ha) were 8.74 (wheat), 6.64 (rye), 8.20 (triticale) and 6.62 (barley). Cultivar differences in grain yield and in yield components were mostly smaller in wheat and rye than in triticale and barley. The harvest index was highest in barley (53.3%) and lowest in rye (43.7%); in some plant species there were marked differences between cultivars, but in others there were not.