Abstract
Field experiments were conducted to determine the reasons, on the basis of growth analysis, for the high-yielding new winter triticale cultivars bred in Poland in comparison with those of Japanese wheat cultivars, and Polish, Korean and German rye cultivars from 1995 to 1999. The difference in grain yield between triticale and wheat was due to a difference in crop growth rate (CGR) from the regrowing stage after winter to the flag leaf stage. This difference in CGR was attributed to the differences in mean leaf area index (MLAI) and net assimilation rate (NAR). On the other hand, the difference in grain yield between triticale and rye was due to the difference in harvest index, which resulted from the difference in ear growth rate (EGR) during the grain filling period. The EGR was significantly related to MLAI and the dry matter partitioning ratio to ear during the grain filling period. The differences among the three crops were greater than cultivars differences in each crop. These results indicated that the high yield of the new winter triticale cultivars was derived from a combination of the high vigor at the early vegetative growth stage in rye and the high efficiency of grain filling in wheat.
