A comparison of semi-dwarf and standard height wheat varieties at two levels of water supply

Abstract

Two semi-dwarf wheats, Mexico 120 and a late-flowering selection from this variety, were compared with two standard-height Australian varieties, Heron and Sunset. Each variety was grown with and without irrigation and lodging was controlled with artificial supports. Under natural rainfall, Mexico 120 yielded more than the standard-height varieties but the late-flowering selection yielded least of all. With irrigation, however, both semi-dwarf varieties showed a yield advantage. Features of the semi-dwarf wheats were shorter culms and longer ears, a larger proportion of car weight at anthesis, more grains set and a greater ratio of grain yield to post-anthesis leaf area. The significance of these and other factors is discussed in relation to wheat improvement in the Australian environment.