Wheat cultivars with very early maturities appropriate for late sowings in low-rainfall (
Very early-maturing genotypes reached anthesis up to 24 days (328 degree-days) earlier than the current cultivars, produced less leaves, had similar yields and dry matter, and maintained high water use efficiencies. On average across seasons and locations the very early-maturing genotypes (W87-022-511, W87-114-549, W87-410-509) yielded more than the later maturing cultivars Gamenya and Spear (190 v. 160 g/m(2)) but they were similar to the early-maturing commercial cultivars Kulin and Wilgoyne (191 g/m(2)). Very early-maturing genotypes generally had a higher han;est index and produced fewer spikelets, but heavier and more grains, than Kulin and Wilgoyne.
There were only small differences in total water use between very early-maturing genotypes and commercial cultivars; however, very early-maturing genotypes used less water in the pre-anthesis period and more water in the post-anthesis period than the later maturing genotypes, and hence, experienced less water deficit during the grain-filling period. This study indicates that there is a role for very early-maturing genotypes in low-rainfall short-season environments, when the first autumn rains arrive late (after 1 June).