Comparison of grain growth and yield of a semi-dwarf wheat and a standard height wheat grown in the Victorian Mallee

Abstract

Ear development, grain growth and yield of a semi-dwarf wheat, Condor, and a standard height wheat, Halberd, were compared in a field experiment over two seasons and in a glasshouse experiment at Walpeup in the Victorian Mallee. A sequence of sowing times was used with the field-grown wheat to obtain variation in flowering time and conditions during ear development and grain growth. Condor developed more spikelets, which resulted in more grains per ear. This difference in spikelet number was associated with a longer duration of spikelet initiation. Grain growth per ear for the two cultivars was identical with the exception of two early sowings of Condor. The grain weight of Condor was always lower than that of Halberd from a similar sowing. Different effects were obtained in the cultivars from pre-anthesis drought in a glasshouse experiment, with the semi-dwarf wheat having better floret survival. Pre-anthesis drought resulted in a 21% reduction in grain number with Halberd, which, with adequate water after anthesis, made a 7% compensatory increase in grain weight. A similar pre-anthesis stress did not much reduce grain number with Condor, but this treatment did reduce (2%) grain weight, particularly at the spike apex and distal florets.