The pattern of grain set within ears of wheat

Abstract

Experiments involving sterilization, or emasculation and delayed pollination, of the basal florets of central spikelets of wheat ears were carried out in the field, in England and maxico, and in the Australian phytotron, to investigate how grain set in those florets influences that elsewhere in the ear. In intact ears of three cultivars of winter wheat, Cappelle-Desprez, Mari Ranger, and Maris Nimrod, only about half of the florets which differentiated in thecentral spikelets developed green anthers, even fewer reached anthesis, and still fewer set grains. Florets reaching anthesis within 2 days of the earliest florets setgrain regardless of their position in the ear, but in later florets those towards the base of the ear were more likely to set grain. In field experiments with these varieties, and also with the spring cultivar Triple Dirk, sterilization of basal florets of up to eight central spikelets in each ear resulted in more grains being set in the distal florets of those spikelets. Experiments with Triple Dirk in the phytotron, in which the basal florets were emasculated before anthesis but pollinated at various times thereafter, showed that most ovaries remained viable up to 5 days after anthesis, and that both emasculation and delayed pollination increased grain set above that in intact ears. © 1972 CSIRO.