Northern Prairie Wildlife Research Center
Smooth brome tiller elongation begins in early May in the central Great Plains and Midwest in response to increased day length (Lamp, 1952). Heading begins when inflorescences begin to show about the fourth week in May and this continues for about two weeks. Flowering begins about the second week in June and also lasts about two weeks. Seeds ripen in late July as the panicles turn brown.
In grasses, the amount of stored carbohydrates varies seasonally and is dependent on the growth rate, the stage of plant development, and environmental factors (White, 1973). Smooth brome carbohydrate reserves are low during two stages of development. Teel (1956) describes an annual juvenile or jointing stage of smooth brome tiller development that is characterized by rapid vegetative growth associated with tiller internode elongation and relatively low root carbohydrate storage (Fig. 2). A second carbohydrate low occurs at late panicle emergence when the floral structures develop (Eastin and others, 1964, Paulsen and Smith, 1969).
|Figure 2. Relationship between concentration of total fructose (carbohydrates) in the basal internodes of smooth brome tillers and its various growth stages: tiller emergence (TE), tiller elongation (TL), tiller heading (HE), and tiller flowering (FL).|