Dual-purpose use affects phenology of triticale

Treating cereals as a dual-purpose crop (grazing and grain production) can modify the timing of anthesis, but which among the main determinants of the timing of anthesis - namely leaf number, the phyllochron and the length of the flag leaf emergence to anthesis interval - are affected is unclear. Eight field experiments conducted in triticale, designed to vary both sowing date (October through January), growth habit (vernalization requiring vs non-requiring) and to simulate grazing by clipping at the terminal spikelet stage (TS), were performed to monitor plant development. Clipping delayed anthesis by 2-7 days in four cultivar/environment combinations. The slower rate of leaf emergence after clipping delayed the appearance of the flag leaf ligule (FLA). When a delayed FLA was not accompanied by a proportional reduction in the duration of the FLA-anthesis interval, anthesis occurred later. The impact of an increase in the phyllochron can be expected to be wider than just a delay to anthesis. A higher phyllochron can also result in a slower recovery of leaf area, with a knock-on effect on the duration of the most critical period for grain number determination.