Growth & Development
The growth and development of the small grains (wheat, triticale, barley, and oat) follow very similar patterns.
Plant development is divided into several stages: Germination and Early Seedling Growth, Tillering and Vegetative Growth, Elongation and Heading, Fowering, and Kernel Development.
Numerical scales have been devised for quantifying the growth stages of small grains. Those most commonly used are the Zadoks, Feekes, and Haun growth scales.
The Feekes scale (1 to 11.4) numerically identifies stages from emergence through ripening.
The Haun scale deals mainly with the pattern of leaf production, in which the length of each emerging leaf is expressed as a fraction of the preceding leaf.
For more information on these scales, see Simmons, Oelke, and Anderson 1995.