Cereal growth staging scales

The phenological growth stages and BBCH-identification keys of cereals are: still green with stages 21 The Feekes scale is a system to identify the growth and development of cereal crops introduced by the Dutch agronomists Willem Feekes (1907-1979) in 1941.

Knowing the stages of development of a crop is critical in many management decisions that growers make.

For example, in some countries, nitrogen and herbicide applications must be completed during the tillering stage.

Disease control is most critical in the stem extension and heading stage (Z31, Z32, Z35), in particular as soon as the flag leaf is out (Z37).

Knowing the growth stage of the crop when checking for problems is essential for deciding which control measures should be followed.

Critical stages according to BBCH (Lancashire et al., 1991) and their deviations from the Zadok's scale (in brackets). The spacing between the stages follows calendar time for the temperate climate of Switzerland (sowing in November, harvest mid-July)