Agriculture Reference
In-Depth Information
pling and often magnifi cation. The external
developmental stages have traditionally focused
on developmental events that can be observed
fairly readily without magnifi cation or destructive
sampling.
have been developed to describe wheat phenol-
ogy, with many similarities between them (e.g.,
Frank et al., 1997). Discussions and comparisons
among some scales are provided by Bauer et al.
(1983), Landes and Porter (1989), and Harrell et
al. (1993, 1998).
Of the many growth staging scales, four cur-
rently have the greatest usage: Feekes (Large
1954), Zadoks et al. (1974), Haun (1973), and the
BBCH Scale (Lancaster et al., 1991). All scales
consider some basic developmental events such as
germination and emergence, leaf production, til-
lering, internode elongation, fl owering or anthe-
sis, stages of grain ripening, and physiological
maturity (Fig. 2.1), with particular scales empha-
sizing different processes.
Phenology
Human cultures have long recognized that plants
go through fairly consistent stages of develop-
ment each year. Common terminology has often
referred to these stages as growth stages, but
developmental stages is the more appealing term
as often little “growth” is involved in the devel-
opmental event (e.g., anthesis and physiological
maturity). Many so-called growth staging scales
Single Ridge
Double Ridge
Terminal Spikelet
Anthesis (spikelet)
apical
dome
spikelet
initial
leaf
initial
leaf
primordium
PROFILE VIEW
FACE VIEW
STEM EXTENSION
RIPENING
HEADING
STAGE
11
STAGE
10.5
flowering
(wheat)
STAGE
10.1
STAGE
10
STAGE
9
in 'boot'
ligule of
last leaf
just
visible
STAGE
8
TILLERING
last leaf
just
visible
STAGE
7
STAGE
6
second
node
visible
STAGE
5
first
node
of stem
visible
STAGE
4
leaf
sheaths
strongly
erected
STAGE
3
STAGE
2
leaf
sheaths
lengthen
STAGE
1
tillers
formed
tillering
begins
one
shoot
Fig. 2.1
The Feekes growth stage scale (Large 1954) correlated with the approximate timing of certain shoot apex develop-
mental stages. See Table 2.1 for descriptions of developmental stages. (Adapted from McMaster 2005.)
