Cereal growth staging scales attempt to objectively measure the growth of
cereal
A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize ( Corn). Edible grains from other plant families, ...
s.
BBCH-scale (cereals)
In
agronomy
Agronomy is the science and technology of producing and using plants by agriculture for food, fuel, fiber, chemicals, recreation, or land conservation. Agronomy has come to include research of plant genetics, plant physiology, meteorology, and ...
, the BBCH-scale for cereals describes the
phenological
Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors (such as elevation).
Examples include the date of emergence of leave ...
development of
cereal
A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize ( Corn). Edible grains from other plant families, ...
s using the
BBCH-scale.
The phenological growth stages and BBCH-identification keys of cereals are:
*
1 A leaf is unfolded when its ligule is visible or the tip of the next leaf is visible
*
2 Tillering or stem elongation may occur earlier than stage 13; in this case continue
with stages 21
*
3 If stem elongation begins before the end of tillering continue with stage 30
Feekes scale
The Feekes scale is a system to identify the growth and development of
cereal crops introduced by the Dutch
agronomists
An agriculturist, agriculturalist, agrologist, or agronomist (abbreviated as agr.) is a professional in the science, practice, and management of agriculture and agribusiness. It is a regulated profession in Canada, India, the Philippines, the Uni ...
Willem Feekes (1907-1979) in 1941.
This scale is more widely used in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
than other similar and more descriptive
scales such as the
Zadoks scale or the
BBCH scale. Like other scales of crop development, the Feekes scale is useful in planning management strategies that incorporate plant growth information for the use of
pesticides
Pesticides are substances that are used to pest control, control pest (organism), pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for a ...
and
fertilizers
A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrition, plant nutrients. Fertilizers may be distinct from Liming (soil), liming materials or other non- ...
to avoid damaging the crop and/or maximize
crop yield
In agriculture, the yield is a measurement of the amount of a crop grown, or product such as wool, meat or milk produced, per unit area of land. The seed ratio is another way of calculating yields.
Innovations, such as the use of fertilizer, the ...
.
Zadoks scale
The Zadoks scale is a
cereal
A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize ( Corn). Edible grains from other plant families, ...
development scale proposed by the Dutch
phytopathologist Jan Zadoks that is widely used in cereal research and agriculture.
Knowing the stages of development of a crop is critical in many management decisions that growers make. They are represented on a scale from 10 to 92. For example, in some countries,
nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...
and
herbicide
Herbicides (, ), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page f ...
applications must be completed during the
tiller
A tiller or till is a lever used to steer a vehicle. The mechanism is primarily used in watercraft, where it is attached to an outboard motor, rudder post, rudder post or stock to provide leverage in the form of torque for the helmsman to turn ...
ing stage. In
France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
, the recommendation for the first nitrogen application on wheat is 6 weeks before Z30, with the second application on Z30.
Wheat
Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...
growth regulators are typically applied at Z30. 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). The crop is also more sensitive to heat or frost at some stages than others (for example, during the meiosis stage the crop is very sensitive to low temperature). Knowing the growth stage of the crop when checking for problems is essential for deciding which control measures should be followed.
Examples of typical stages
* during tillering
**Z10: one leaf
**Z21: tillering begins
* during stem extension
** Z30: ear is one centimeter long in wheat
** Z31: first node visible
** Z32: second node visible
** Z37: flag leaf
* during heading
**Z55: the head is 1/2 emerged.
* during ripening
**Z92: grains are ripe
References
*
*
*{{cite journal
, last = Witzenberger
, first = A.
, author2=H. Hack , author3=T. van den Boom
, title = Erläuterungen zum BBCH-Dezimal-Code für die Entwicklungsstadien des Getreides - mit Abbildungen
, journal = Gesunde Pflanzen
, volume = 41
, pages = 384–388
, date = 1989
Further reading
* J.C. Zadoks, T.T. Chang, C.F. Konzak, "A Decimal Code for the Growth Stages of Cereals", ''Weed Research'' 1974 14:415-421.
External links
Citation Classic of 1985
Agronomy
BBCH-scale
Cereals