The BBCH-scale is used to identify the phenological development stages of plants.^[1] BBCH-scales have been developed for a range of crop species where similar growth stages of each plant are given the same code.

Phenological development stages of plants are used in a number of scientific disciplines (crop physiology, phytopathology, entomology and plant breeding) and in the agriculture industry (risk assessment of pesticides, timing of pesticide application, fertilization, agricultural insurance). The BBCH-scale uses a decimal code system, which is divided into principal and secondary growth stages, and is based on the cereal code system (Zadoks scale) developed by Jan Zadoks.^[2]

The abbreviation BBCH derives from the names of the originally participating stakeholders: "Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie". Allegedly, the abbreviation is said to unofficially represent the four companies that initially sponsored its development; Bayer, BASF, Ciba-Geigy, and Hoechst.^[3]

Basic principles

• The BBCH-scale provides a framework to develop scales for individual crops.
• Similar growth stages of each plant species are given the same BBCH code.
• Each code has a description and important growth stages have additional drawings included.
• The first digit of the scale refers to the principal growth stage.
• The second digit refers to the secondary growth stage which corresponds to an ordinal number or percentage value.
• Post harvest or storage treatment is coded as 99.
• Seed treatment before planting is coded as 00.

Principal growth stages

• 0: Germination, sprouting, bud development
• 1: Leaf development
• 2: Formation of side shoots, tillering
• 3: Stem elongation or rosette growth, shoot development
• 4: Development of harvestable vegetative plant parts, bolting
• 5: Inflorescence emergence, heading
• 6: Flowering
• 7: Development of fruit
• 8: Ripening or maturity of fruit and seed
• 9: Senescence, beginning of dormancy