In biology, the BBCH-scale for beet describes the phenological development of beet plants using the BBCH-scale.
Phenology is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors. The word, coined by the Belgian botanist Charles Morren around 1849, is derived from the Greek φαίνω (phainō), "to show, to bring to light, make to appear" + λόγος (logos), amongst others "study, discourse, reasoning" and indicates that phenology has been principally concerned with the dates of first occurrence of biological events in their annual cycle. Examples include the date of emergence of leaves and flowers, the first flight of butterflies and the first appearance of migratory birds, the date of leaf colouring and fall in deciduous trees, the dates of egg-laying of birds and amphibia, or the timing of the developmental cycles of temperate-zone honey bee colonies. In the scientific literature on ecology, the term is used more generally to indicate the time frame for any seasonal biological phenomena, including the dates of last appearance.
The BBCH-scale is used to identify the phenological development stages of plants. BBCH-scales have been developed for a range of crop species where similar growth stages of each plant are given the same code.
The phenological growth stages and BBCH-identification keys of beet are:
| Growth stage | Code | Description |
|---|---|---|
| 0: Germination | 00 | Dry seed |
| 01 | Beginning of imbibition: seeds begins to take up water | |
| 03 | Seed imbibition complete (pellet cracked) | |
| 05 | Radicle emerged from seed (pellet) | |
| 07 | Shoot emerged from seed (pellet) | |
| 09 | Emergence: shoot emerges through soil surface | |
| 1: Leaf development (youth stage) | 10 | First leaf visible (pinhead-size): cotyledons horizontally unfolded |
| 11 | First pair of leaves visible, not yet unfolded (pea-size) | |
| 12 | 2 leaves (first pair of leaves) unfolded | |
| 14 | 4 leaves (2nd pair of leaves) unfolded | |
| 15 | 5 leaves unfolded | |
| 1 . | Stages continuous till . . . | |
| 19 | 9 and more leaves unfolded | |
| 3: Rosette growth (crop cover) | 31 | Beginning of crop cover: leaves cover 10% of ground |
| 32 | Leaves cover 20% of ground | |
| 33 | Leaves cover 30% of ground | |
| 34 | Leaves cover 40% of ground | |
| 35 | Leaves cover 50% of ground | |
| 36 | Leaves cover 60% of ground | |
| 37 | Leaves cover 70% of ground | |
| 38 | Leaves cover 80% of ground | |
| 39 | Crop cover complete: leaves cover 90% of ground | |
| 4: Development of harvestable vegetative plant parts Beet root | 49 | Beet root has reached harvestable size |
| 5: Inflorescence emergence (2nd year of growth) | 51 | Beginning of elongation of main stem |
| 52 | Main stem 20 cm long | |
| 53 | Side shoot buds visible on main stem | |
| 54 | Side shoots clearly visible on main stem | |
| 55 | First individual flower buds on side shoots visible | |
| 59 | First bracts visible; flower buds still closed | |
| 6: Flowering | 60 | First flowers open |
| 61 | Beginning of flowering: 10% of flowers open | |
| 62 | 20% of flowers open | |
| 63 | 30% of flowers open | |
| 64 | 40% of flowers open | |
| 65 | Full flowering: 50% of flowers open | |
| 67 | Flowering declining: 70% of flowers open or dry | |
| 69 | End of flowering: all flowers dry, fruit set visible | |
| 7: Development of fruit | 71 | Beginning of seed development: seeds visible in infructescence |
| 75 | Pericarp green; fruit still mouldable; perisperm milky; colour of seed coat: beige | |
| 8: Ripening | 81 | Beginning of ripening: pericarp green-brown, seed coat light brown |
| 85 | Pericarp light brown, seed coat reddish brown | |
| 87 | Pericarp hard, seed coat dark brown | |
| 89 | Fully ripe: seed coat final colour (specific to variety and species), perisperm hard | |
| 9: Senescence | 91 | Beginning of leaf discolouration |
| 93 | Most leaves yellowish | |
| 95 | 50% of leaves brownish | |
| 97 | Leaves dead | |
| 99 | Harvested product (seeds) | |