# BBCH-scale (citrus)

The BBCH-scale for citrus is a classification system used in biology to describe the phenological development of citrus plants using the BBCH-scale.
The phenological growth stages and BBCH-identification keys of citrus plants are:
| Growth stage | Code | Description |
| 0: Sprouting/Bud development | 00 | Dormancy: leaf and inflorescence buds undifferentiated, closed and covered by green scales |
| 0: Sprouting/Bud development | 01 | Beginning of bud swelling |
| 0: Sprouting/Bud development | 03 | End of bud swelling: green scales slightly separated |
| 0: Sprouting/Bud development | 07 | Beginning of bud burst |
| 0: Sprouting/Bud development | 09 | Green leaf tips visible |
| 1: Leaf development | 10 | First leaves separating: green scales slightly open, leaves emerging |
| 1: Leaf development | 11 | First leaves visible |
| 1: Leaf development | 15 | More leaves visible, not yet at full size |
| 1: Leaf development | 19 | First leaves fully expanded |
| 3: Shoot development | 31 | Beginning of shoot growth: axes of developing shoots visible |
| 3: Shoot development | 32 | Shoots about 20% of final length |
| 3: Shoot development | 39 | Shoots about 90% of final length |
| 5: Inflorescence emergence | 51 | Inflorescence buds swelling: buds closed, light green scales visible |
| 5: Inflorescence emergence | 53 | Bud burst: scales separated, floral tips visible |
| 5: Inflorescence emergence | 55 | Flowers visible, still closed (green bud), borne on single or multiflowered leafy or leafless inflorescences |
| 5: Inflorescence emergence | 56 | Flower petals elongating; sepals covering half corolla (white bud) |
| 5: Inflorescence emergence | 57 | Sepals open: petal tips visible; flowers with white or purplish petals, still closed |
| 5: Inflorescence emergence | 59 | Most flowers with petals forming a hollow ball |
| 6: Flowering | 60 | First flowers open |
| 6: Flowering | 61 | Beginning of flowering: about 10% of flowers open |
| 6: Flowering | 65 | Full flowering: 50% of flowers open; first petals falling |
| 6: Flowering | 67 | Flowers fading: majority of petals fallen |
| 6: Flowering | 69 | End of flowering: all petals fallen |
| 7: Development of fruit | 71 | Fruit set; beginning of ovary growth; beginning of fruitlets abscission |
| 7: Development of fruit | 72 | Green fruit surrounded by sepal crown |
| 7: Development of fruit | 73 | Some fruits slightly yellow: beginning of physiological fruit drop |
| 7: Development of fruit | 74 | Fruits about 40% of final size. Dark green fruit: end of physiological fruit drop |
| 7: Development of fruit | 79 | Fruits about 90% of final size |
| 8: Maturity of fruit | 81 | Beginning of fruit colouring (colour-break) |
| 8: Maturity of fruit | 83 | Fruit ripe for picking; fruit has not yet developed variety-specific colour |
| 8: Maturity of fruit | 85 | Advanced ripening; increase in intensity of variety-specific colour |
| 8: Maturity of fruit | 89 | Fruit ripe for consumption; fruit has typical taste and firmness; beginning of senescence and fruit abscission |
| 9: Senescence, beginning of dormancy | 91 | Shoot growth complete; foliage fully green |
| 9: Senescence, beginning of dormancy | 93 | Beginning of senescence and abscission of old leaves |
| 9: Senescence, beginning of dormancy | 97 | Winter dormancy period |