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
	01	Beginning of bud swelling
	03	End of bud swelling: green scales slightly separated
	07	Beginning of bud burst
	09	Green leaf tips visible
1: Leaf development	10	First leaves separating: green scales slightly open, leaves emerging
	11	First leaves visible[1]
	15	More leaves visible, not yet at full size
	19	First leaves fully expanded
3: Shoot development	31	Beginning of shoot growth: axes of developing shoots visible
	32	Shoots about 20% of final length
	39	Shoots about 90% of final length
5: Inflorescence emergence	51	Inflorescence buds swelling: buds closed, light green scales visible
	53	Bud burst: scales separated, floral tips visible
	55	Flowers visible, still closed (green bud), borne on single or multiflowered leafy or leafless inflorescences
	56	Flower petals elongating; sepals covering half corolla (white bud)
	57	Sepals open: petal tips visible; flowers with white or purplish petals, still closed
	59	Most flowers with petals forming a hollow ball
6: Flowering	60	First flowers open
	61	Beginning of flowering: about 10% of flowers open
	65	Full flowering: 50% of flowers open; first petals falling
	67	Flowers fading: majority of petals fallen
	69	End of flowering: all petals fallen
7: Development of fruit	71	Fruit set; beginning of ovary growth; beginning of fruitlets abscission
	72	Green fruit surrounded by sepal crown
	73	Some fruits slightly yellow: beginning of physiological fruit drop
	74	Fruits about 40% of final size. Dark green fruit: end of physiological fruit drop
	79	Fruits about 90% of final size
8: Maturity of fruit	81	Beginning of fruit colouring (colour-break)
	83	Fruit ripe for picking; fruit has not yet developed variety-specific colour
	85	Advanced ripening; increase in intensity of variety-specific colour
	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
	93	Beginning of senescence and abscission of old leaves
	97	Winter dormancy period

References

1. In Citrus the term "visible" replaces "unfolded" used for other fruit species. Leaf unfolding takes place precociously in citrus.

• Agusti, M.; S. Zaragoza; H. Bleiholder; L. Buhr; H. Hack; R. Klose; R. Stauss (1995). "Escala BBCH para la descripción de los estadios fenológicos del desarrollo de los agrios (Gén. Citrus)". Levante Agricola 3: 189–199.