In biology, the BBCH-scale for peanut describes the phenological

Phenology

Phenology is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate...

 development of peanut

Peanut

The peanut, or groundnut , is a species in the legume or "bean" family , so it is not a nut. The peanut was probably first cultivated in the valleys of Peru. It is an annual herbaceous plant growing tall...

s using the BBCH-scale

BBCH-scale

The BBCH-scale is a scale used to identify the phenological development stages of a plant. A series of BBCH-scales have been developed for a range of crop species...

.

The phenological growth stages and BBCH-identification keys of peanuts are:

Growth stage	Code	Description
0: Germination	00	Dry seed Seed A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
	01	Beginning of seed imbibition Imbibition 'Imbibition' is defined as the displacement of one fluid by another immiscible fluid. This process is controlled and affected by a variety of factors...
	03	Seed imbibition complete
	05	Radicle Radicle In botany, the radicle is the first part of a seedling to emerge from the seed during the process of germination. The radicle is the embryonic root of the plant, and grows downward in the soil...  emerged from seed
	07	Hypocotyl Hypocotyl The hypocotyl is the stem of a germinating seedling, found below the cotyledons and above the radicle .-Dicots:...  with cotyledons breaking through seed coat
	08	Hypocotyl reaches the soil surface; hypocotyl arch visible
	09	Emergence: hypocotyl with cotyledons arising above soil surface (“cracking stage”)
1: Leaf development (main shoot)	10	Cotyledons completely unfolded1
	11	First true leaf (pinnate) unfolded1
	12	2nd true leaf (pinnate) unfolded1
	13	3rd true leaf (pinnate) unfolded1
	1 .	Stages continuous till . . .
	19	9 or more true leaves unfolded.1 No side shoots visible2
2: Formation of side shoots3	21	1st side shoot visible
	22	2nd side shoot visible
	23	3rd side shoot visible
	2 .	Stages continuous till . . .
	29	9 or more side shoots visible
3: Main stem Plant stem A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...  elongation (Crop cover)	31	Beginning of crop cover: 10% of plants meets between rows
	32	20% of plants meets between rows
	33	30% of plants meets between rows
	34	40% of plants meets between rows
	35	50% of plants meets between rows
	36	60% of plants meets between rows
	37	70% of plants meets between rows
	38	80% of plants meets between rows
	39	Crop cover complete: 90% of plants meets between rows
5: Inflorescence Inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...  emergence	51	First inflorescence Inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...  buds visible
	55	First individual flower buds visible
	59	First flower petals visible. Flower buds still closed
6: Flowering	61	Beginning of flowering
	62	First carpophore pegs visible
	63	Continuation of flowering
	64	First carpophore pegs visibly elongated
	65	Full flowering
	66	First carpophore pegs penetrating the soil
	67	Flowering declining4
	68	Tip of first carpophore pegs growing horizontally in the soil
	69	End of flowering4
7: Development of fruits and seeds	71	Beginning of pod development: tip of first carpophore pegs swollen (at least twice the original diameter)
	73	Continuation of pod development: beginning of pod filling: first pods have attained final size and are ripening
	75	Main phase of pod development: continuation of pod filling
	77	Advanced pod filling
	79	Fresh seeds fill the cavity of the pods which have attained their final size
8: Ripening of fruits and seeds5	81	Beginning of ripening: about 10% of pods developed to final size are ripe
	82	About 20% of pods developed to final size are ripe
	83	Continuation of ripening: about 30% of pods developed to final size are ripe
	84	About 40% of pods developed to final size are ripe
	85	Main phase of ripening: about 50% of pods developed to final size are ripe
	86	About 60% of pods developed to final size are ripe
	87	Advanced ripening: about 70% of pods developed to final size are ripe
	88	About 80% of pods developed to final size are ripe
	89	Full maturity: nearly all pods developed to final size are ripe
9: Senescence Senescence Senescence or biological aging is the change in the biology of an organism as it ages after its maturity. Such changes range from those affecting its cells and their function to those affecting the whole organism...	91	About 10% of above ground parts of plant dry
	92	About 40% of above ground parts of plant dry
	93	About 30% of above ground parts of plant dry
	94	About 40% of above ground parts of plant dry
	95	About 50% of above ground parts of plant dry
	96	About 60% of above ground parts of plant dry
	97	Above ground parts of plant dead
	99	Harvested product

1 Leaves are counted from the cotyledon node (= node 0)

2 Side shoot development may occur earlier; in this case continue with principal growth stage 2

4 Only for varieties with a determinate flowering period

5 Criteria of maturity: Pericarp hard, with distinct texture, can be split open easily;