BBCH-scale (cotton)
In biology, the BBCH-scale for cotton describes the phenological development of cotton plants Gossypium hirsutum using the BBCH-scale.
The phenological growth stages and BBCH-identification keys of cotton are:
| Growth stage | Code | Description |
|---|---|---|
| 0: Germination | 00 | Dry seed |
| 01 | Beginning of seed imbibition | |
| 03 | Seed imbibition complete | |
| 05 | Radicle emerged from seed | |
| 06 | Elongation of radicle | |
| 07 | Hypocotyl with cotyledons breaking through seed coat | |
| 08 | Hypocotyl with cotyledons growing towards soil surface | |
| 09 | Emergence: hypocotyl with cotyledons breaking through soil surface (“crook stage”) | |
| 1: Leaf development (Main shoot) | 10 | Cotyledons completely unfolded1 |
| 11 | First true leaf unfolded1 | |
| 12 | 2nd true leaf unfolded1 | |
| 13 | 3rd true leaf unfolded1 | |
| 1 . | Stages continuous till . . . | |
| 19 | 9 or more true leaves unfolded;1 no side shoots visible2 | |
| 2: Formation of side shoots3 | 21 | First vegetative side shoot (2nd order) visible |
| 22 | 2 vegetative side shoots (2nd order) visible | |
| 23 | 3 vegetative side shoots (2nd order) visible | |
| 2 . | Stages continuous till . . . | |
| 29 | 9 or more vegetative side shoots (2nd order) visible | |
| 3: Main stem elongation (Crop cover) | 31 | Beginning of crop cover: 10% of plants meet between rows |
| 32 | 20% of plants meet between rows | |
| 33 | 30% of plants meet between rows | |
| 34 | 40% of plants meet between rows | |
| 35 | 50% of plants meet between rows | |
| 36 | 60% of plants meet between rows | |
| 37 | 70% of plants meet between rows | |
| 38 | 80% of plants meet between rows | |
| 39 | Canopy closure: 90% of the plants meet between rows | |
| 5: Inflorescence emergence (Main shoot) | 51 | First floral buds detectable (“pin-head square”)4 |
| 52 | First floral buds visible (“match-head square”)4 | |
| 55 | Floral buds distinctly enlarged | |
| 59 | Petals visible: floral buds still closed | |
| 6: Flowering | 60 | First flowers opened (sporadically within the population) |
| 61 | Beginning of flowering (“Early bloom”): 5–6 blooms / 25 ft of row (= 5–6 blooms / 7.5 meter of row) | |
| 65 | Full flowering: (“Mid bloom”): 11 and more blooms / 25 ft of row = 11 and more blooms / 7.5 meter of row | |
| 67 | Flowering finishing: majority of flowers faded (“Late bloom”) | |
| 69 | End of flowering | |
| 7: Development of fruits and seeds | 71 | About 10% of bolls have attained their final size |
| 72 | About 20% of bolls have attained their final size | |
| 73 | About 30% of bolls have attained their final size | |
| 74 | About 40% of bolls have attained their final size | |
| 75 | About 50% of bolls have attained their final size | |
| 76 | About 60% of bolls have attained their final size | |
| 77 | About 70% of bolls have attained their final size | |
| 78 | About 80% of bolls have attained their final size | |
| 79 | About 90% of bolls have attained their final size | |
| 8: Ripening of fruits and seeds | 80 | First open bolls on the first fruiting branches |
| 81 | Beginning of boll opening: about 10% of bolls open. Nodes Above White Flower (NAWF) | |
| 82 | About 20% of bolls open | |
| 83 | About 30% of bolls open. Nodes Above Cracked Boll (NACB) | |
| 84 | About 40% of bolls open | |
| 85 | About 50% of bolls open | |
| 86 | About 60% of bolls open | |
| 87 | About 70% of bolls open | |
| 88 | About 80% of bolls open | |
| 89 | About 90% of bolls open | |
| 9: Senescence | 91 | About 10% of leaves discoloured or fallen |
| 92 | About 20% of leaves discoloured or fallen | |
| 93 | About 30% of leaves discoloured or fallen | |
| 94 | About 40% of leaves discoloured or fallen | |
| 95 | About 50% of leaves discoloured or fallen | |
| 96 | About 60% of leaves discoloured or fallen | |
| 97 | Above ground parts of plant dead; plant dormant | |
| 99 | Harvested product (bolls and seeds) | |
1 Leaves are counted from the cotyledon node (= node 0)
2 Side shoot development may occur earlier, if there is a vegetative side shoot continue with principal growth stage 2. If there is a reproductive side shoot (fruiting branch) continue with the principal growth stage 5
3 Vegetative side shoots are counted from the cotyledon node
4 “pin-head square” or “match-head square” is the first square which forms at the first fruiting position of the first fruiting branch
References
Munger, L.; H. Bleiholder; H. Hack; M. Hess; R. Stauss; T. van den Boom; E. Weber (1998). "Phenological Growth Stages of the Peanut plant (Arachis hypogaea L.) Codification and Description according to the BBCH Scale – with figures". Journal of Agronomy and Crop Science 180 (2): 101–107. doi:10.1111/j.1439-037X.1998.tb00377.x.