In biology, the BBCH-scale for beans describes the phenological development of bean 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.
A bean is a seed of one of several genera of the flowering plant family Fabaceae, which are used for human or animal food.
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 bean are:
| Growth stage | Code | Description |
|---|---|---|
| 0: Germination | 00 | Dry seed |
| 01 | Beginning of seed imbibition | |
| 03 | Seed imbibition complete | |
| 05 | Radicle emerged from seed | |
| 07 | Hypocotyl with cotyledons breaking through seed coat | |
| 08 | Hypocotyl reaches the soil surface; hypocotyl arch visible | |
| 09 | Emergence: hypocotyl with cotyledons break through soil surface (“cracking stage”) | |
| 1: Leaf development | 10 | Cotyledons completely unfolded |
| 12 | 2 full leaves (first leaf pair unfolded) | |
| 13 | 3rd true leaf (first trifoliate leaf) unfolded | |
| 1 . | Stages continuous till . . . | |
| 19 | 9 or more leaves (2 full leaves, 7 or more trifoliate) unfolded | |
| 2: Formation of side shoots | 21 | First side shoot visible |
| 22 | 2nd side shoot visible | |
| 23 | 3rd side shoot visible | |
| 2 . | Stages continuous till . . . | |
| 29 | 9 or more side shoots visible | |
| 5: Inflorescence emergence | 51 | First flower buds visible |
| 55 | First flower buds enlarged | |
| 59 | First petals visible, flowers still closed | |
| 6: Flowering | 60 | First flowers open (sporadically within the population) |
| 61 | Beginning of flowering: 10% of flowers open1 Beginning of flowering2 | |
| 62 | 20% of flowers open1 | |
| 63 | 30% of flowers open1 | |
| 64 | 40% of flowers open1 | |
| 65 | Full flowering: 50% of flowers open1 Main flowering period2 | |
| 67 | Flowering finishing: majority of petals fallen or dry1 | |
| 69 | End of flowering: first pods visible1 | |
| 7: Development of fruit | 71 | 10% of pods have reached typical length1 Beginning of pot development2 |
| 72 | 20% of pods have reached typical length1 | |
| 73 | 30% of pods have reached typical length1 | |
| 74 | 40% of pods have reached typical length1 | |
| 75 | 50% of pods have reached typical length, beans beginning to fill out1 Main pod development period2 | |
| 76 | 60% of pods have reached typical length1 | |
| 77 | 70% of pods have reached typical length, pods still break cleanly1 | |
| 78 | 80% of pods have reached typical length1 | |
| 79 | Pods: individual beans easily visible1 | |
| 8: Ripening of fruit and seed | 81 | 10% of pods ripe (beans hard)1 Seeds beginning to mature2 |
| 82 | 20% of pods ripe (beans hard)1 | |
| 83 | 30% of pods ripe (beans hard)1 | |
| 84 | 40% of pods ripe (beans hard)1 | |
| 85 | 50% of pods ripe (beans hard)1 Main period of ripening2 | |
| 86 | 60% of pods ripe (beans hard)1 | |
| 87 | 70% of pods ripe (beans hard)1 | |
| 88 | 80% of pods ripe (beans hard)1 | |
| 89 | Fully ripe: pods ripe (beans hard)1 | |
| 9: Senescence | 97 | Plants dead |
| 99 | Harvested product | |
1 For varieties with limited flowering period
2 For varieties in which the flowering period is not limited