In biology, the BBCH-scale for coffee 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.
Coffee is a brewed drink prepared from roasted coffee beans, the seeds of berries from certain Coffea species. The genus Coffea is native to tropical Africa and Madagascar, the Comoros, Mauritius, and Réunion in the Indian Ocean. Coffee plants are now cultivated in over 70 countries, primarily in the equatorial regions of the Americas, Southeast Asia, Indian subcontinent, and Africa. The two most commonly grown are C. arabica and C. robusta. Once ripe, coffee berries are picked, processed, and dried. Dried coffee seeds are roasted to varying degrees, depending on the desired flavor. Roasted beans are ground and then brewed with near-boiling water to produce the beverage known as coffee.
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 coffee plants are:
| Growth stage | Code | Description |
|---|---|---|
| 0: Germination, vegetative propagation | 00 | Dry seed (11-12% moisture content), beige color if parchment present or bluish-green if parchment and silver skin removed. Cutting (orthotropic, mononodal, 60 mm long, two half trimmed leaves). Stump with bulky nodes and no buds visible |
| 01 | Beginning of seed imbibition, bean swollen, whitish, no radicle visible. Cutting planted in rooting media, no shoots visible, no callus visible | |
| 02 | Seed imbibition complete, bean whitish, small swelling visible at one end of bean where the embryo is located. Callus formation begins on cuttings. Bud burst start on stumps | |
| 05 | Seed radicle protrusion and hooking. Shoot and root formation on the cuttings. Green, rounded buds visible on the stumps | |
| 06 | Elongation of radicle, formation of root hairs and lateral roots on seeds and cuttings. | |
| 07 | Hypocotyl with cotyledons breaking through the seed coat. Cuttings have formed shoots and branched roots. | |
| 09 | Emergence: Seeds have emerged from soil and show the hypocotile with cotyledons still enclosed in the parchment. The cuttings present roots 6–7 cm. long and shoots with 1-2 nodes. Stumps show sprouts with first leaf initials. | |
| 1: Leaf development on main shoot of the young plant, and branches of the coffee tree | 10 | Cotyledons completely unfolded. First pair of true leaves separating on shoot or first pair of true leaves separating on branch of the coffee tree |
| 11 | first leaf pair unfolded, not yet at full size. Leaves are light green or bronze | |
| 12 | 2 leaf pairs unfolded, not yet at full size. Leaves are light green or bronze | |
| 13 | 3 leaf pairs unfolded, not yet full size. The third leaf pair from apex is dark green | |
| 14 | 4 leaf pairs unfolded. The fourth leaf pair from apex is dark green and has reached full size | |
| 1. | Stages continues till... | |
| 19 | 9 or more leaf pairs unfolded | |
| 2: Formation of branches (only for plants in the field) | 20 | First pair of primary branches are visible |
| 21 | 10 pair of primary branches visible | |
| 22 | 20 pair of primary branches visible | |
| 23 | 30 pair of primary branches visible | |
| 2. | Stages continues till... | |
| 29 | 90 or more pairs of primary branches visible | |
| 3: Branch elongation | 31 | 10 nodes present in the branch(es) |
| 32 | 20 nodes present in the branch(es) | |
| 3. | Stages continues till... | |
| 39 | 90 or more nodes present in the branch(es) | |
| 5: Inflorescence emergence | 51 | Inflorescence buds swelling in leaf axils |
| 53 | Inflorescence buds burst and covered by brown mucilage; no flowers visible | |
| 57 | Flowers visible, still closed and tightly join, borne on multiflowered inflorescence (3-4 flowers per inflorescence) | |
| 58 | Flowers visible, untight, still closed, petals 4–6 mm long and green (dormant stage) | |
| 59 | Flowers with petals elongated ( 6–10 mm long), still closed and white color. | |
| 6: Flowering | 60 | First flowers open |
| 61 | 10% of flowers open | |
| 63 | 30% of flowers open | |
| 65 | 50% of flowers open | |
| 67 | 70% of flowers open | |
| 69 | 90% of flowers open | |
| 7: Development of fruit | 70 | Fruits visible as small yellowish berries |
| 71 | Fruit set: Beginning of berry growth. Fruits have reached 10% of final size (pinheads). | |
| 73 | Fruits are light green and contents are liquid and crystalline. Fruits have reached 30% of final size (fast growth). | |
| 75 | Fruits are light green and its contents are liquid and crystalline. Fruits have reached 50% of final size. | |
| 77 | Fruits are dark green and its contents are solid and white. Fruits have reached 70% of final size. | |
| 79 | Fruits are pale green and its contents are solid and white. Physiological maturity is complete. Fruits have reached 90% of final size. | |
| 8: Ripening of fruit and seed | 81 | Beginning of change of fruit coloration from pale green to yellow or red |
| 85 | Increase in intensity (variety-specific), yellow or red, fruit color; fruit not yet ready for picking. | |
| 88 | Fruit is fully ripe color and ready for picking. | |
| 89 | Overripe; beginning of darkening or drying; fruits stay on the tree or abscission begins. | |
| 9: Senescence | 90 | Shoots have completed their development; the plant appears of an intense dark green color, leaves are of normal size and harvest locates at the bottom part of the plant. |
| 93 | Older leaves change its color from deep green to yellow with red spots, and fall specially at harvesting time. | |
| 94 | The foliage changes to a pale green color. Defoliation is observed on the bottom part of the main stem and lower branches. | |
| 97 | The production zone has moved towards the upper parts in the main shoot and outer parts of branches, leaves are of smaller size than normal, strong defoliation is observed on the bottom and inner part of the plant, some dead branches are observed at the bottom. | |
| 98 | The production zone is limited to a very few branches on the top of the shoot and a very few nodes on the tip of these branches, and the plant is heavily defoliated. A high-degree of senescence has been reached. 90% or more of the harvest completed. | |
| 99 | Post harvest or storage treatments | |