# BBCH-scale (potato)

The BBCH-scale (potato) identifies the phenological development stages of a potato (Solanum tuberosum). It is a plant species-specific version of the BBCH-scale.
| Growth stage | Code | Code | Description |
| Growth stage | 2 digit | 3 digit | Description |
| 0: Sprouting/Germination | 00 | 000 | Innate or enforced dormancy, Dry seed tuber not sprouted |
| 0: Sprouting/Germination | 01 | 001 | Beginning of sprouting: Beginning of sprouts visible (< 1 mm) seed imbibition |
| 0: Sprouting/Germination | 02 | 002 | Sprouts upright (< 2 mm) |
| 0: Sprouting/Germination | 03 | 003 | End of dormancy: sprouts 2–3 mm Seed imbibition complete |
| 0: Sprouting/Germination | 05 | 005 | Beginning of root formation Radicle (root) emerged from seed |
| 0: Sprouting/Germination | 07 | 007 | Beginning of stem formation Hypocotyl with cotyledons breaking |
| 0: Sprouting/Germination | 08 | 008 | Stems growing towards soil surface, Hypocotyl with formation of scale leaves in the axils; cotyledons growing of which stolons will develop later towards soil surface |
| 0: Sprouting/Germination | 09 | 009 | Emergence: stems break through soil surface; cotyledons break through soil surface |
| 0: Sprouting/Germination | 09 | 021–029$^1$ | |
| 1: Leaf development | 10 | 100 | From tuber: first leaves begin to extend From seed: cotyledons completely unfolded |
| 1: Leaf development | 11 | 101 | First leaf of main stem unfolded (> 4 cm) |
| 1: Leaf development | 12 | 102 | Second leaf of main stem unfolded (> 4 cm) |
| 1: Leaf development | 13 | 103 | Third leaf of main stem unfolded (> 4 cm) |
| 1: Leaf development | 1 . | 10 . | Stages continuous till ... |
| 1: Leaf development | 19 | 109 | Nine or more leaves of main stem unfolded (> 4 cm) (2 digit);$^2$ 9 leaves of main stem unfolded (> 4 cm) (3 digit) |
| 1: Leaf development | 19 | 110 | Tenth leaf of main stem unfolded (> 4 cm) |
| 1: Leaf development | 11 . | | Stages continuous till ... |
| 1: Leaf development | 11 . | 119 | Nineteenth leaf of main stem unfolded (> 4 cm) |
| 1: Leaf development | 11 . | 121 | First leaf of second order branch above first inflorescence unfolded (> 4 cm) |
| 1: Leaf development | 11 . | 122 | Second leaf of second order branch above first inflorescence unfolded (> 4 cm) |
| 1: Leaf development | 12 . | | Stages continuous till ... |
| 1: Leaf development | 12 . | 131 | First leaf of third order branch above second inflorescence unfolded (> 4 cm) |
| 1: Leaf development | 12 . | 132 | Second leaf of third order branch above second inflorescence unfolded (> 4 cm) |
| 1: Leaf development | 13 . | | Stages continuous till ... |
| 1: Leaf development | 13 . | 1NX | Xth leaf of nth order branch above (n-1)th inflorescence unfolded (> 4 cm) |
| 2: Formation of basal side shoots below and above soil surface (main stem) | 21 | 201 | First basal side shoot visible (> 5 cm) |
| 2: Formation of basal side shoots below and above soil surface (main stem) | 22 | 202 | Second basal side shoot visible (> 5 cm) |
| 2: Formation of basal side shoots below and above soil surface (main stem) | 23 | 203 | Third basal side shoot visible (> 5 cm) |
| 2: Formation of basal side shoots below and above soil surface (main stem) | 2 . | 20 . | Stages continuous till ... |
| 2: Formation of basal side shoots below and above soil surface (main stem) | 29 | 209 | Nine or more basal side shoots visible (> 5 cm) |
| 3: Main stem elongation (crop cover) | 31 | 301 | Beginning of crop cover: 10% of plants meet between rows |
| 3: Main stem elongation (crop cover) | 32 | 302 | 20% of plants meet between rows |
| 3: Main stem elongation (crop cover) | 33 | 303 | 30% of plants meet between rows |
| 3: Main stem elongation (crop cover) | 34 | 304 | 40% of plants meet between rows |
| 3: Main stem elongation (crop cover) | 35 | 305 | 50% of plants meet between rows |
| 3: Main stem elongation (crop cover) | 36 | 306 | 60% of plants meet between rows |
| 3: Main stem elongation (crop cover) | 37 | 307 | 70% of plants meet between rows |
| 3: Main stem elongation (crop cover) | 38 | 308 | 80% of plants meet between rows |
| 3: Main stem elongation (crop cover) | 39 | 309 | Crop cover complete: about 90% of plants meet between rows |
| 4: Tuber formation | 40 | 400 | Tuber initiation: swelling of first stolon tips to twice the diameter of subtending stolon |
| 4: Tuber formation | 41 | 401 | 10% of total final tuber mass reached |
| 4: Tuber formation | 42 | 402 | 20% of total final tuber mass reached |
| 4: Tuber formation | 43 | 403 | 30% of total final tuber mass reached |
| 4: Tuber formation | 44 | 404 | 40% of total final tuber mass reached |
| 4: Tuber formation | 45 | 405 | 50% of total final tuber mass reached |
| 4: Tuber formation | 46 | 406 | 60% of total final tuber mass reached |
| 4: Tuber formation | 47 | 407 | 70% of total final tuber mass reached |
| 4: Tuber formation | 48 | 408 | Maximum of total tuber mass reached, tubers detach easily from stolons, skin set not yet complete (skin easily removable with thumb) |
| 4: Tuber formation | 49 | 409 | Skin set complete: (skin at apical end of tuber not removable with thumb) 95% of tubers in this stage |
| 5: Inflorescence (cyme) emergence | 51 | 501 | First individual buds (1–2 mm) of first inflorescence visible (main stem) |
| 5: Inflorescence (cyme) emergence | 55 | 505 | Buds of first inflorescence extended to 5 mm |
| 5: Inflorescence (cyme) emergence | 59 | 509 | First flower petals of first inflorescence visible |
| 5: Inflorescence (cyme) emergence | 59 | 521 | Individual buds of second inflorescence visible (second order branch) |
| 5: Inflorescence (cyme) emergence | 59 | 525 | Buds of second inflorescence extended to 5 mm open (main stem) |
| 5: Inflorescence (cyme) emergence | 59 | 529 | First flower petals of second inflorescence visible above sepals |
| 5: Inflorescence (cyme) emergence | 59 | 531 | Individual buds of third inflorescence visible (third order branch) |
| 5: Inflorescence (cyme) emergence | 59 | 535 | Buds of third inflorescence extended to 5 mm |
| 5: Inflorescence (cyme) emergence | 59 | 539 | First flower petals of third inflorescence visible above sepals |
| 5: Inflorescence (cyme) emergence | 5N . | | Nth inflorescence emerging |
| 6: Flowering | 60 | 600 | First open flowers in population |
| 6: Flowering | 61 | 601 | Beginning of flowering: 10% of flowers in the first inflorescence open (main stem) |
| 6: Flowering | 62 | 602 | 20% of flowers in the first inflorescence open |
| 6: Flowering | 63 | 603 | 30% of flowers in the first inflorescence open |
| 6: Flowering | 64 | 604 | 40% of flowers in the first inflorescence open |
| 6: Flowering | 65 | 605 | Full flowering: 50% of flowers in the first inflorescence open |
| 6: Flowering | 66 | 606 | 60% of flowers in the first inflorescence open |
| 6: Flowering | 67 | 607 | 70% of flowers in the first inflorescence open |
| 6: Flowering | 68 | 608 | 80% of flowers in the first inflorescence open |
| 6: Flowering | 69 | 609 | End of flowering in the first inflorescence |
| 6: Flowering | | 621 | Beginning of flowering: 10% of flowers in the second inflorescence open (second order branch) |
| 6: Flowering | | 625 | Full flowering: 50% of flowers in the second inflorescence open |
| 6: Flowering | | 629 | End of flowering in the 2nd inflorescence |
| 6: Flowering | | 631 | Beginning of flowering: 10% of flowers in the third inflorescence open (third order branch) |
| 6: Flowering | | 635 | Full flowering: 50% of flowers in the third inflorescence open |
| 6: Flowering | | 639 | End of flowering in the third inflorescence |
| 6: Flowering | 6N . | | Nth inflorescence flowering |
| 6: Flowering | 6N . | 6N9 | End of flowering |
| 7: Development of fruit | 70 | 700 | First berries visible |
| 7: Development of fruit | 71 | 701 | 10% of berries in the first fructification have reached full size (main stem) |
| 7: Development of fruit | 72 | 702 | 20% of berries in the first fructification have reached full size |
| 7: Development of fruit | 73 | 703 | 30% of berries in the first fructification have reached full size |
| 7: Development of fruit | 7 . | 70 . | Stages continuous till ... |
| 7: Development of fruit | 7 . | 721 | 10% of berries in the second fructification have reached full size (second order branch) |
| 7: Development of fruit | 7N . | | Development of berries in nth fructification |
| 7: Development of fruit | 7N . | 7N9 | Nearly all berries in the nth fructification have reached full size (or have been shed) |
| 8: Ripening of fruit and seed | 81 | 801 | Berries in the first fructification still green, seed light-coloured (main stem) |
| 8: Ripening of fruit and seed | 85 | 805 | Berries in the first fructification ochre-coloured or brownish |
| 8: Ripening of fruit and seed | 89 | 809 | Berries in the first fructification shrivelled, seed dark |
| 8: Ripening of fruit and seed | 89 | 821 | Berries in the second fructification still green, seed light-coloured (second order branch) |
| 8: Ripening of fruit and seed | 8N . | | Ripening of fruit and seed in nth fructification |
| 9: Senescence | 91 | 901 | Beginning of leaf yellowing |
| 9: Senescence | 93 | 903 | Most of the leaves yellowish |
| 9: Senescence | 95 | 905 | 50% of the leaves brownish |
| 9: Senescence | 97 | 907 | Leaves and stem dead, stems bleached and dry |
| 9: Senescence | 99 | 909 | Harvested product |
1 For second generation sprouts 2 Stem development stops after termination of main stem by an inflorescence. Branches arise from axils of upper leaves of the main stem, exhibiting a sympodial branching pattern