General Tube shape
Code describing the tuber outline, expressed as: (See figure 3)
| Code | Term | Description |
|---|---|---|
| 1 | Compressed (oblate) - major axis is the shortest axis | |
| 2 | Round - an almost circular outline. | |
| 3 | Ovate - an outline resembling an egg. The broadest part is within 1/3 of the distance from the stolon end | |
| 4 | Obovate - an outline which is inversely ovate and broadest within 1/3 of the distance from the apical end (rose or eye end). | |
| 5 | Elliptic - an outline showing the same breadth when measured at equal distance from both the stolon and apical ends. The outline is slightly acute at each end. | |
| 6 | Oblong - an almost rectangular outline with the sides nearly parallel but the corners rounded. The length/breadth ratio should not be more than 3/2 | |
| 7 | Long-Oblong - an oblong outline with a length/breadth ratio closer to 2/1 | |
| 8 | Elongate - a long rectangular outline with a length/breadth ratio equal to or more than 3/1 |