| Code | Definition | Number of Accessions |
| 1 | flowers have not formed yet | 1565 |
| 2 | flowers have formed, but bolls are not yet forming | 1845 |
| 3 | less than 1/2 open - bolls have already formed, but most are unopened | 2237 |
| 4 | more than 1/2 open - most bolls that have formed are opening | 2929 |
| 5 | complete - all or nearly all the bolls that have formed are open or are opening (cracking) | 2065 |
| 6 | half of the bolls on plants are open | 5 |
| 7 | plants have terminated their growth and opened all bolls | 3 |
| 9 | plot is segregating for this trait and a single score is not an accurate description or the variation is outside of the rating scale | 190 |