Statistics of girdling time for categories of elms observed to have Dutch elm disease.
| Category | No. | Percent of total | Girdling time (min) | |
|---|---|---|---|---|
| Mean | Standard deviation | |||
| Convoluted | 20 | 33 | 5.0** | 2.059 |
| Nonconvoluted | ||||
| 10-20 in. dbh | 17 | 28 | 2.5** | 0.881 |
| 21-38 in. dbh | 24 | 39 | 3.5** | 1.215 |
| All elms | 61 | 100 | 3.7 | 1.749 |
↵a**Means significantly different from each other at the 0.01 level, student’s t test.