Cornus cultivars susceptible to powdery mildew under field conditions 1998–2002.
| Cornus species | Cultivar | Mean powdery mildew severityz | Mean | ||||
|---|---|---|---|---|---|---|---|
| 1998 | 1999 | 2000 | 2001 | 2002 | |||
| C. florida | Little Princess | 1.0 hiy | 0.4 ij | 2.5 ghi | 3.3 ab | 3.0 def | 2.0 |
| C. kousa | Bush Pink | 2.0 fgh | 0.4 ij | 2.9 efgh | 2.6 cde | ____ | 2.0 |
| C. florida | World’s Fair | 2.0 fgh | 0.5 hij | 2.6 fgh | 2.5 cde | 2.7 efg | 2.1 |
| C. nutalli | Boyd | ____ | 1.0 fghi | 3.0 i | 2.1 ef | 2.5 fg | 2.2 |
| C. kousa | Spring Grove | 1.7 fghi | 0.5 hij | 2.3 hi | 2.5 cde | 4.3 ab | 2.3 |
| C. florida | Pink Beauty | 2.0 ef | 2.5 | 2.5 cde | 3.0 bc | 2.5 efg | 2.5 |
| C. florida | Pygmy | 1.7 gh | 2.4 | 3.5 bcde | 2.6 bcd | 2.3 fg | 2.5 |
| C. florida | Sterling silver | ____ | 2.3 | 1.8 i | 3.3 ab | 2.8 ef | 2.6 |
| C. florida | Plena | 1.0 hi | 2.2 | 3.0 defgh | 3.0 bc | 4.0 ab | 2.6 |
| C. florida | Red Beauty | 3.3 bcd | 2.7 | 3.5 bcde | 2.3 cde | 2.3 fg | 2.8 |
| C. florida | Cherokee | 3.0 bcd | 2.5 | ____ | ____ | ____ | 2.8 |
| C. florida | Barton | 2.3 def | 2.3 bcd | 2.4 hi | 2.0 ef | 5.0 a | 2.8 |
| C. florida | Cherokee Chief | 3.3 bc | 2.7 | 3.6 bcd | 1.4 gh | 3.8 abc | 3.0 |
| C. florida | Cherokee Princess | 3.0 bcd | 3.0 | 3.4 bcde | 3.1 bc | 2.7 efg | 3.0 |
| C. florida | Wonderberry | 3.0 bcd | 3.1 | 3.0 defh | ____ | ____ | 3.0 |
| C. florida | Cloud 9 | 2.7 def | 3.0 | 3.5 bcde | 2.1 efg | 4.5 a | 3.2 |
| C. florida | Rainbow | 3.0 bcd | 2.8 | 3.8 bcd | 2.0 efg | 4.3 ab | 3.2 |
| C. florida | Rubra | 3.7 bc | 3.3 | 2.9 abc | 2.9 bcd | 3.2 cde | 3.2 |
| C. florida | Cherokee Sunset | 5.0 a | 2.5 bcd | 3.3 cdef | 2.5 cde | 4.0 ab | 3.5 |
| C. florida | Ozark Spring | 2.3 ef | 3.2 ab | 4.6 a | 3.5 ab | 3.5 bcd | 3.4 |
| C. florida | Purple Glory | 4.0 ab | 3.6 a | 4.0 abc | 4.0 a | 5.0 a | 4.1 |
| LSD(0.05) | 1.1 | 1.1 | 0.9 | 0.8 | 1.1 | ||
↵z Disease severity readings 1 = 1% to 10%, 2 = 11% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = 76% to 100% plant infection.
↵y Statistical differences between cultivars are presented across Tables 1–2. Numbers followed by same letters in the same column are statistically similar at P = 0.05 according to least significant differences calculated by Statistical Analysis Systems (SAS).