HORTICULTURE
Apple Variety Fire Blight Susceptability in 1991
| Severity of fire blight on 2- and 3-year-old apple trees on M.7a or M.7 EMLA rootstocks at the Southwest Michigan Research and Extension Center following a severe epidemic in 1991. | ||
| Severity scores for 84 Apple Cultivars y,z | ||
| Variety | July 17 |
Sept. 11 |
| Moderately Resistant | ||
| Red Chief (Campbell) Delicious | 10.0 |
9.7 |
| Nured Delicious | 9.7 |
9.5 |
| Starkrimson Delicious | 9.5 |
9.5 |
| Liberty | 9.7 |
9.2 |
| Keepsake | 9.7 |
9.2 |
| Nured Winesap | 9.5 |
9.2 |
| Early Red One Delicious | 9.2 |
9.2 |
| Top Spur Delicious | 9.2 |
9.2 |
| Cascade Spur Delicious | 9.2 |
9.2 |
| Lurared | 9.2 |
8.7 |
| Melrose | 9.0 |
8.5 |
| Starkspur Ultra Stripe Delicious | 9.0 |
8.5 |
| Starkspur Supreme Red Delicious | 8.7 |
8.5 |
| Starkspur Compact Red Delicious | 8.7 |
8.5 |
| Intermediate Resistance | ||
| Red Max | 9.2 |
8.2 |
| Empire | 8.7 |
8.2 |
| Ace Delicious | 8.7 |
8.0 |
| Scarlet Spur Delicious | 8.7 |
8.0 |
| Jonamac | 8.2 |
8.0 |
| Marshall Mcintosh | 8.2 |
8.0 |
| Sturdeespur Delicious | 8.5 |
7.7 |
| Freedom | 8.0 |
7.7 |
| Macspur | 8.0 |
7.7 |
| Lysgolden | 9.2 |
7.5 |
| DixiRed Delicious | 8.5 |
7.5 |
| Regent | 8.0 |
7.2 |
| Prima | 7.7 |
7.2 |
| Classic Delicious | 8.5 |
7.0 |
| Dana Red Delicious | 8.2 |
7.0 |
| Lustre Elstar | 8.0 |
7.0 |
| Scarlet Gala | 8.0 |
7.0 |
| Swiss Gormet (Arlet) | 7.7 |
7.0 |
| Stamared | 7.7 |
7.0 |
| Ozark Gold | 7.7 |
7.0 |
| Pioneer Mac | 7.5 |
7.0 |
| Mor Spur Mac | 7.7 |
7.0 |
| Akane | 8.0 |
6.7 |
| Red Winesap | 8.0 |
6.7 |
| Golden Glory | 8.0 |
6.7 |
| Gold Spur | 7.7 |
6.7 |
| Perfect Spur Criterion | 7.5 |
6.7 |
| Red Chief (Mercier) Delicious | 7.5 |
6.7 |
| Granny Smith | 7.0 |
6.7 |
| Moderately Susceptible | ||
| Summer Treat | 8.2 |
6.5 |
| Red Fuji | 8.0 |
6.5 |
| Smoothee | 7.2 |
6.5 |
| Stark Gala | 7.2 |
6.5 |
| Mutsu | 7.0 |
6.2 |
| Red Cort | 6.7 |
6.2 |
| Golden Delicious | 6.7 |
6.2 |
| Honeygold | 7.2 |
6.0 |
| Imperial Gala | 7.2 |
6.0 |
| Super Chief Red Delicious | 6.7 |
6.0 |
| Moderately Susceptible | ||
| Fulford Gala | 7.2 |
5.7 |
| Royal Gala | 7.0 |
5.7 |
| Virginiagold | 6.5 |
5.7 |
| Staybrite Staman | 7.5 |
5.5 |
| Red Fuji #4 | 6.5 |
5.5 |
| Jonagold | 6.2 |
5.5 |
| Blushing Golden | 7.5 |
5.2 |
| Very Susceptible | ||
| Spur GalaGoRed | 7.0 |
5.0 |
| Red Fuji Nagano | 6.7 |
5.0 |
| Nicobel Jonagold | 5.2 |
5.0 |
| Spigold | 5.2 |
4.7 |
| EarliJon | 6.5 |
4.5 |
| Fuji | 5.5 |
4.5 |
| Northwest Greening | 5.5 |
4.5 |
| Ultra Red Jonathan | 5.2 |
4.5 |
| Berts Special | 5.0 |
4.5 |
| Prime Gold | 5.0 |
4.5 |
| Double Red Jonathan | 6.7 |
4.2 |
| Braeburn | 5.7 |
4.0 |
| Geneva Early | 5.2 |
4.0 |
| Super Jon | 4.7 |
4.0 |
| Earligold | 5.5 |
3.7 |
| Jonnee | 4.7 |
3.5 |
| Idared | 5.7 |
3.5 |
| Starkspur Law Rome | 4.7 |
3.2 |
| Jonafree | 3.2 |
3.2 |
| Red Yorking | 3.7 |
3.0 |
| Nittany | 4.0 |
2.7 |
| Early Spur Rome | 4.2 |
2.5 |
| Ginger Gold | 5.0 |
2.2 |
| Nured Jon | 3.0 |
1.7 |
| Y Data adapted from T. M. Thomas and A. L. Jones, 1992. Plant Dis. 76:1049-1052. | ||
| Z Final USDA rating scores were
based on the scale: 10 = 0%; 9 = 1-3%; 8 = 4-6%; 7 = 7-12%; 6 = 13-25%; 5 = 26-50%; 4 = 51-75%; 3 = 76-88%; 2 = 89-99%; and 1 = 100% of the tree blighted. Data are mean rating scores for four trees |
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Compare this table with the fire blight table from 2000