Table 1.
Disease severity index (DSIf) and disease incidence (DIf, percentage of diseased plants) of clubroot visually assessed on 15 December 2017 on roots originating from each plot in field trials harvested in 2018 with clubroot-resistant cultivars cv. Mentor, cv. Alister, and cv. Archimedes and susceptible Cultivar mix. Sites were selected based on field abundance (gene copies g−1 soil) of Plasmodiophora brassicae DNA (Simrishamn 1,100,000; Tomelilla 2,500,000; Kumla 15,000; Hallsberg 2500).
| Treatment and Location | DSIf | DIf (%) | ||
|---|---|---|---|---|
| Simrishamn | ||||
| Cultivar mix | 52.1 | b * | 67.9 | b |
| cv. Mentor | 12.0 | c | 15.6 | cd |
| cv. Alister | 8.5 | c | 10.8 | cd |
| cv. Archimedes | 5.3 | c | 6.0 | cd |
| Tomelilla | ||||
| Cultivar mix | 55.4 | b | 62.5 | b |
| cv. Mentor | 8.3 | c | 11.2 | cd |
| cv. Alister | 8.0 | c | 9.2 | cd |
| cv. Archimedes | 2.4 | c | 4.0 | cd |
| Kumla | ||||
| Cultivar mix | 92.3 | a | 100.0 | a |
| cv. Mentor | 15.5 | c | 15.1 | cd |
| cv. Alister | 19.5 | c | 16.9 | c |
| cv. Archimedes | 8.3 | c | 6.4 | cd |
| Hallsberg | ||||
| Cultivar mix | 1.8 | c | 2.7 | cd |
| cv. Mentor | 0 | c | 0 | d |
| cv. Alister | 0 | c | 0 | d |
| cv. Archimedes | 0.7 | c | 2.0 | cd |
| p-value | <0.001 | <0.001 | ||
| Coefficient of variation | 56.1 | 47.4 | ||
* Different letters within each column indicate significant differences according to Tukey’s HSD-test (p < 0.05).