Classification of the salt (NaCl) and freezing tolerance of six Crataegus genotypes based on the percentage reduction of the performance index (PIp).
| Treatment | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 9% NaCl | −7°C | 6% NaCl + −7°C | −7°C + 6% NaCl | |||||||
| Genotype | % Reduc. | Toler. classif. | % Reduc. | Toler. classif. | % Reduc. | Toler. classif. | % Reduc. | Toler. classif. | Mean % reduc. | Overall toler. classif. |
| C. maximowiczii (n = 3) | 77.6 | S | 22.7 | T | 68.6 | I-S | 17.4 | T | 46.6 | I |
| C. grignonensis (n = 4) | 41.1 | I | 94.7 | S | 28.9 | T | 38.1 | I-T | 50.7 | I |
| C. laevigata ‘Pauls Scarlet’ (n = 4) | 2.4 | VT | 78.1 | S | 68.3 | I-S | 70.2 | S | 54.8 | I |
| C. monogyna (n = 12) | 67.4 | I-S | 74.2 | S | 48.9 | I | 82.0 | S | 68.1 | I-S |
| C. prunifolia (n = 6) | 53.6 | I | 96.5 | S | 58.2 | I-S | 91.7 | S | 75.0 | S |
| C. oxyacantha (n = 5) | 50.3 | I | 87.5 | S | 90.4 | S | 78.2 | S | 76.6 | S |
| Percentage reduction in PIp | Tolerance classification | |||||||||
| 0%–15% | Very Tolerant (VT) | |||||||||
| 16%–30% | Tolerant (T) | |||||||||
| 31%–40% | Intermediate-Tolerant (I-T) | |||||||||
| 41%–55% | Intermediate (I) | |||||||||
| 56%–70% | Intermediate–Sensitive (I–S) | |||||||||
| ≥71% | Sensitive | |||||||||
All values mean of n trees, 30 leaves per tree.