Table 1.
Average monthly weather conditions during the experiment (2019–2022 years)
| Month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 47 | 44 | 39 | 48 | 55 | 87 | 87 | 59 | 43 | 33 | 43 | 48 |
| Air temperature (°C) | −5.7 | −4.2 | 0.4 | 8.5 | 14.6 | 17.6 | 19 | 18.2 | 13.6 | 7.6 | 2.1 | −2.4 |
| Relative air humidity (%) | 86 | 85 | 82 | 68 | 64 | 66 | 67 | 68 | 73 | 80 | 87 | 88 |
Figure 1.
Crown formation: slender spindle (1), ballerina (2), and French axis (3)
Table 2.
Parameters of vegetative growth of apple trees depending on the form of the crown and the term of pruning (averaged data for 2019–2022 years)
| Crown form | Term of pruning | Stem diameter increase (mm) | Number of shoots (pcs. per tree) | Shoot length (cm) | Total shoot length (m per tree) |
|---|---|---|---|---|---|
| ‘Fuji’ | |||||
| Slender spindle | winter (control) | 4.8 ± 0.1* ab | 49 ± 3 ab | 22.1 ± 1.8 c | 10.6 ± 0.3 ab |
| winter and summer | 4.1 ± 0.1 cd | 54 ± 5 a | 16.0 ± 1.1 de | 8.6 ± 0.8 bc | |
| French axis | winter | 5.2 ± 0.2 a | 36 ± 3 c | 28.8 ± 2.7 a | 10.3 ± 0.8 ab |
| winter and summer | 4.6 ± 0.2 abc | 41 ± 2 bc | 27.2 ± 2.6 ab | 11.0 ± 0.3 a | |
| Ballerina | winter | 4.4 ± 0.2 bcd | 49 ± 3 ab | 20.3 ± 1.3 bcd | 9.9 ± 0.8 abc |
| winter and summer | 3.8 ± 0.2 d | 54 ± 5 a | 14.7 ± 0.7 e | 7.9 ± 0.8 c | |
| ‘Honeycrisp’ | |||||
| Slender spindle | winter (control) | 6.5 ± 0.2 bc | 45 ± 2 ab | 28.8 ± 0.9 ab | 12.8 ± 0.8 a |
| winter and summer | 6.1 ± 0.1 c | 44 ± 2 ab | 26.4 ± 0.8 b | 11.3 ± 0.3 a | |
| French axis | winter | 7.2 ± 0.1 a | 39 ± 2 b | 32.1 ± 2.0 a | 12.4 ± 0.3 a |
| winter and summer | 6.9 ± 0.1 ab | 39 ± 2 b | 29.3 ± 1.4 ab | 11.4 ± 0.4 a | |
| Ballerina | winter | 6.5 ± 0.1 bc | 43 ± 1 ab | 25.0 ± 1.6 b | 10.7 ± 0.7 ab |
| winter and summer | 5.8 ± 0.2 c | 50 ± 5 a | 17.3 ± 0.8 c | 8.6 ± 1.0 b | |
Figure 2.
Average growth of stem diameter (A), number of shoots (B), shoot length (C) and total shoot length (D) of apple trees in 2019–2022 depending on the crown shape and pruning time
Note: cultivars: ‘Fuji’ (F), ‘Honeycrisp’ (HC); crown form: slender spindle (SS), French axis (FA), ballerina (B); pruning period: winter (W), winter and summer (WS)
Table 3.
Specific productivity of apple trees depending on the shape of the crown and the term of pruning (averaged data for 2019–2022 years)
| Crown form | Term of pruning | Specific productivity per bole cross-sectional area (kg·cm−2) | Specific productivity per total shoot length (kg·m−1) |
|---|---|---|---|
| ‘Fuji’ | |||
| Slender spindle | winter (control) | 0.40 ± 0.03 cd | 0.95 ± 0.06 c |
| winter and summer | 0.51 ± 0.04 bc | 1.44 ± 0.13 b | |
| French axis | winter | 0.26 ± 0.02 e | 0.72 ± 0.10 c |
| winter and summer | 0.33 ± 0.01 de | 0.79 ± 0.12 c | |
| Ballerina | winter | 0.57 ± 0.05 ab | 1.42 ± 0.09 b |
| winter and summer | 0.68 ± 0.04 a | 2.03 ± 0.19 a | |
| ‘Honeycrisp’ | |||
| Slender spindle | winter | 0.31 ± 0.03 bc | 0.84 ± 0.05 bc |
| winter and summer | 0.40 ± 0.03 ab | 1.18 ± 0.04 ab | |
| French axis | winter | 0.17 ± 0.02 d | 0.54 ± 0.08 c |
| winter and summer | 0.24 ± 0.01 cd | 0.75 ± 0.08 bc | |
| Ballerina | winter | 0.35 ± 0.03 ab | 1.13 ± 0.07 b |
| winter and summer | 0.43 ± 0.05 a | 1.78 ± 0.24 a | |
[i] The average values (mean ± SD) of indicators marked with the same letter do not differ according to the Tukey test (p = 0.05); The analysis was performed for each cultivar separately
Figure. 3.
Averaged data of specific productivity per cross-sectional area of the stem (A) and specific productivity per total shoot length (B) of apple trees for 2019–2022 depending on the shape of the crown and the term of pruning
Note: see Fig. 1