Table 14.
Seasonal changes of the calcium leaf status under the influence of different potassium fertilization rates and fertigation approaches in 2017, % d.m.
| Control N20P15K0 |
N20P15K25 | N20P15K35 | N20P15K45 | N20P15K30 | N20P15K40 | N20P15K50 | HCP05 | |
|---|---|---|---|---|---|---|---|---|
| G1 (unchangeable K rates) | G2 (season adjusted K rates) | |||||||
| cv. “Zhigulevskoye” | ||||||||
| 30.05. | 1.34 | 1.36 | 1.32 | 1.36 | 1.35 | 1.34 | 1.30 | 0.07 |
| 30.06. | 1.70 | 1.36 | 1.48 | 1.44 | 1.38 | 1.34 | 1.24 | 0.08 |
| 27.07. | 1.57 | 1.65 | 1.55 | 1.24 | 1.27 | 1.26 | 1.22 | 0.08 |
| 30.08. | 1.28 | 1.20 | 1.18 | 1.24 | 1.19 | 1.17 | 1.26 | 0.08 |
| 28.09. | 1.59 | 1.59 | 1.71 | 1.52 | 1.65 | 1.66 | 1.54 | 0.09 |
| cv. “Lobo” | ||||||||
| 30.05. | 1.23 | 1.19 | 1.25 | 1.21 | 1.23 | 1.24 | 1.18 | 0.05 |
| 30.06. | 1.47 | 1.44 | 1.51 | 1.66 | 1.45 | 1.48 | 1.30 | 0.08 |
| 27.07. | 1.25 | 1.22 | 1.27 | 1.19 | 1.24 | 1.24 | 1.21 | 0.08 |
| 30.08. | 1.15 | 1.02 | 1.07 | 1.00 | 1.06 | 1.09 | 1.03 | 0.07 |
| 28.09. | 1.26 | 1.25 | 1.22 | 1.19 | 1.24 | 1.32 | 1.30 | 0.07 |