Calcium Formate as a New Leaf Fertilizer for Apples - Effect of Treatment Timing and Intensity on Calcium Content and Quality Parameters
In 2004 a trial using calcium formate (in a 45 % suspension; now available on the market in a fixed formula under the brand name Folanx® Ca29) was carried out at the OVA (Fruit Research and Extension Centre) in Jork-Moorende. The objective was to test whether calcium formate can be used as a leaf fertilizer for apples instead of the standard calcium chloride (CaCl2) and calcium nitrate (Ca(NO3)2) treatments.
Trial Design
A liquid calcium formate formula (containing 45 % pure calcium formate) was tested and compared to both an untreated control group and a conventional leaf fertilizer containing calcium chloride/calcium nitrate (standard recommendation for the Niederelbe region).
The 5 test groups were treated according to the following plan:
A liquid calcium formate formula (containing 45 % pure calcium formate) was tested and compared to both an untreated control group and a conventional leaf fertilizer containing calcium chloride/calcium nitrate (standard recommendation for the Niederelbe region).
The 5 test groups were treated according to the following plan:
| Treatment Plan OVA Jork Trial 2004 | ||
| Group | 4 Treatments up to the June Fruit Drop (approx. every 14 days) |
4 Treatments up to Harvesting |
| Control (negative control) |
- |
- |
| CaCl |
- |
x |
| CaFo 4 x prior to harvesting | - |
x |
| CaFo 4 x prior to the June fruit drop and 4 x prior to harvesting | x |
x |
| CaFo 4 x prior to the June fruit drop and 4 x prior to harvesting (double concentration) | xx |
xx |
Treatment Intensity:
x: 2.5 kg per ha and per meter canopy height
xx: 5.0 kg per ha and per meter canopy height (= double concentration)
x: 2.5 kg per ha and per meter canopy height
xx: 5.0 kg per ha and per meter canopy height (= double concentration)
The trials were carried out using the Braeburn variety. After the June fruit drop the amount of fruit was reduced to around 20 fruits per tree. Each test plot consisted of 10 trees of which 9 were evaluated.
Immediately after harvesting on 13.10.2004 the apples were examined for the following parameters:
After cold-storage at 3° C the following parameters were assessed on 24.02.2005:
- Size of the fruit, weight of the fruit, overall color
- Ca level (mg Ca/100 g fm)
After cold-storage at 3° C the following parameters were assessed on 24.02.2005:
- Emergence of bitter pits (%)
- Emergence of skin browning (%)
- Emergence of lenticel marking (%)
Results and Conclusions
The results are illustrated in the following diagrams.
The results are illustrated in the following diagrams.
The results show that not only could the calcium levels in the apples be increased through the calcium treatments but that it was also possible to reduce the occurrence of physiological disorders, i.e. bitter pits, skin browning and lenticel marking.
Compared to the standard CaCl2 + Ca(NO3)2 variant, the effectiveness of the calcium formate treatment was significantly better - the best effect being achieved through early calcium formate spraying following blooming.
Despite there being no further rise in fruit calcium levels, doubling the calcium concentration to 5.0 kg per ha and per meter canopy height showed a tendency to further reduce the occurrence of physiological disorders. This dosage corresponds to the current usage level recommended for the Folanx® Ca29 product.
There were no plant tolerance issues in connection with the calcium formate treatment. We can, therefore, recommend implementing it very early on - right after the blooming period.
After the June fruit drop calcium formate is an obvious alternative to using calcium nitrate due to the better results it achieves. Once August comes round it can also be used instead of calcium chloride as the then prevailing weather conditions, e.g. high temperatures, do not favor calcium chloride usage.
Compared to the standard CaCl
Despite there being no further rise in fruit calcium levels, doubling the calcium concentration to 5.0 kg per ha and per meter canopy height showed a tendency to further reduce the occurrence of physiological disorders. This dosage corresponds to the current usage level recommended for the Folanx
There were no plant tolerance issues in connection with the calcium formate treatment. We can, therefore, recommend implementing it very early on - right after the blooming period.
After the June fruit drop calcium formate is an obvious alternative to using calcium nitrate due to the better results it achieves. Once August comes round it can also be used instead of calcium chloride as the then prevailing weather conditions, e.g. high temperatures, do not favor calcium chloride usage.
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