SILARA N30 / Evaluation pathway / Updated 24 September 2026
What research in ‘Hayward’ kiwifruit tells us about orthosilicic acid, firmness and ripening, with the complete published article available to read and download.
Published research is a basis for evaluation. This study tested orthosilicic acid on kiwifruit from a Greek orchard. It did not test SILARA N30 or establish a SILARA N30 orchard rate, fruit dip or commercial storage outcome.
Bio Charge summary: 2 pages. Original published paper: 18 pages · 5.4 MB · Open access, CC BY 4.0.
01 / Skodra and colleagues
Firmness and weight loss: the clearest findings
Skodra, C., Michailidis, M., Raptis, P., Giannoutsou, E., Adamakis, I.-D.S., Kontomina, E.-A., Samiotaki, M., Bazakos, C., Tanou, G. & Molassiotis, A. (2026). Silicon-induced tissue-specific reprogramming of the ripening transition in kiwifruit. Postharvest Biology and Technology 232, 113983. DOI: 10.1016/j.postharvbio.2025.113983.
Publication date clarified: the article first appeared online on 10 October 2025 and belongs to the February 2026 journal volume. It is the same paper previously described as recent 2025 research.
The experiment compared foliar applications, postharvest dipping, their combination and a no-silicon control. Fruit were assessed after 80 days at 0°C and again after seven days of ripening at 20°C. All three silicon treatments maintained higher firmness in the flesh (pericarp) and core (placenta), and reduced weight loss at both assessments.
| Measure | After 80 days of cold storage | After seven more days of ripening |
|---|---|---|
| Flesh and core firmness | Higher with all three Si treatments | Higher with all three Si treatments |
| Weight loss | Lower with all three Si treatments | Lower with all three Si treatments |
| Ethylene production | No significant treatment differences shown | Lower with all three Si treatments |
| Respiration rate | No significant treatment differences shown | Lower with foliar and combined treatments; dipping alone was not significantly different from control |
Comparisons are with control. Figure 1 uses different letters for significant differences under Duncan’s multiple range test (p ≤ 0.05). Treatments sharing a letter are not significantly different. These are qualitative comparisons; percentage improvements have not been estimated from the plotted bars.
Respiration and ethylene need qualification. Section 3.1 says these were lower at both stages, but Figure 1C labels all cold-stage groups “a”, indicating no significant cold-stage differences. At ripening, the dipping-only respiration group is “ab” and shares “a” with control. The summary follows the figure’s statistical comparisons rather than implying a uniform response at every stage.
The authors report no effect on soluble solids concentration or titratable acidity. Delayed softening is therefore not evidence that every quality measure improved, nor does this experiment quantify an additional number of saleable storage days.
02 / What was actually tested
Five orchard sprays, a fruit dip, and a combination
The experiment used 12-year-old ‘Hayward’ vines in one commercial orchard in Pieria, northern Greece. Six vines received silicon sprays and six were controls. The silicon source was orthosilicic acid supplied by Agrology SA.
Preharvest foliar treatment
Five applications of 5 mg/L orthosilicic acid (52 µM), at 12, 24, 48, 82 and 125 days after full bloom. Fruit were harvested at commercial maturity, 150 days after full bloom.
Postharvest treatment
A 20-minute immersion in 20 mg/L orthosilicic acid (208 µM), compared with a sterile deionized-water dip. Fruit from sprayed and control vines were split to form the four groups below.
| Group | Foliar silicon | Postharvest dip |
|---|---|---|
| Control | None | Water |
| Foliar only | Five applications at 5 mg/L | Water |
| Dipping only | None | 20 mg/L for 20 minutes |
| Foliar + dipping | Five applications at 5 mg/L | 20 mg/L for 20 minutes |
All fruit were stored at 0°C and 95% relative humidity for 80 days, followed by seven days at 20°C. Firmness, respiration and ethylene measurements used three replicates of four fruit per treatment; weight loss used three replicates of six fruit. These measurement samples are smaller than the 250 fruit allocated to each group.
Methods 2.1 initially describes the control vines as unsprayed, then describes water foliar application in the group definitions. The distinction does not change which groups received silicon, but the exact foliar-control procedure would need clarification when reproducing the experiment.
Study concentrations are not SILARA N30 rates. The reported mg/L values refer to orthosilicic acid as stated in Methods 2.1. They should not be read as elemental-silicon or SiO₂ mass rates per hectare, and cannot be converted into a SILARA N30 programme from this paper.
03 / Biological interpretation
Tissue-specific changes help explain the response
Silicon accumulated especially near the fruit-pedicel junction and core. The authors examined changes in cell-wall components, sugars, organic acids, polyphenols, genes and proteins. The findings suggest several routes through which the tested treatments could influence ripening.
The combined foliar-and-dipping treatment was used for detailed molecular analyses. A comparison with an earlier calcium dataset identified some overlapping responses; it was not a trial proving a combined silicon-and-calcium tank mix or synergy for SILARA N30.
These observations help frame further research. They do not establish that an amorphous colloidal silica product will have the same uptake, biological effects or commercial benefits as the soluble orthosilicic acid used here.
04 / Evaluation pathway
What a SILARA N30 kiwifruit programme still needs
SILARA N30 requires its own replicated, crop-specific evaluation under New Zealand conditions. Orchard foliar use and postharvest dipping are distinct applications; this paper validates neither for SILARA N30.
- Establish crop safety, application rate, timing and compatibility for the intended cultivar and programme.
- Compare treated and untreated fruit using a defined cold-storage and ripening programme, recording firmness, weight loss, disorders, eating quality and packout.
- Repeat across orchards and seasons before making claims about extra storage days or commercial returns.
The evidence concerns ‘Hayward’ and should not be assumed to transfer to other kiwifruit cultivars or to SILARA N30. Confirm the intended use and current product directions with Bio Charge before planning a trial.
Read the complete article
The full 18-page published paper is available below. The Shopify-hosted PDF is an unchanged copy of the supplied publication, including its authorship, figures, references and licence statement. Supplementary files are available separately through the publisher.
© The authors 2025. Published by Elsevier B.V. under Creative Commons Attribution 4.0 (CC BY 4.0). Original article unchanged; this Bio Charge page and its brief are summaries and adaptations. No author or publisher endorsement of SILARA N30 is implied.