Albino Strawberries: Why Does the Fruit Stay White?

Pale or almost white fruit in a normally red strawberry cultivar can reflect a physiological disorder described as albinism or white fruit disorder. It is not the same as the inherited colour of a naturally white cultivar, and pale colour alone does not establish the cause.

Affected fruit can be softer, less flavourful and more vulnerable to damage. Research has associated the disorder with calcium status, nutrient balance, vegetative growth and environmental conditions. These relationships make it a useful example of why nutrient supply and delivery to a particular organ need to be distinguished.

Calcium must reach the developing tissue

Calcium helps stabilise membranes and cross-link pectins in cell walls, contributing to tissue integrity and fruit firmness. Measuring calcium in the root-zone solution therefore answers only part of the nutritional question: the element must also reach the tissue where it is needed.

Calcium moves predominantly through the xylem with water and is relatively poorly redistributed through the phloem. As strawberry fruit develops, declining xylem functionality can restrict later delivery through the fruit stalk. Adequate supply around roots does not necessarily establish adequate fruit calcium.

The wider distinction between nutrient availability and acquisition is discussed in More Fertilizer, Less Uptake? The Roots Decide. Transport within the plant adds another level beyond root uptake.

Calcium status is associated with albinism

Comparisons of normally coloured and albino strawberries reported lower calcium and higher potassium in affected fruit, alongside higher K:Ca and N:Ca ratios. These associations do not demonstrate that low calcium alone causes the disorder.

A recent review describes albinism as multifactorial, with excessive vegetative growth, nutrition, environmental conditions and impaired calcium transport among the relevant factors. Calcium is therefore part of the physiological explanation, not a diagnosis that follows automatically from white fruit.

Fruit quality and direct calcium delivery

Research on water soaking, a distinct disorder involving translucent, softened tissues, also illustrates the importance of calcium delivery. Experiments reported reduced water soaking, cuticular microcracking and membrane leakage following calcium treatment, consistent with roles in tissue integrity.

More recent work examined uptake directly through the strawberry fruit surface. Calcium sprays increased fruit calcium and reduced susceptibility to water soaking under the tested conditions. These findings should not be treated as proof that the same treatment prevents albinism: the disorders and measured outcomes differ.

Silicon–calcium interactions vary

Silicon and calcium are often considered together because both can influence tissue structure, although calcium is essential while silicon is generally discussed in terms of conditional benefits. The distinction is outlined in Essential and Beneficial Elements: What Do Plants Actually Need?

Experiments across several plant species have reported increased calcium acquisition or transport towards shoots after silicon treatment. Short-term work in rice also reported a dose-dependent increase in uptake measured using radioactive ⁴⁵Ca. Other studies have found no increase or reduced calcium accumulation.

The interaction therefore depends on species, silicon dose, nutritional status and environment. These findings do not establish that silicon invariably increases calcium uptake, or that a response in shoots predicts fruit composition. Broader evidence is considered in Silicon in Plants: Food, Biostimulant or Structural Tool?

Leaf calcium is not fruit calcium

Osei and colleagues (2023) examined silicic acid, potassium bicarbonate and their combination in strawberry cultivars ‘Festival’ and ‘Fortuna’, grown with a cooled root zone. They measured nutrient concentrations in leaves, roots and crowns before the plants entered the reproductive phase. This was not a comparison of full and deficit irrigation, and it did not measure calcium delivery to fruit.

The highest mean leaf calcium concentration in ‘Festival’ occurred after root application of silicic acid, while in ‘Fortuna’ it occurred after foliar application of the silicic-acid–bicarbonate combination. However, neither mean was significantly higher than its cultivar's untreated control in the reported multiple comparisons. The numerical differences therefore do not establish an increase over the control. Tissue concentration also does not directly measure the rate of calcium uptake or transport.

Leaves and fruit differ in their transpiration and transport characteristics. A response in one organ cannot be assumed to occur in another, even within the same plant. These results do not demonstrate increased fruit calcium or prevention of albinism.

Interpreting an older report of white fruit

An older report linked soluble silicon fertilisation with albino strawberry fruit. Later work did not reproduce the problem. In their 2017 study of silicon uptake and amendments in strawberry, Ouellette and colleagues reported no harmful fruit effect and proposed that inappropriate mixing into the nutrient solution could explain the earlier observation.

That is an interpretation of the discrepancy, not proof of the cause of the older result. Formulation, mixing chemistry and the wider nutrient programme need to be considered before attributing an outcome to silicon alone.

Nutrient balance and water movement

The higher potassium relative to calcium reported in albino fruit points to nutrient balance rather than an isolated calcium concentration. Calcium, potassium and magnesium can influence one another's acquisition and distribution, while water movement, root function and tissue development also affect delivery.

Adding calcium may therefore leave a transport limitation or another contributing factor unresolved. Equally, a nutrient ratio associated with affected fruit is not by itself a validated target ratio for correcting the disorder.

What can be concluded about silicon and albinism?

The evidence connects calcium status with albinism and supports calcium's structural roles in fruit quality. Silicon can influence calcium acquisition or distribution in some plant species, but strawberry tissue responses need to be interpreted in relation to the treatment, cultivar and statistical comparison.

These observations do not establish the complete sequence from silicon application to increased fruit calcium and prevention of albinism. Each step requires suitable evidence rather than inference from a leaf response or another species.

For growers, the broader lesson is to consider supply, root uptake, transport to the target organ, nutrient balance and growing conditions together. A visible symptom does not establish that one additional element will correct it.

Exploring silicon in practice

For composition and application guidance, see Ortho Origin. The studies discussed here do not demonstrate that this finished product increases calcium in strawberry fruit or prevents albinism. Follow the label rather than assuming that a higher dose improves the result.

References

Sharma, R.R., Krishna, H., Patel, V.B., Dahuja, A. & Singh, R. (2006). Fruit calcium content and lipoxygenase activity in relation to albinism disorder in strawberry. Scientia Horticulturae, 107, 150–154. https://doi.org/10.1016/j.scienta.2005.06.008.

Lieten, F. & Marcelle, R.D. (1993). Relationships between fruit mineral content and the “albinism” disorder in strawberry. Annals of Applied Biology, 123, 433–439. https://doi.org/10.1111/j.1744-7348.1993.tb04105.x.

Hurtado, G. & Knoche, M. (2026). A review of surface disorders in strawberry: insights and challenges. Frontiers in Horticulture, 5, 1779354. https://doi.org/10.3389/fhort.2026.1779354.

Hurtado, G. et al. (2025). Pathways and factors in calcium uptake through the skins of strawberry fruit. Scientific Reports, 15, 29840. https://doi.org/10.1038/s41598-025-15749-4.

Greger, M. et al. (2018). Silicon Influences Soil Availability and Accumulation of Mineral Nutrients in Various Plant Species. Plants, 7(2), 41. https://doi.org/10.3390/plants7020041.

Pavlovic, J. et al. (2021). Interactions of Silicon With Essential and Beneficial Elements in Plants. Frontiers in Plant Science, 12, 697592. https://doi.org/10.3389/fpls.2021.697592.

Jang, S.-W. et al. (2018). Exogenous short-term silicon application regulates macro-nutrients, endogenous phytohormones, and protein expression in Oryza sativa L. BMC Plant Biology, 18. https://doi.org/10.1186/s12870-017-1216-y.

Ouellette, S. et al. (2017). Silicon Transporters and Effects of Silicon Amendments in Strawberry under High Tunnel and Field Conditions. Frontiers in Plant Science, 8, 949. https://doi.org/10.3389/fpls.2017.00949.

Osei, A.F., Jin, X., Abdullah, W.Z.B.W. & Sidique, S.N.M. (2023). Silicon improves strawberry plants nutrient uptake and epicuticular wax formation in a rhizosphere cooling system. Asian Journal of Agriculture and Biology, 2023(2), 2022060. https://doi.org/10.35495/ajab.2022.060.