Strawberries are highly susceptible to bruising and post-harvest decay and low levels of calcium exacerbate the problem, reducing shelf life. Calcium helps improve fruit firmness, prolongs keeping quality and extends shelf life.
While most calcium is found in the leaves, petioles, crown and roots, the small amount that does get into the fruit is critical in terms of berry structure and shelf life.
![Macronutrient partitioning in strawberries]()
Although the inner fruit and distal parts of the fruit contain little calcium, the relatively high concentrations found in the fruit margins are particularly important in terms of fruit quality.
![Nutrient distribution in strawberries]()
Trials show that calcium increases fruit firmness and prolongs keeping quality.
![Calcium content correlated with strawberry shelf life]()
![Effect of calcium on fruit firmness and shelf life]()
![Effect of foliar calcium on fruit firmness]()
However, excessive rates of calcium at the expense of other cations can reduce fruit firmness and shelf life. For this reason it is important to keep calcium applications in balance with other cations such as potassium and magnesium.
![Effect of cation ratios on calcium deficiency]()
Calcium also helps to reduce levels of mold on fruit post-harvest. This calcium can also be applied pre-harvest as a foliar application.
![Effect of foliar calcium on fruit firmness and disease incidence]()
Ca reduces albinism, maintaining fruit coloration through increasing anthocyanin levels during maturity.
![Effect of foliar calcium on fruit firmness and disease incidence]()
Silicon increases fruit firmness
Silicon also has an effect on fruit quality, through improving firmness and there are indications that can also improve disease tolerance. Applications of silicon can improve shelf life. The key benefit of silicon in this respect is its role in reinforcing the cell wall.
![Effect of silicon on strawberry fruit firmness]()