Calcium deficiency – stress symptom?

Calcium is often used as a ‘stress buster’, but calcium is better used to fix stress symptoms rather than as a cure for stress. Here we discuss the relationship between stress and calcium in plants, and we can use this understanding to better treat both stress and reduce calcium deficiency.

Plants lose calcium from cell walls when they are experiencing ‘stress’ from sub-optimal growing conditions such as high or low temperatures, drought, or high UV. During stress plants produce ethylene, a hormone that encourages movement of calcium from cell walls into the interior of cells. Here calcium is used by the plant as a ‘second messenger’ whereby it triggers production of stress protectant compounds and processes in the plant.

When stressed plants produce elevated levels of peroxide, which transforms into damaging ROS such as superoxide.

When stressed plants produce ethylene which removes calcium from cell walls and intercellular glues.

This is an important process for helping plants cope with stress, but it has the negative effect of depleting calcium from cell walls – leading to increased levels of calcium deficiency, disease incidence, and physiological disorders (bitter pit, blossom end rot, tip burn etc) following stress periods.

How best to manage calcium during stress?

Excess early calcium applications are no use for preventing calcium problems during stress later in the season.

Plant cells do not store more calcium than they need in cell walls (they have no storage capacity for luxury levels of Ca). This means that it is not possible to apply excess calcium ahead of stress in order to prevent physiological disorders, loss of quality and to hedge against problems later on.

Applying calcium to top up lost calcium after stress periods is difficult, as the parts of crops we are targeting are often ones that have an inherently low ability to absorb calcium.

Mature fruits and leaves have a lower ability to absorb applied calcium than younger ones which means topping up calcium following stress can be very inefficient.

While stress is ongoing calcium will continue to be lost from cell walls, and even after the cessation of stress plants take a while to re-adjust their production of ethylene.

Until the stress is under control and the plants ethylene production is reset, any reapplied calcium will continue to be removed from cell walls by the crop.

The best approach to using calcium during stress is to take a two pronged approach – fix the stress, and then apply small amounts of calcium in a formula that can be properly absorbed.

The primary way to prevent calcium problems during stress, is to reduce calcium loss during poor growing conditions.

Indra is Levity’s anti-stress product, it works by promoting production of polyamines and anti-oxidants in plants. Polyamines occupy the same sites as calcium in cell walls, and can strengthen them. Polyamines and ethylene share the same chemical precursor, plant cells can not make both ethylene and polyamines at the same time.

By promoting polyamine production, Indra helps reduce ethylene production – safeguarding cell wall calcium levels.

Indra also helps plants make anthocyanins, poweful antioxidants that help protect the plant from stress damage. Regular applications of Indra during periods of stress helps plants retain calcium.

Indra stimulates polyamine and antioxidant production, protecting against the major effects of plant stress.

Once a crop has been safeguarded against calcium loss during stress, keeping good calcium and preventing physiological disorders becomes more easy. Small amounts of calcium applied at key timings should then be sufficient to maintain good fruit quality.

Any calcium applied must be in a formulation that the crop can absorb. Because calcium absorption is closely linked to auxin content in plant tissue, the ability to absorb calcium is highly variable in different parts of plants. Often the part of the crop being targeted (fruit, tubers, flowers, aged leaves) are inherently less able to absorb applied calcium.

Calcium absorption is linked to polar auxin transport, low auxin areas of plants can not effectively absorb applied calcium.

Auxins are not evenly distributed, so parts of plants like flowers, fruit and roots are inherently less able to take in calcium than folage.

It is far better to apply a small amount of easily absorbed calcium fertiliser, than a larger amount of conventional calcium fertiliser.

Albina uses Levity’s LoCal chemistry, which helps parts of plants with a low affinity for calcium absorption properly take up calcium. Albina is ideal for topping up calcium levels in crops that have encountered stress, as the calcium in Albina can be taken up properly by fruit and flowers. It only needs small doses as it is more efficient.

Albina contains LoCal chemistry, helping low auxin cells properly take in calcium even during stress.

Albina enables topping up of calcium in hard to treat parts of crops, it only requires low rates to be effective.


To safeguard against calcium depletion apply Indra at 1L/Ha whenever stress is present.

To top calcium up in fruit, flowers, roots or aged leaves use Albina at 1L/Ha.

This dual strategy is more effective than using high volumes of basic calcium fertilisers indiscriminately through a season.Β 

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Award winning scientist and experienced agronomist. With multiple patents, and proven track record of product development in biostimulants, pesticides and fertilisers.

David Marks

Managing Director, Linkedin Profile