Preventing a Calcium Deficiency In Plants

Calcium Deficiency in Plants

Calcium plays a critical role in building cell wall structure. Since cell walls surround every cell, calcium is vital for maintaining cellular integrity. It is also a part of many enzymes crucial for cell growth and development and assists in transporting substances across cell membranes. 

Calcium deficiencies often appear in meristematic cells (dividing cells) and typically manifest in growing roots, shoots, buds, and young leaves. Symptoms include downward hooking of leaves, marginal necrosis, and short, stubby roots.

 

Symptoms of Calcium Deficiency

Calcium deficiency symptoms are sometimes mistaken for pathological rot. These symptoms usually start as localized tissue necrosis leading to stunted growth, necrotic leaf margins, curling leaves, and death of terminal buds and root tips.

Other signs can be premature flower drop, yellow leaf margins, and distorted new growth. In rapidly growing plants, like certain orchids, new growth may turn black and undergo necrosis.

Many growers have been unsuccessful at trying stop rots using bactericides, fungicides, sterilising compounds. Much too their woes, the rot continues to spread, not realising that the lack of calcium has caused cells to die (necrosis) presenting signs that appear to be rot.

Very often leaf surfaces will develop black necrotic spots and this could be the first indication of a calcium deficiency.

 

Calcium Mobility in Plants

Calcium is absorbed through growing root tips and transported to developing cells via the xylem vessels from where it is used incorporated into various cell structures.

Once calcium is taken up by the developing cells it becomes immobile. Unlike other nutrients that can be translocated from one part of a plant to another, calcium is immobile, it cannot be translocated.

This means that when a cell is deficient in calcium it cannot be replaced. This what contributes to cells dying and form black/brown coloured spots (lesions).

 

Correcting Calcium Deficiency

Alternatives include using fertilizers that contain calcium. Many fertilisers formulated to exclude calcium. If the fertiliser you are using does not contain calcium consider using Superthrive (Dyna Gro) Nutrient Solution as your preferred fertiliser of choice. All Superthrive Nutrient Solutions are formulated to include calcium.

A solution of calcium nitrate can be applied as well. Many orchid growers have reported that a monthly application of calcium nitrate has eliminated their 'rotting' problems.

This approach ensures that plants receive calcium with every application of the fertilizer, eliminating the need for separate calcium supplementation. 

Other sources of calcium can to used such as powdered shell or lime which can be incorporated into the potting  or applied to the potting mix surface and and watered in.

Regular calcium supplementation, especially during active growth (cell formation), is essential to prevent cell necrosis.

 

Comparison of Fertilizers

Below is a chart comparing some commonly available fertilisers to Superthrive(Dyna-Gro). Note that they do not have calcium in their formulations, while Superthrive (Dyna-Gro) does.