Nutritient deficiency in plants: Signs to watch out for

12.09.18 01:40 AM Comment(s) By Admin

Apart from pest and disease attacks, plants can also suffer from nutrient deficiencies. In this blog, we cover deficiency symptoms of the main nutrients required by a plant. Any plant essentially needs '16' mineral nutrients to grow, live, and reproduce. A deficiency in any one of these nutrients would affect the plant's ability to complete its normal life cycle. Hence one needs to be cautious when feeding the plants.

Essential Plant Nutrients

Major Nutrients

Carbon (C), Oxygen (O), Hydrogen(H)

Macro Nutrients

Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Sulphur (S)

Micro Nutrients

Boron (B), Chlorine (Cl), Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo), Nickel (Ni), Zinc (Zn)

Symptoms and their interpretation

Plants have their mechanism to express nutrient requirements by showing "symptoms" of deficiency or toxicity (over-feeding). In a sense, this is a plant's voice or body language that can even reveal to us which mineral is deficient. Many a times, similar symptom may occur due to deficiency of more than one essential elements. In such a case, observing, if the symptom first appeared in newer leaves and shoots or the older ones, can help in identifying the true cause of deficiency. This happens because some of the elements are mobile, meaning they can move from one part of the plant to another whilst the others are immobile.

Mobile elements: N, P, K, Cl, Mg, Mo. If the mineral element is mobile, it's deficiency/toxicity appears in the older part of the plant first. This is because the nutrients travel from older leaves to the newer leaves where they are needed most.
Immobile elements: S, B, Fe, Zn, Ca, Cu, Mn, Ni. If the mineral element is immobile, the nutrients can not move from the older to the newer leaves. Therefore, deficiency symptoms appear in the growing region of the plant first.

Signs/Symptoms of Different Nutrient Deficiencies

Nitrogen (N)

Yellowing (chlorosis) of older leaves gradually progressing to the newer leaves, along with slow and stunted growth in plants. Nitrogen-deficient plants will mature early, but with lower quality and yield.

Phosphorus (P)

Leaves & stems of Phosphorus deficient plants are generally dark green. Older leaves turn yellowish with a pink/purplish margin.

Potassium (K)

Older leaves show chlorotic (yellowing) areas with burnt margins (scorch) along the edges of the leaves. It progresses along the leaf margin towards the base leaving the midrib alive and green.

Calcium (Ca)

Development of dark green leaves with leaf distortion. Leaf tips become brittle and dry and eventually wither and die.

Magnesium (Mg)

The most common symptom of Mg is inter-veinal chlorosis (yellowing of leaves in between the veins, yet veins remain green color) in younger leaves. Leaf margin becomes yellow or reddish-purple while the midribs remain green.

Sulphur (S)

Sulphur deficiency occurs in younger leaves first. Leaves turn green to yellow. Plants will be small and spindly in stature and stems are thin.

Iron (Fe)

Iron deficiency characterized by inter-veinal chlorosis with a sharp distinction between veins and yellowing areas of younger leaves. In cases of severe deficiency, leaves become whitish-yellow while the tissue becomes brown and dies (necrosis) leading to slow plant growth.

Manganese (Mn)

Manganese deficiency also causes inter-veinal chlorosis in young leaves, but there will be no sharp distinction lines existing between veins and yellowing areas, but rather a more diffuse chlorotic effect.

Boron (B)

Growing young leaves become yellow, and the terminal growing region dies. Additionally, we can see dark brown and irregular spots on the plants in case of severe deficiency.

Copper (Cu)

Plants show chlorosis of younger leaves with stunted plant growth. This deficiency causes tip burns in many vegetable crops. Ex: Tip burn in lettuce.

Zinc (Zn)

Inter-veinal chlorosis, especially midway between the leaf margin and midrib. Plants with Zinc deficiency experiences severely stunted growth as Zinc helps in elongation of internodes, which will be affected. At critical stages, plant tissue becomes grey-white and eventually dies.

Nickle (Ni)

Signs of chlorosis and inter-veinal chlorosis in young leaves leads to necrosis.

Chlorine (Cl)

Typical signs of chlorine insufficiency leads to wilting of leaves at the leaf margin and highly branched root system, especially in cereals. General signs like yellowing and dark brown patches with the demarcation between dead and live tissue.

Molybdenum (Mo)

Deficiency symptoms almost resemble Nitrogen deficiency symptoms showing chlorosis and stunted growth in plants. Other signs to look for may be scorching, cupping, or rolling of leaves. Molybdenum deficiency in cauliflower causes 'Whiptail' - a distinguished deficiency, wherein leaves become thick, brittle, and eventually wither, leaving only the midrib portion of leaf to remember the shape of 'tail.'

Do keep a lookout for these symptoms and give your plants proper care and maintenance.

Happy Gardening!