This document discusses nutrient deficiency in plants. It identifies the different types of environmental stress factors plants can experience, including biotic and abiotic factors with nutrient stresses falling under abiotic factors. It also outlines the general effects of different available nutrient concentrations in the soil and lists the conditions that can lead to nutrient deficiency stress in plants. Finally, it provides details on the macronutrients and micronutrients essential for plant growth as well as symptoms of deficiency for specific nutrients like nitrogen, phosphorus, and potassium.

1. Nutrient Deficiency in Plants
Environmental stress factors
 Types of environmental factors
 Biotic
 Abiotic
Nutrient stresses come under abiotic factor
Stress reactions resulting from sub-optimal and damaging quantities.
Nutrient Stress deviation from the normal physiological processes as a result of sub-
optimal or toxic concentrations of nutrition.
Environmental noxae: stress factors which trigger stress reactions when applied in any
concentration, e.g. UV-B, Ozone, ionizing radiations, heavy metals, aluminum etc.
Specific and un-specific reactions to stress: un-specific reactions include e.g. modification of
basic metabolism. Specific reactions include e.g. the production of heat shock
proteins.
Currently 15-17 elements are known to be essential for plant growth, but the role
in the physiological metabolism is not known in detail for all of them.
General effects of available nutrient concentration
The different ranges can be:
a) Extreme deficiency range
b) Severe deficiency range
c) Moderate deficiency range
d) Luxury range
e) Toxic range
Critical concentration range: it occurs between deficiency and luxury consumption. This
information is useful for the measurement of the degree of stress in a plant.
Conditions for nutrient deficiency stress
a) Amount and concentration of nutrients in the soil.

2. b) Form of the soil.
c) The contents of the soil solutions.
d) Soil pH.
Nutrient concentration in plants:
These vary with
a) Plant age
b) Plant part
c) Plant species
d) Soil type
Deficiency symptoms
Symptom: is any perceptible change in known structure, appearance or function.
These include:
 Yellowing (chlorosis)
 Death (necrosis)
 Lesions
 Malformations
 Malfunctions
 Reduced growth and yield
Confusion: Occurs when one realizes that similar symptoms can be seen by
a) Toxic levels of nutrients
b) Pathogenic organisms
c) Air pollutants
d) Pesticides
Symptoms may vary with plant species or variety.
Important Point to remember for Stress diagnosis: Yield or growth rate is usually
impaired before other symptoms of deficiency occur so that some other indications

3. of at least the potential for a deficiency must be considered in any diagnosis
procedure.
Important Definitions
 An element is a pure chemical that contains only one type of atom.
 A compound is a molecule that contains one or more elements.
Essential Elements
 The 16 elements required by plants are obtained from the soil, water and air.
 Thirteen of these elements must be supplied by the soil.
 Six of the soil elements required by plants are needed in relatively large
amounts and are usually added to the soil through fertilizer or lime. These
are called macronutrients.
 The remaining 7 elements supplied by soil are required in very small
amounts and are termed micronutrients.
Macronutrients
 Macronutrients are needed in relatively large amounts by plants.
Macronutrients – Form Used By Plants

4. Micronutrients
 Macronutrients are needed in relatively small amounts by plants.
 They are usually supplied by fertilizers.
Micronutrients – Form Used By Plants

5. Nutrient Deficiency Symptoms
 Nutrient deficiency symptoms usually appear on the plant when one or more
nutrients are in short supply.
 In many cases, deficiency may occur because an added nutrient is not in the
form the plant can use.
 Deficiency symptoms for specific elements are included on the "Key to
Nutrient Disorders".
Nutrient Deficiencies
 Every soil is not susceptible to the same nutrient deficiencies.
 For example, coarse-textured soils low in organic matter is susceptible to
sulfur deficiencies whereas sulfur is usually in adequate supply in clayey
soils or soils high in organic matter.
Macronutrient Deficiencies & Soils

6. Micronutrient Deficiencies & Soils
Deficiency Symptoms – N
 General chlorosis.
 Chlorosis progresses from light green to yellow.
 Entire plant becomes yellow under prolonged stress.
 Growth is immediately restricted and plants soon become spindly and drop
older leaves.
Deficiency Symptoms – P
 Leaves appear dull, dark green, blue green, or red-purple, especially on the
underside, and especially at the midrib and vein.

7.  Petioles may also exhibit purpling. Restriction in growth may be noticed.
Deficiency Symptoms – K
 Leaf margins tanned, scorched, or have necrotic spots (may be small black
spots which later coalesce).
 Margins become brown and cup downward.
 Growth is restricted and die back may occur.
 Mild symptoms appear first on recently matured leaves.
Deficiency Symptoms – Ca
 Growing points usually damaged or dead (die back).
 Margins of leaves developing from the growing point are first to turn brown.
Deficiency Symptoms – Mg
 Marginal chlorosis or chlorotic blotches which later merge.
 Leaves show yellow chlorotic interveinal tissue on some species, reddish
purple progressing to necrosis on others.
 Younger leaves affected with continued stress.
 Chlorotic areas may become necrotic, brittle, and curl upward.
 Symptoms usually occur late in the growing season.
Deficiency Symptoms – S
 Leaves uniformly light green, followed by yellowing and poor spindly growth.
 Uniform chlorosis does not occur
Deficiency Symptoms – Cu
 Leaves wilt, become chlorotic, then necrotic.
 Wilting and necrosis are not dominant symptoms.
Deficiency Symptoms – Fe
 Distinct yellow or white areas appear between veins, and veins eventually
become chlorotic.
 Symptoms are rare on mature leaves.
Deficiency Symptoms – Mn

8.  Chlorosis is less marked near veins.
 Some mottling occurs in interveinal areas.
 Chlorotic areas eventually become brown, transparent, or necrotic.
 Symptoms may appear later on older leaves.
Deficiency Symptoms – Zn
 Leaves may be abnormally small and necrotic.
 Internodes are shortened.
Deficiency Symptoms – B
 Young, expanding leaves may be necrotic or distorted followed by death of
growing points.
 Internodes may be short, especially at shoot terminals.
 Stems may be rough, cracked, or split along the vascular bundles.
Crops Highly Susceptible to Deficiencies