Nutrient

Table 1. Foliage plant malady symptoms and possible causal agents

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Plant part affected and symptoms

Chlorosis (general)

Low soil fertility Excessively high light intensity Excessively high temperatures

High Light intensity

High light intensity

Chlorosis (younger leaves)

Inadequate supply of iron or manganese and possibly copper or zinc Plants excluded from light for extended period phytotoxicity from pesticides

Iron

Manganese

Zinc

Chlorosis (older leaves)

Low nitrogen or potassium supply High soil salinity Over watering Poorly aerated soil mix

Nitrogen

Potassium

Marginal chlorosis

Low magnesium and potassium supply (primarily lower leaves) High soil salinity Cold drifts (primarily lower leaves) Spider mite feeding injury (primarily lower leaves) Phytotoxicity from pesticides

Magnesium

Interveinal chlorosis

Veinal chlorosis

Deficiency of iron or manganese (upper leaves affected first) Spider mite feeding injury Sulfur dioxide air pollution injury Phytotoxicity from pesticides

Injury from certain herbicides

Round chlorotic spots

Fungal or bacterial spots Phytotoxicity from pesticide, fertilizer or pollutant

Irregular, chlorotic spots

Cold – water injury Fungal or bacterial leaf spots Virus or virus like infection Phytotoxicity from pesticides, fertilizers, or pollutants.

Striped, chlorotic pattern not associated specifically with veins or interveinal areas

Feeding injury from spider mites, plant hoppers, leafhoppers, or trips

Mosaic, chlorotic pattern

Cold – water injury of some plants Virus or virus like infection Phtotoxicity from pesticides

Sectors of leaves that appear water soaked or have a greasy color

Early stages of high – temperature injury often associated with high light intensity or high temperatures which plants are subjected to when improperly handled during shipment.

Early stages of cold injury from either low air temperatures or very cold water dropping onto foliage

Certain foliar diseases caused bacterial or fungal pathogens

Foliar nematodes in fleshy tissue

Early stages of phytotoxicity from improper use of pesticides or fertilizers

Necrosis of leaf margin or tip

Nutrient deficiency: potassium (lower leaves first) Boron excess High soil salinity Fluoride phytotoxicity of susceptible plants High temperature injury Low temperature injury Desiccation injury Low relative humidity, particularly indoors Spider mite feeding injury Foliar bacterial diseases Phytotoxicity from pesticides or fertilizers.

Boron

Necrotic spots or sectors within the lamina

Cold – water injury Leaf miner feeding injury Leaf spot diseases fungal and bacterial Foliar nematode feeding injury Phytotoxicity from pesticides or fertilizers.

Leaf miner feeding injury

Combination of marginal and internal necrotic areas

Sun scorch Cold injury from low air temperatures or very cold water Foliar diseases and injury from several foliar feeding pests Air pollution injury Phytotoxicity from pesticides or fertilizers

Leaves abnormally large

Plants received a high level of nutrition Plants grown under moderate to low light intensity Stock plants not harvested frequently enough Old specimens with large root system

Low light intensity

Leaves abnormally small

Plants grown under low nutritional program Lack of copper, which occurs first in new leaves and may be associated with some chlorosis High soil Salinity Plants grown under excessively high light intensity Low light and low humidity.

Container-grown plants that become root-bound Root mealy bugs or nematodes Root diseases Phytotoxicity from certain pesticides Tarsonemid mite injury

Petiole (leaf stem too long

Petiole very short

Lamina (leaf blade long and narrow

Lamina short

lamina very thin

High nitrogen nutrition Low light intensity

Lamina extremely thick

Virus or virus like disease Phytotoxicity form pesticide s High light intensity Tarsonemid mites

Splitting of lamina along margins

Mechanical injury to developing or fully expanded leaves Fluctuating moisture supply

Mechanical injury

Abnormally tight rosette pattern of new foliage

Injury from board mites, cyclamen mites, etc.

Loss of sinuses or holes in new foliage of split – leaf plants

Reduced light intensity, especially once the plants are placed indoors

Leaf margins notched

Mechanical injury Injury from chewing insects Phytotoxicity from pesticide sprays

Translucent – tunnel pattern in foliage

Holes in foliage

Feeding injury from caterpillars, snails, or slugs / Dead areas that drop from leaf after tissue is killed by foliar pathogens Phytotoxicity from pesticides

Abnormally glossy leaf surface

Excessive amount of plant polish or plant shine product applied to leaf surface

Solution dripping from edges of foliage that is otherwise dry

Guttation : the loss of water from tiny holes that are present along the leaf margin Guttation occurs at night and early morning and is non injurious physiological process

Defoliation of plant

High soil salinity Plants moved from high to low light intensity Prolonged period in shipping container without light or gas exchange Chilling injury Excessive desiccation between irrigation periods Reduced humidity Poor soil aeration Injurious soil insects Foliage injury from mite feeding Parasitic nematodes Root rot pathogens Air pollution, especially elevated levels of ethelene Phytotoxicity from pesticides

Stems stunted

Lack of nutrient such as boron. or crop injury from certain mites, including broad mite and cyclamen mite Phytotoxicity from pesticides Insufficient light in growing area Close plant spacing

Insufficient light in growing area Close plant spacing

Few lateral branches on plants that naturally branch freely

Fascinated stems

Genetic Variation Virus or virus like disorders Herbicide injury

Basal stem rot or breakdown

High soil salinity Slow-release fertilizer placed against stems Excessive irrigation Poorly drained soils Fungus gnat infestation Fungal pathogen infection Bacterial pathogen infection Phytotoxicity from pesticides

Lesions or cankers on stem

Sun scald Mechanical injury Pest feeding injury Fungal infection Bacterial infection

Foliage and / or stems wilted

High soil salinity High leaf temperature and cool soil Excessively high temperature Insufficient water supply in soil Low humidity Cuttings or plants not rooted adequately Roots that developed outside of container were severed Root mealybugs or parasitic nematodes Reduced root size from fungal root pathogens

Cracked leaf and / or surface

Etched or pitted leaf and / or surface

Excessively high temperature Phytotoxicity from pesticides

Thin cork layer (tan or brown), which develops on leaves and stems as spots or streaks

Thrips or false spider mite feeding injury Certain plant pathogens Phytotoxicity from pesticides

Tip dieback or blight

Deficiency of calcium, copper. or boron Desiccation injury Mites such as broad mite and cyclamen mite Fungal infection Phytotoxicity from pesticides

Calcium

Epinasty of young shoot and leaves

Aphid feeding injury Virus or virus like diseases Phytotoxicity from pesticides, particularly some herbicides

Stems and leaves bent or oriented to one side

A phototropic response to side lighting

Bud and flower drop on some foliage plants with flowers

Temperature extremes Plant moisture stress Low humidity Reduced root system from numerous causes Mechanical injury Ethylene injury Phytotoxicity from pesticides

Stems exceedingly thing weak, wide spacing between leaves

Excessive fertilizer Inadequate light Tight spacing of plants Temperature too high

Stem thicker than normal and leaf spacing usually very close

High light intensity Wide plant spacing air turbulence

Unusual amount of red pigment

Phosphorus deficiency Cool temperatures Root rot pathogens Nematodes or root mealy bugs

Phosphorus

Development of a new color pattern

Segregation of vegetative tissues in a chimeral plant Mutation in meristematic region resulting in a Chimera

Loss of variegation

Excess fertilizer Low light intensity in production or holding areas Excess photoperiod indoors Leaf aging in some plants Segregation of vegetative tissues in a chimeral plant

Small, translucent artifacts from living creatures

Molted skins or empty puga cases form certain insects or mites

Whitish to darker – colored residue on surface of plant

Calcium, magnesium, and sodium compounds found in some water supplies, which leave an objectional deposit on foliage Some fertilizer materials that contribute to deposits on the foliage Residue from certain pesticides, particularly we table powder formulations of a given com­ pound are preferred for appearance when safe Airborne particulate material adhering to plant

Small inanimate bodies on

Fecal deposits from pests

Brown to rusty red film on foliage

High iron content in water used for overhead irrigation Heavy false spider mite infestation

Fine webbing on leaf or between leaflets

Spider mites and a few other mite species

Roots very shallow; fail to penetrate deep into the soil

Excessive bottom heat Soil kept too wet Soil – mix texture very fine with few large pore spaces Soil – mix compacted excessively Soil infested with root – rotting fungi, parasitic nematodes, or other root – infesting pests

Inadequate quantity of soil added to container at time of potting Soil washed out by splashing water Excessive soil-mix shrinkage in certain mixes Poor soil aeration Development of extensive root systems in some species, which push the plants upward in the container

Root system slow to develop

Factors listed as causing the previous problem plus: High soil salinity Soil temperature extremes Plant potted too deep Toxic components in soil mixture (e.g., certain types of bark) Phytotoxicity from pesticide drenches

Portions of exposed roots eaten

Snail or slug feeding damage

Roots rots

High soil salinity Soil kept too wet Soil-mix texture very fine with few spaces Soil mix compacted excessively Parasitic nematodes Root-rot pathogens, usually fungi

Roots develop extensively through bottom of container

Plant container placed on moist medium that supports root growth Plant left in production area or retail display too long

Knots or swollen areas on roots

Root-knot nematode injury Tuberous roots that develop naturally on some plant

Excessive root system tightly bound in containers

Plants not sold on schedule or not stepped up top a larger container

White or gray fuzzy masses on roots

Non injurious saprophytic fungi

Whole plant

Tissue torn or shed

Mechanical injury during growing, handling packing or shipping.

Shrinkage of leaf, stem or root tissues

High soil salinity Injurious soil insects Parasitic nematodes Fungal root rots Phytotoxicity from pesticides

Reduced rate of growth without drastic changes in typical plant characteristics

One or more essential elements in limited supply Excessive soil salinity Soil pH extremes Extremely low light levels, usually indoors Temperature extremes Excessive soil moisture Poor soil aeration Poorly drained container Low humidity Seedling variation in some plants Pot-bound root system Presence of plant pathogens or other pests that affect the root system or vascular system Phytotoxicity from pesticides

Seed fail to germinate

Nonviable seeds Seeds harvested prematurely Seeds stored for excessive periods Seeds stored at improper temperature or humidity High salinity of germination medium Germination medium dried during germination Destruction of seeds prior to emergence by rodents, insects, or plant pathogens Insufficient time for germination Impermeable seed coat Chemical inhibitors in seed Germination medium temperature too low Poor soil aeration High salinity of germination medium Fungal stem and root rot pathogens

High salinity of germination medium Fungal stem and root rot pathogens

Seedlings Damping – off

Some seedlings are white

Genetic seedlings common to certain species

Correction of nutrient disorder

After having diagnosed a nutrient disorder, the next step is to correct it in order to improve crop production. Methods of correcting nutrient deficiencies or toxicities vary according to agro climatic regions, the socioeconomic situation of the region, the magnitude of the disorder, and the nutrient or element involved. Use of efficient or tolerant cultivars in combination with fertilizers or amendments may be the best solution for correcting nutrient disorders in field crops.

Soil testing, plant analyses, visual foliar symptoms and crop growth response are the most common guides to the fertilization of field crops. Among these diagnostic techniques visual symptoms are the least expensive, but soil analysis is widely used for soil fertility evaluation. Quantities of fertilizer and lime are determined on the basis of soil test calibration studies for each crop.

Table 2. Methods of correcting nutrient deficiencies

Nutrient / element

Corrective measures

Addition of organic matter to the soil; Application of N fertilizers, including legumes in the crop rotation; use of foliar spray of 0.25to 0.5% solution of urea.

Adjustment of extreme pH: application of phosphorus fertilizer

Application of potassium fertilizers, incorporation of crop residues

Liming of acid soils; addition of gypsum

Application of dolomite limestone; foliar application of 2% magnesium sulfate solution

Use of fertilizer salt containing sulfur such as ammonium sulfate and single super phosphate; application of gypsum or elemental sulfur

Addition of zinc sulfate to soil; foliar spray of 0.1to 0.5% solution of zinc sulfate

Foliar spray of 2% iron sulfate or 0.02 to 0.05% solution of iron chelate ; use of efficient cultivars

Soil application of boron or foliar spray of 0.1 to 0.25% solution of borax

Liming of acid soils, soil application of sodium or ammonium molybdate

Applications of lime; use of tolerant species or cultivars.

Table 3. Tolerance of plant foliage to Mineral nutrient sprays

Formulation or salt

Kg per 400 L * of water

Urea NH4 NO3, (NH4)2 HPO4, (NH4)2 SO4 NH4Cl, NH4 PO4

3 - 5

H3PO4, others see N above

2-3

KNO3, K2,So4, KCI

CaCl2, Ca (NO3)2

1.5-2.5

MgSO4

3-5

FeSO4

3-6

MnSO4

3-12

ZnSO4

2-12

Sodium borate

Molybdenum

Sodium molybdate

0.1-0.15

* 400 L of solution is sufficient to spray on 1 ha of filed crop In a given agro climatic region,one of the greatest values of tissue analysis is in the prevention of deficiencies rather than their correction after they appear.

Soil analysis, Plant analysis, and visual symptoms are all useful and complementary in nutritional diagnosis of crop plants. These techniques provide information for evaluating the nutrient status of the soil – plant environment and for establishing the basis for fertilizer and lime applications.