HOW DO I IDENTIFY A NUTRIENT DISORDER?Question 5:

Principal Plant ConstituentsElement % dry wt

C 45%O 45%H 6%

C, H, O are derived from water and carbon dioxide comprise >95% of plant dry plant mass

Primary and Secondary MacronutrientsNutrient % dry wt.

N 1.5%P 0.2%K 1.0%Ca 0.5%Mg 0.2%S 0.1%

Primary

Secondary

Derived primarily from soil solution

MicronutrientsMicronutrient mg/kg dry wt

Cl 100Fe 100B 20

Mn 50Zn 20Cu 6Mo 0.1Ni ???

Tissue levels of essential nutrients

95%

Nickel

Nutrient Deficiency SymptomsThe location of the deficiency symptom is related to nutrient mobility in the plant

• Mobile Nutrients: N, P, K, Mg, and. Symptoms occur in older leaves

• Immobile Nutrients: Fe, B, Mn, Cu, Ca, S and Zn. Symptoms occur in younger leaves

Diagnosing Can Be Difficult ….SYMPTOMS…. May be caused by more than one nutrient

Caused by excess of another (induced deficiency; toxicity)

http://www.ces.ncsu.edu/depts/hort/consumer/quickref/fertilizer/nutri_def.html

Often similar to effects of disease, herbicide damage

May be caused by environmental or physical factors (e.g. root damage, low temps)

chlorosischlorosis

Interveinal chlorosis

Interveinal chlorosis

NecrosisNecrosis

Nutrient Deficiency Symptoms

Guide Provided by the International Plant Nutrition Institute

Guide Provided by the International Plant Nutrition Institute

Nitrogen Deficiency Phosphorus Deficiency Potassium Deficiency

A nutrient must usually be in an ionized state before it can be assimilated by plants (must lose or gain and electron or have a charge)

1. Anion (negative charge):nitrate, phosphate, sulfate, chloride

2. Cation (positive charge): ammonium, Ca, Mg, K, Na, Fe

Boron (B) is an exception. Form being assimilated by plants H3BO3

Element Form Available to Plants

Mobility Functions Deficiency Symptoms

soil plant

Nitrogen(N)

NH4+, NO3

- YES YES Amino acids andChlorophyll synthesis

Chlorosis of older leaves that starts at tip and move along the middle of the leaves

Phosphorus (P)

HPO4-2, H2PO4- NO YES Energy, lipids component

Stunted growth, purpling of leaves, small-dark green leaves

Potassium (K) K+ NO YES Stomatal regulation, enzyme cofactor

Chlorosis and necrosis of leaf edges, white spots on leaf edges

Sulfur (S) SO4-2 YES NO Amino acids and

enzymes productionInterveinal chlorosis on young leaves (monocot plant)

Calcium (Ca) Ca+2 NO NO Cell wall component, enzyme cofactor, stimuli

Stunted growth, no root elongation, damage/disorders in storage tissues and terminal buds

Element Form Available to Plants

Mobility Function Deficiency Symptom

soil plant

Magnesium (Mg) Mg+2 NO YES Chlorophyll component, enzyme cofactor

Interveinal chlorosis on old leaves (pale yellow), necrosis

Iron (Fe) Fe2+, Fe3+ NO NO Enzyme component, e-transport, constituent of proteins, chlorophyll synthesis and component

Interveinal chlorosis on young leaves, stunted growth

Zinc (Zn) Zn2+ NO NO Enzymes component, synthesis of chlorophyll

Yellow/white broad band on new leaves, rosette

Copper (Cu) Cu2+ NO NO Enzymes & proteins (plastocyanin) component, e-transport

Chlorosis of young leaves, tips of leaves withered, curling of young leaves

Element Form Available to Plants

Mobility Functions Deficiency Symptoms

soil plant

Manganese(Mn)

Mn+2 NO NO Component of water splitting complex, involve in e-transport and oxidation and reduction system,

Interveinal chlorosis, yellow speckles on leaves

Nickel (Ni)

Ni+2 YES? YES? Component of enzyme urease and hydrogenase

Rosette, necrosis of leaf tip, dwarfing of foliage

Element Form Available to Plants

Mobility Functions Deficiency Symptoms

soil plant

Chloride (Cl)

Cl- YES YES Leaf turgor, stomatal regulation

Leaf edges roll up, chlorosis (speckles-like), leaves are wilting

Molybdenum (Mo)

MoO42- YES? YES? Components of

nitrogenase and nitrate reductase enzymes

Chlorosis in younger leaves (smear-like), pale cupped/deformed leaves

Boron (B)

H3BO3 YES NO Seed and cell wall formation, sugar translocation, germination of pollen, growth of pollen tubes

Growing points die and decay, thickened curled chlorotic/necrotic leaves

Need More Nutrition Information?

• Take Dr. Brenda Tubana’s Soil Fertility Courses– AGRO 4052 Soil Fertility and Nutrient Management– AGRO 7051 Advance Soil Fertility and Plant Nutrition– AGRO 7052 Micronutrients in Soils and Crops

Online Books….http://freetechebooks.com/doc-2011/soil-fertility-pdf.html