Nutrient	Boron B
Macro or Micro?	Micronutrient
Main function:	Essential for seed and fruit development. Important in tissue respiration and cell division, pollination, carbohydrate synthesis and transport. Necessary for movement of sugars, for reproduction, and for water intake by cells. Aids production of sugar and carbohydrates.	Affects flowering, pollen germination, fruiting, cell division, nitrogen metabolism and hormone movement. Helps in use of nutrients and regulates other nutrients. Tends to keep calcium in a soluble form.
Deficiency symptoms	Slows and stunts growth. Causes distorted and dead growing tips (including apical buds), hollow stems and deformed fruit. In serious cases, death occurs on growing tips and root tips. Failure to set seed. Internal breakdown.	Storage organ development is impaired and stems crack or are hollow. Young leaves affected first. Leaves often scorched and sometimes mottled and discolored; leaf distortion with some species. Rough patches may appear on skin surfaces. Boron is sometimes deficient in the Pacific Northwest.
Plant takes in by:	Soil.
How does pH affect?	Availability best below 8.0 and above 8.5.	Loses availability between 8.0 and 8.5.
Added thru fertilizer?	Generally not added.	Sources are manure, organic matter and borax.
Toxicity symptoms	Foliar symptoms occur first on the older leaves and include a yellowing along the midrib and the large lateral veins. May cause scorched leaf edges similar to potassium or magnesium deficiencies.	Symptoms in apples include dieback of twigs, greatly enlarged nodes on 1- and 2-year-old twigs, early fruit maturity, internal breakdown, and dropping of fruit. In peaches, vegetative symptoms include necrotic lesions on leaves, crinkling of margins and tips of leaves, reduced flower bud formation and set, and pit splitting.

Nutrient	Calcium Ca
Macro or Micro?	Macronutrient
Main function:	Major ingredient in cell walls. Cell growth and division. Important for root growth, especially root tips. Involved in root and leaf development. Responsible for strong growth, important in fruit set and water uptake.	Provides for normal transport and retention of other elements as well as strength in the plant. Nitrogen assimilation. Co-factor for some enzymes. Counteracts effect of alkali salts and organic acids within a plant.
Deficiency symptoms	Distorted terminal leaves. Failure of terminal bud to grow; inhibition of bud growth. Causes poorly developed roots with weak tips and reduced growth. Young leaves are distorted with hooked tips and curled margins. Cupping of maturing leaves.	Some plants turn black with dead spots in midrib. Death of root tips. Weak growth. Blossom-end rot of many fruits; pits on root vegetables. Can cause deficiency of magnesium and potassium that can be taken up.
Plant takes in by:	Soil.
How does pH affect?	Availability best at pH above 6.0.	Loses availability at 5.5.
Added thru fertilizer?	Yes. Ca is important to pH control and rarely is deficient if the correct pH is maintained. Water stress (too much or too little) can affect Ca relations within plants, causing deficiency in the location where Ca was needed at the time of stress.	Lime (calcium) is often added to the soil, but its function is primarily to reduce acidity and not, in the strict sense, to act as a fertilizer. Also apply dolomitic lime, gypsum and superphosphate. Another source lists calcium sulfate, calcium nitrate and calcium carbonate.
Toxicity symptoms	No known symptoms are associated with toxic levels of calcium.	High Ca usually causes high pH, which then precipitates many micronutrients so that they become unavailable to plants.

Nutrient	Carbon C
Macro or Micro?	Macronutrient
Main function:	Basic building block of life. Important in manufacture of sugar during photosynthesis. Combines with H and O to form carbohydrates for respiration.	Plants use light energy to convert atmospheric carbon (CO2) into biological carbon (simple sugars).
Deficiency symptoms	Plants take up whatever carbon they need; no carbon would mean death.
Plant takes in by:	Air.	Absorbed as CO2 from atmosphere during photosynthesis.
How does pH affect?	pH does not affect the availability of this element.
Added thru fertilizer?	No
Toxicity symptoms	No toxicity because the plant takes in only what is needed.

Nutrient	Chlorine Cl
Macro or Micro?	Micronutrient
Main function:	Required in photosynthetic reaction. Required for growth and development of roots and shoots. Regulates cell turgor pressure.	Increases disease resistance. Aids plant metabolism; may affect carbohydrate metabolism. Seems to be involved in water regulation. Only trace amounts are required.
Deficiency symptoms	May cause stubby roots and wilting. Increased disease.	Chlorotic leaves, some leaf necrosis and bronzing.
Plant takes in by:	Soil and water.
How does pH affect?	Unable to find (per Cindy).
Added thru fertilizer?	Yes, with chloride salts. Nutritional benefits have also been reported.	Needed in very small amounts and is generally available in the soil. Sometimes added to increase disease resistance of many crops.
Toxicity symptoms	May cause leaf edges to scorch similar to potassium deficiency. Salt injury, leaf burn.	May increase succulence.

Nutrient	Copper Cu
Macro or Micro?	Micronutrient
Main function:	Necessary for production of proteins. Essential in several enzyme systems (proteins), particularly in new tissues. Important for reproductive growth. Affects how well a plant resists diseases. Affects how well a plant controls moisture.	Helps utilize proteins. Aids in root metabolism. Promotes long storage. Connected with respiration and photosynthesis. Intensifies color and flavor.
Deficiency symptoms	Symptoms vary, although mostly plants are stunted. New growth is small, mis-shapen and wilted. Causes bluish green leaves which may wither or fail to unfold. Younger leaf tips may be yellow at edge; growing tips may form rosettes.	Older leaves develop chlorosis. Wilting is usually first symptom to occur in young tips, buds and shoots. Growing tip dies and fruit is small and imperfect due to failure of fertilization and fruit set.
Plant takes in by:	Soil.
How does pH affect?	Availability best in pH below 8.0.	Loses availability at 8.5.
Added thru fertilizer?	Rarely and only in small quantities. Can be highly toxic at low levels, so application is not recommended except when need has been established.	Copper sulfate or other copper salts.
Toxicity symptoms	Shows up as an iron deficiency. Can occur at low pH.	Symptoms are almost non-existent under orchard conditions, but when present they may resemble those of zinc deficiency. Excess copper may cause iron deficiency.

Nutrient	Hydrogen H
Macro or Micro?	Macronutrient
Main function:	Necessary for plant growth. Essential for photosynthesis and respiration. H combines with oxygen to make water needed for photosynthesis.	H is bonded with carbon and oxygen to form starches and sugars—when the bonds are broken, energy is released that is needed for all biological functions.
Deficiency symptoms	Plant takes up whatever H it needs; lack of H would mean death. Dessication.	If H is deficient, the plant will die due to inability to perform photosynthesis and respiration.
Plant takes in by:	Water.
How does pH affect?	Does not affect availability.
Added thru fertilizer?	No.
Toxicity symptoms	No toxicity of pure H; however, in the form of water-logged soils, it can suffocate roots, promote fungal disease and cause root rot.	Plants take in H as needed.

Nutrient	Iron Fe
Macro or Micro?	Micronutrient
Main function:	Required for oxygen and energy transfer, plant enzyme functions and photosynthesis.	Essential to chlorophyll production. Involved in formation of many compounds.
Deficiency symptoms	Young leaves are affected first and are small and chlorotic, often with green along the veins. Older leaves tend to be darker green. Dead spots may develop between veins. Leaves drop and dry prematurely. In severe cases, total bleaching of foliage.	Symptoms are similar to magnesium deficiency. Soil high in calcium, manganese, phosphorus or heavy metals (copper, zinc) High pH Poorly drained, oxygen-deficient soil Nematode attack on roots. Excess lime may cause iron deficiency.
Plant takes in by:	Soil and leaves.
How does pH affect?	Availability best at pH below 7.0.	Loses availability at 8.0.
Added thru fertilizer?	Usually present in soil in ample quantities. Add Fe in chelate form—the type of chelate needed depends on soil pH. Foliar applications of iron chelates, ferrous sulfate, or ferrous ammonium sulfate.	Commonly used as a foliar application due to the lack of plants’ ability to take up Fe from the soil.
Toxicity symptoms	Rare except on flooded soils. Interveinal chlorosis, primarily on young tissue, which eventually may turn white.	Although rare in the field, an excess of iron usually produces symptoms similar to those of manganese deficiency.

Nutrient	Magnesium Mg
Macro or Micro?	Macronutrient
Main function:	Essential in chlorophyll production (photosynthesis), formation of amino acids and vitamins. Essential in formation of fats and sugars. Important in cell multiplication and seed production. Important in most enzyme reactions.	Helps give plants their green color. Neutralizes organic acids. Aids in seed germination. Helps activate many plant enzymes needed for growth vital to chlorophyll production, for food transport and manufacture of sugar, fat and oil.
Deficiency symptoms	Different symptoms in different plants, but commonly causes leaf yellowing with brilliant tints. Reduction in seed production. Mottling and yellowing start at the leaf tips and progress to the center of the veins, which often remain green.	Symptoms usually show first on older leaves. Leaves may suddenly drop without withering . Causes cupped leaves. Symptoms can often be confused with those of iron and magnesium deficiencies.
Plant takes in by:	Soil.
How does pH affect?	Availability best at pH below 6.5.	Loses availability at 7.5.
Added thru fertilizer?	Mg is commonly deficient in foliage plants because it is leached and not replaced. A weak solution foliar spray with magnesium sulfate, and dolomitic limestone (outdoors).	Mobile in plants. Soil minerals, organic material, fertilizers in the form of lime. Epsom salts at a rate of 1 teaspoon per gallon may be used two times per year.
Toxicity symptoms	Symptoms of excessive magnesium levels are not specific but usually appear as a deficiency of either potassium or calcium.	Interferes with calcium uptake.

Nutrient	Manganese Mn
Macro or Micro?	Micronutrient
Main function:	Catalyst for enzyme systems involved in breakdown of carbohydrates and nitrogen metabolism. Activator for enzymes in growth process.	Important for chlorophyll formation. Chlorophyll synthesis, acts as co-enzyme.
Deficiency symptoms	Causes different symptoms in different plants but commonly causes leaves to turn yellow while veins stay green. Unlike magnesium deficiency, manganese deficiency symptoms seldom develop so far as to produce interveinal chlorosis, the chlorosis normally being confined to leaf margins. Interveinal chlorosis of leaves followed by brown spots produces a checkered effect.	The other distinguishing characteristic is that manganese deficiencies appear on the oldest leaves first, and the finest leaf veins do not remain green as they do with iron deficiencies. White or gray specks may appear on leaves. Similar to iron deficiency.
Plant takes in by:	Soil.	Primarily in the form of the ion (Mn++)
How does pH affect?	Availability best at pH below 6.5.	Loses availability at 7.5.
Added thru fertilizer?	Rarely, and only in small quantities. Required with zinc in foliar spraying of commercial citrus.	Other tree crops may show deficiencies, but otherwise there is not common recognition of requirements for this element in fertilizer programs in the west.
Toxicity symptoms	Reduction in growth. Brown spotting on leaves. May cause calcium deficiency. Shows up as iron deficiency.	Excess may cause iron deficiency and symptoms similar to magnesium deficiency. “Measles” is a disorder of apples, especially Delicious and Jonathan. It is caused in part by an excess of manganese accompanied by low calcium levels.

Nutrient	Molybdenum Mo
Macro or Micro?	Micronutrient
Main function:	Protein synthesis. Essential to nitrogen fixation (nitrate enzymes) and for formation of root nodules in beans and peas.	Helps in the use of nitrogen. Plays an important role in development.
Deficiency symptoms	Pale leaves look like nitrogen deficiency with some marginal leaf chlorosis. Yellow mottling and dead spots on leaves. Interveinal chlorosis on older or midstem leaves.	New leaves may twist (whiptail) and cup. In some plants, the growing tips are distorted or killed. Leaves appear blue-green. Mimics nitrogen deficiency symptoms.
Plant takes in by:	Soil.
How does pH affect?	Availability best at pH above 6.5 and greater.	Loses availability under 6.5.
Added thru fertilizer?	Generally available in the soil.
Toxicity symptoms	Very rare Discoloration of leaves.	Can be toxic to livestock.

Nutrient	Nickel Ni
Macro or Micro?	Micronutrient
Main function:	Helps plants use nitrogen correctly (“liberate” nitrogen from the soil). Helps plants absorb iron from the soil. Helps seed germination.	Helps plants fight off diseases. Forms an enzyme that breaks down urea.
Deficiency symptoms	Reduces utilization of iron. Iron chlorosis.	Symptoms of nitrogen deficiency.
Plant takes in by:	Soil.
How does pH affect?
Added thru fertilizer?	Not usually—not leachable; usually enough in the soil.
Toxicity symptoms	Chlorosis and necrosis of leaf margins.

Nutrient	Nitrogen N
Macro or Micro?	Macronutrient
Main function:	Critical to photosynthesis, cell growth and development. Necessary part of all proteins, enzymes and metabolic processes. Involved in synthesis and transfer of energy. Constituent of proteins and chlorophyll. Increase seed and fruit productions.	Stimulates leaf and stem growth. Keeps leaves green. Improve quality of leaf and forage crops. Rapid growth. Only element routinely needed for trees. Most limiting factor of all nutrients.
Deficiency symptoms	Reduced growth, smaller and pale yellowish green leaves. Yellowing of foliage begins with older leaves first since nitrogen is readily moved from old to new growth. Firing of tips and margins beginning with mature leaves. Lower leaves turn yellow and die.	New growth sparse, undersized. Plants grow slowly and may drop foliage prematurely. Stunted growth, delayed maturity. Roots are overlarge.
Plant takes in by:	Soil and air.
How does pH affect?	Availability best at pH between 6.0 and 8.0.	Loses availability below 5.5 and above 8.5.
Added thru fertilizer?	Yes, commonly supplemented through fertilizer. Leachable. Mobile in plants.	Uptake is inhibited by high phosphorus levels. The N:K ratio is extremely important. In soils with a high C:N ratio, more N should be supplied.
Toxicity symptoms	Symptoms appear as an excessive amount of shoot growth accompanied by dark green foliage and delayed leaf drop in the fall. As nitrogen increases above the optimum, fruit color is reduced and maturity is delayed.	In apples and pears, flavor and storage life are reduced. May cause potassium deficiency. Most limiting factor of all nutrients.

Nutrient	Oxygen O
Macro or Micro?	Macronutrient
Main function:	Important to photosynthesis—CO2 combines with H2) to form sugars for photosynthesis.	Required for normal anaerobic respiration (converting food into energy). Required for many growth processes.
Deficiency symptoms	Plants take up whatever they need; no oxygen would mean death. When O is scarce, as in flooded conditions or severe soil compaction, respiration uses food at a much higher than normal rate which damages roots.	Fungal diseases attach damaged roots, causing root rot. If conditions persist, roots will die.
Plant takes in by:	Air and water.
How does pH affect?	pH does not affect availability.
Added thru fertilizer?	No.
Toxicity symptoms	No toxicity because plants take in only what is needed.

Nutrient	Phosphorus P
Macro or Micro?	Macronutrient
Main function:	Essential to photosynthesis, respiration and storing carbohydrates (energy). Involved in cell division. Stimulates root development. Involved in formation of all oils, sugars, starches, etc.	Important for early plant establishment, germination and growth of seeds, flowering and fruit ripening.Withstanding stress; effects rapid growth. Greater hardiness and disease resistance. Proper plant maturation.
Deficiency symptoms	Stunted growth; sparse foliage growth. Reduced growth and small leaves that drop early, starting with the oldest leaves Leaf edges often turn scorched brown. Leaves may develop spots. Leaf edges roll and burn.	Leaf color is dull, bluish green that turns purplish or bronzy. Shoots are short and spindly Reddish purple leaves (older tissue), stems and branches. Younger leaves may show red pigmentation. Reduced yields of seeds and fruits.
Plant takes in by:	Soil.
How does pH affect?	Availability best at pH between 6.5 and 7.5.	Loses availability below 6.0 and above 8.0.
Added thru fertilizer?	No, not for trees. Very immobile in the soil; usually added at planting.
Toxicity symptoms	Usually expressed as deficiencies of one or more of the essential heavy metals such as zinc, copper, iron and manganese. Since deficiency symptoms of these elements may also be induced by excesses of phosphorus, visual foliar symptoms of phosphorus toxicity are not reliable.	Shows up as micronutrient deficiency of zinc, iron or cobalt. Excess P may cause potassium deficiency. Hardly moves within the soil.

Nutrient	Potassium K
Macro or Micro?	Macronutrient
Main function:	Maintains water regulation in cells, cell strength, transpiration, photosynthesis, carbohydrate (energy) formation and storage, and fruit quality. Helps build protein, photosynthesis and fruit quality. Helps increase meristematic activity, resulting in better growth.	Activator of many enzymes; open and close stomata. Promotes general vigor (increased resistant to disease, drought and frost) and sturdy growth. May cause potassium deficiency. Turf grass needs same or more K than nitrogen; especially in the fall.
Deficiency symptoms	Stunted growth with leaves close together; starting with older leaves. Tips and edges turn scorched brown and leaf edges roll. Older foliage is yellowish and may have brown tips and margins near leaf edge or between veins. Leaf burn, spotting and mottling on lower leaves follows poor growth.	Foliage growth is sparse. Younger leaves may show red pigmentation. Reduced yields. Weak root systems and stalk.
Plant takes in by:	Soil.
How does pH affect?	Availability best above 6.0.	Loses availability below 6.0.
Added thru fertilizer?	Yes; commonly supplemented through fertilizer. Generally adequate in soil for trees and shrubs. Can leach in sandy soils; otherwise it hardly moves in the soil. Mobile in plants.	N:K balance is important. High nitrogen: low potassium favors vegetative growth; low N:high K promotes reproductive growth (flowers, fruit).
Toxicity symptoms	No known visual symptoms are directly attributable to high levels of potassium; however, magnesium deficiencies tend to appear when there are high levels of potassium.	Causes nitrogen deficiency in plants and may affect the uptake of other positive ions. Excess K may cause calcium and magnesium deficiencies.

Nutrient	Sulfur S
Macro or Micro?	Macronutrient
Main function:	Necessary for chlorophyll formation. Essential for protein production. Promotes activity and development of enzymes and vitamins. Improves root growth, seed production and frost hardiness. Helps make nutrients more available. Lowers pH.	Increases vitamins and proteins in plants. Improves color. Responsible for odor and flavor of some legumes and brassicas. Promotes nodule formation on legumes, growth, seed production and frost hardiness.
Deficiency symptoms	Slow growth with small round leaves that roll upward and are stiff and brittle. Leaves drop off and tip buds die. Similar to nitrogen.	Leaves go pale yellow (chlorosis) with the whole plant being affected, though often younger leaves are affected first.
Plant takes in by:	Soil. It may also be absorbed from the air as a by-product of combustion.	Also in some fertilizers as an impurity; gypsum increases soil sulfur levels.
How does pH affect?	Availability best at pH below 6.0.	Loses availability above under 6.0..
Added thru fertilizer?	No. Usually present in soil in ample quantities. Leachable; not mobile in plants.	S is often a carrier of impurity in fertilizers and rarely is deficient. In our area we need to add S to correct pH a little bit (per Cindy).
Toxicity symptoms	Sulfur excess is usually in the form of air pollution. Premature leaf drop.	If the soil needs calcium but has alkaline pH, add calcium sulfate.

Nutrient	Zinc Zn
Macro or Micro?	Micronutrient
Main function:	Essential for transformation of carbohydrates. Essential for growth regulation (plant size and maturity). Essential in regulating sugar consumption.	Necessary for production of proteins. Improves efficiency of chlorophyll function. Important in enzyme systems, particularly for absorption and usage.
Deficiency symptoms	Leaf yellowing between veins, usually with purple or dead spots, starting with older leaves. Causes bright interveinal chlorosis in young and mid-shoot leaves, usually with purple or dead spots starting with older leaves. Leaves are close together, reduced in size, with distorted or puckered margins.	New growth may be delayed. New leaves may be small, narrow. Small, deformed leaves that fail to elongate (resetting). Fruit trees show resetting dieback, little leaves and premature leaf fall. Fruiting is reduced.
Plant takes in by:	Soil.
How does pH affect?	Availability best at pH below 7.0.	Loses availability above 8.5.
Added thru fertilizer?	Source: soil, zinc oxide, zinc sulfate, zinc chelate.
Toxicity symptoms	Symptoms are rare and most likely are masked by secondary symptoms resembling those of other micronutrient toxicities. Interferes with magnesium absorption.	Shows up as iron deficiency. Excess zinc may cause iron deficiency.

Miscellaneous notes from class:

Fertilizing: macronutrients—mostly added in the soil

micronutrients—foliar feeding is most effective

Balance is needed between calcium, potassium and magnesium.

Balance is needed between phosphorus and nitrogen; they do affect each other.