N – Nitrogen: Component of proteins, hormones, chlorophyll, vitamins and enzymes. Promotes stem and leaf growth. The ammoniacal and nitrate forms are used directly by plants for stem and leaf growth. The urea form of nitrogen must be broken down by soil borne microorganisms or urease before it can be utilized by the plant. Urea can cause leaf tip and root burn. Deficiency symptoms: reduced yields, yellowing of leaves, stunted growth. Excess nitrogen can delay fruiting and flowering.
P – Phosphorus: Essential for seed germination, photosynthesis, protein formation, overall growth and metabolism, flower and fruit formation. Deficiency symptoms: purple stems and leaves, retarded growth and maturity, poor flowering and fruiting. Large amounts without zinc cause zinc deficiency. Low pH (<4) ties up phosphates in organic soils. Excessive amounts may be toxic to plants.
K – Potassium: Essential for formation of sugars, carbohydrates, proteins, cell division. Adjusts water balance; improves stem rigidity and cold hardiness; enhances flavor, color and oil content of fruits; important for leafy crops. Deficiency symptoms: spotted, curled or burned look to leaves; lower yields.
Ca – Calcium: Activates enzymes; structural part of cell walls; influences water movement, cell growth and division. Required for uptake of nitrogen and other minerals. Leached from soil by watering. Immobile: requires a constant supply for growth. Deficiency symptoms: stunting of new growth in stems, flowers, roots; black spots on leaves and fruit; yellow leaf margins.
Mg – Magnesium: Critical component of chlorophyll; needed for functioning of enzymes for carbohydrates, sugars and fats; fruit and nut formation; germination of seeds. Deficiency symptoms: yellowing between veins of older leaves; chlorosis; leaf droop. Leached by watering. Foliar spray to correct deficiencies.
S – Sulfur: Component of amino acids, proteins, vitamins, enzymes. Essential for chlorophyll. Imparts flavor to many vegetables. Deficiency symptoms: light green leaves. Water supply may contain sulfur. Leached by watering.
Si – Silicon: Component of cell walls; enhances resistance to sucking insects and fungi. Foliar sprays reduce populations of aphids on some plants. Enhances leaf presentation; improves heat, drought and cold tolerance; improves photosynthesis; extends bloom life. Deficiency symptoms: wilting, poor fruit and flower set, increased susceptibility to insects and disease. Disease resistance is enhanced by regular foliar feeding. (Si is a macronutrient for most plants.)
B – Boron: Affects at least 16 functions: flowering, pollen germination, fruiting, cell division, water relationships, movement of hormones, cell wall formation, membrane integrity, calcium uptake, movement of sugars. Immobile; easily leached. Deficiency symptoms: terminal bud die back causes rosette of thick, curled, brittle leaves or brown, discolored, cracked fruits, tubers and roots.
Cl – Chlorine: Involved in osmosis (movement of water or solutes in cells), ionic balance necessary to take up mineral elements and photosynthesis. Deficiency symptoms: wilting, stubby roots, yellowing, bronzing. Scents in some plants may be decreased. Leached by watering. Excessive amounts may be toxic to plants.
Co – Cobalt: Required by nitrogen fixing bacteria; formation of B12 vitamin; formation of DNA. Will extend life of cut flowers such as roses. Deficiency symptoms: may result in nitrogen deficiency.
Cu – Copper: Necessary for nitrogen metabolism; component of enzymes – may be part of enzyme systems that use carbohydrates and proteins. Bound tightly in organic matter. May be deficient in highly organic soils. Not readily lost from soil but may be unavailable. Deficiency symptoms: die back of shoot tips; terminal leaves develop brown spots. Excessive amounts may be toxic to plants.
Fe – Iron: Enzyme functions; catalyst for synthesis of chlorophyll; essential for new growth. Deficiency symptoms: pale leaves, yellowing of leaves and veins. Leached by water and held in lower parts of soil. High pH soils may have iron present but unavailable to plants.
Mn – Manganese: Enzyme activity for photosynthesis, respiration and nitrogen metabolism. Deficiency symptoms: young leaves are pale with green veins similar to iron deficiency; advanced stages-leaves are white and drop; brown, black or gray spots may appear next to veins. Plants in neutral or alkaline soils often show deficiencies. Acid soils may increase uptake causing toxicity.
Mo – Molybdenum: Structural part of enzymes that reduce nitrates to ammonia for amino acid development essential to protein formation; required by nitrogen fixing bacteria. Deficiency symptoms: pale leaves with rolled, cupped margins. Seeds may not form. Nitrogen deficiency may occur if plants are lacking Mo.
Na – Sodium: Improves nitrogen metabolism in many plants, involved in osmotic (water movement) and ionic balance in plants. Deficiency symptoms: yellowing of leaves and leaf tip burn; may inhibit flower formation. Excessive amounts may be toxic to plants.
Ni – Nickel: Recently recognized as essential. Ni is an essential mineral for the urease enzyme which breaks down urea into usable forms of nitrogen. It is also essential for iron uptake. Seeds will not germinate without Ni.
Zn – Zinc: Improves nitrogen metabolism in many plants, involved in osmotic (water movement) and ionic balance in plants. Deficiency symptoms: yellowing of leaves and leaf tip burn; may inhibit flower formation.