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.
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.
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.
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.
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.
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.
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.
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.
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.
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.