[FONT=&]Nutrient[/FONT] | [FONT=&]Mode of Action[/FONT] | [FONT=&]Deficiency[/FONT] | [FONT=&]Excess /Comments[/FONT] |
[FONT=&]Iron (Fe)[/FONT] | [FONT=&]Absorbed as Fe++, Fe+++; accumulates in the oldest leaves and is relative immobile in the phloem; necessary for the maintenance of chlorophyll[/FONT] | [FONT=&]Interveinal chlorosis primarily on young tissue, which may become white; Fe deficiency may occur even if Fe is in the soil when: soil high in Ca, poorly drained soil, soil high in Mn, high pH, high P, soil high in heavy metals (Cu, Zn), oxygen deficient soils or when nematodes attack the roots; Fe should be added in the chelate form; the type of chelate needed depends upon the soil pH; foliar fertilization will temporarily correct the deficiency; may be deficient in centipedegrass where pH and P are high[/FONT] | [FONT=&]Rare except on flooded soils[/FONT] |
[FONT=&]Boron (B)[/FONT] | [FONT=&]Absorbed as B(OH)3-; important in enabling photosynthetic transfer; very immoble in plants[/FONT] | [FONT=&]Failure to set seed; internal breakdown of fruit or vegetable; death of apical buds, giving rise to witches broom; failure of root tip to elongate normally; young leaves become thick, leathery, and chlorotic; rust colored cracks and corking on young stems, petioles and flower stalks (e.g. heart rot of beets, stem crack of celery); breakdown occurs at the base of the youngest shoots[/FONT] | [FONT=&]Tips and edges of leaves exhibit necrotic spots coalescing into a marginal scorch (similiar to high soluable salts); oldest leaves are affected first; plants are easily damaged by excess application[/FONT] |
[FONT=&]Zinc (Zn)[/FONT] | [FONT=&]Absorbed as Zn++; enzyme activity[/FONT] | [FONT=&]Young leaves are very small, sometimes missing leaf blades; short internodes; distorted or puckered leaf margins; interveinal chlorosis[/FONT] | [FONT=&]Sever stunting, reddening; poor germination; older leaves wilt; entire leaf is affected by chlorosis, edges and main vein often retain more color; can be caused by galvanized metal.[/FONT] |
[FONT=&]Copper (Cu)[/FONT] | [FONT=&]Absorbed as Cu++, Cu+; enzyme activity[/FONT] | [FONT=&]New growth small, misshapen, wilted; may be found in some peat soils; in some species young leaves may show interveinal chlorosis while tips of older leaves remain green.[/FONT] | [FONT=&]Can occur at low pH; shows up as Fe deficiency[/FONT] |
[FONT=&]Manganese (Mn)[/FONT] | [FONT=&]Absorbed as Mn++[/FONT] | [FONT=&]Interveinal chlorosis with smallest leaves remaining green producing a checkered effect; grey or tan spots usually develop in chlorotic areas; dead spots may drop out of the leaf; poor bloom size and color; induced by excessively high pH.[/FONT] | [FONT=&]Reduction in growth, brown spotting on leaves; shows up as Fe deficiency; found under strongly acid conditions[/FONT] |
[FONT=&]Molybdenum (Mo)[/FONT] | [FONT=&]Absorbed as MoO4-[/FONT] | [FONT=&]Interveinal chlorosis on older or midstem leaves; twisted leaves (whiptail); marginal scorching and rolling or cupping of leaves; nitrogen deficiency symptoms may develop[/FONT] | [FONT=&]Intense yellow or purple color in leaves; rarely observed[/FONT] |
[FONT=&]Chlorine (Cl)[/FONT] | [FONT=&]Absorbed as Cl -[/FONT] | [FONT=&]Wilted leaves which become bronze then chlorotic then die; club roots[/FONT] | [FONT=&]Salt injury, leaf burn, may increase succulence[/FONT] |
[FONT=&]Cobalt (Co)[/FONT] | [FONT=&]Absorbed as Co++[/FONT] | [FONT=&]This need by plants recently established; essential for Nitrogen fixation[/FONT] | [FONT=&]Little is known about its deficiency or toxicity symptoms[/FONT] |
[FONT=&]Nickel (Ni)[/FONT] | [FONT=&]Absorbed as Ni+[/FONT] | [FONT=&]This need by plants recently established; essential for seed development[/FONT] | |