Other TablesTable 4. Plant micronutrients.
| Element | Absorbed as | Signs of excess | Signs of deficiency | Notes |
| Iron (Fe) | Fe++, Fe+++ | Rare except on flooded soils. Interveinal chlorosis, primarily on young tissue, which eventually may turn white. | Soil high in Ca, Mn, P, or heavy metals (Cu, Zn); high pH; poorly drained soil; oxygen-deficient soil; nematode attack on roots. | Add Fe in the chelate form. The type of chelate needed depends on soil pH. |
| Boron (B) |
BO3- Borate |
Blackening or death of tissue between veins. | Failure to set seed, internal breakdown, death of apical buds. | |
| Zinc (Zn) | Zn++ | Shows up as Fe deficiency. Also interferes with Mg absorption. | "Little leaf" (reduction in leaf size), short internodes, distorted or puckered leaf margins, interveinal chlorosis. | |
| Copper (Cu) | Cu++, Cu+ | Can occur at low pH. Shows up as Fe deficiency. | New growth small, mis-shapen, wilted. | May be found in some peat soils. |
| Manganese (Mn) | Mn++ | Reduction in growth, brown spotting on leaves. Shows up as Fe deficiency. | Interveinal chlorosis of leaves followed by brown spots, producing a checkered effect. | Found under acid conditions. |
| Molybdenum (Mo) |
MoO4- (molybdate) |
Interveinal chlorosis on older or midstem leaves, twisted leaves (whiptail). | ||
| Chlorine (Cl) | Cl- | Salt injury, leaf burn. May increase succulence. | Leaves wilt, then become bronze, then chlorotic, then die; club roots. |
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