A Key to Plant Nutrient Deficiencies

This key will work if the plant is not diseased or has pest problem.

Symptoms. . . . . . . . . . . . . . . .Deficient Element

Older or lower leaves of plant mostly affected:

Effects mostly generalized over whole plant; more or less drying or firing of lower leaves; plant light or dark green.

Plant light green; lower leaves yellow with entire plant becoming yellow under prolonged stress. Growth is restricted and plant soon become spindly and older leaves drop. Nitrogen

Normal Nitrogen deficient

Plant dark green, often developing red and purple colors; stalks short and slender if element is deficient in later stages of growth.Phosphorus

Effects mostly localized; mottling or chlorosis with or without spots of dead tissue on lower leaves; Little or no drying up of lower leaves.

Mottled or chlorotic leaves; typically may redden, as with cotton; sometimes with dead spots; tips and margins cupped upward; stalks slender. Symptoms usually occur late in the growing season. Magnesium

Interveinal chlorosis, with early symptoms resembling nitrogen deficiency; older leaves chlorotic with veins remaining pale green. Leaf margins become necrotic and may roll or curl. Symptoms appear on younger leaves as deficiency progresses. Molybdenum

Spots of dead tissue small,usually at tips and between veins, more marked at margins of leaves; leaves cup back on themselves. Mild symptoms appear first on recently matured leaves, then becomes pronounced on older leaves. Symptoms are much more common late in the growing season. Potassium
Leaves may be abnormally small and necrotic areas between the veins at the tips of the leaves. Zinc

Newer or bud leaves affected, symptoms localized.

Terminal buds dies, following appearance of distortions at tips or bases of young leaves.

Young leaves of terminal bud at first typically hooked, finally dying back at tips and margins, so that later growth is characterized by a cut-out appearance at these points; fruit exhibit water-soaked lesions at blossom end, later becoming sunken, dark or leathery (tomato, pepper,& watermelon). Cavities develop in the root (carrots, celery). Collapse of the fruit epidermis (apples). Calcium

Young expanding leaves may be necrotic or distorted followed by death of growing points. Internodes may be short, especially at shoot terminals. Stems may be rough, cracked. Poor fruit set. Boron

Terminal bud commonly remains alive, wilting or chlorosis of younger or bud leaves with or without spots of dead tissue; veins light or dark green.

Young leaves permanently wilted (wither tip effect) without spotting or marked chlorosis. Onion bulbs are undersize and outer scales are thin and lightly colored. Copper

Young leaves not wilted, chlorosis present with or without spots of dead tissue scattered over the leaf.

Chlorosis is less marked near veins; looks like a wedge mottling. Chorotic areas eventually become brown, transparent, or necrotic. Manganese

Leaves uniformly light green, followed by yellowing and poor, spindly growth. Looks like nitrogen. Sulfur

Distinct yellow or white areas appear between veins. Veins green.Iron