Signs of Nutrient Deficiency in plant

Element and Foliar symptoms
Nitrogen (N) General yellowish-green; moxe severe on older leaves. Stunted growth; small, fewer leaflets; early leaf drop. Dark green to blue-green, slightly smaller leaves. Veins, petioles, or lower surface may become reddish-purple, especially when young; death of lower needles in pmes.
Potassium (K) Partial chlorosis of most recently matured leaves in interveinal area beginning at tips, followed by necrosis. Older leaves may become brown and curl downward.
Calcium (Ca) Death of terminal buds, tip die- back, chlorosis of young leaves; leaves may become hard and stiff. Root injury is the first apparent sign.
Magnesium (Mg) Marginal chlorosis on older leaves followed by interveinal chlorosis. EIPS and margins may become brittle and curl upward.
Sulfur (S) Uniform chlorosis of new leaves; older leaves are usually not affected.
Iron (Fe) Interveinal chlorosis of young leaves (sharp distinction between green veins and yellow tissue between veins). Older basal leaves greener; exposed leaves blanched.
Manganese (Mn) Interveinal chlorosis of young leaves beginning at margins and progressing toward midribs; followed by necrotic spots.
Zinc (Zn) Young leaves may be yellow, small, deformed, or mottled with necrotic spots. There may be a tuft of leaves at shoot tips.
Boron (B) Terminal growth dies; later growth that develops has sparse foliage. Young leaves may be red, bronzed, or scorched. Leaves may be small, thick, distorted, or brittle.
Copper (Cu) Rosetting of terminal growth may die. Leaf symptoms not usually pronounced, but veins may be lighter than blades.
Molybdenum (Mo) Cupping of the older leaves; marginal chlorosis followed by interveinal chlorosis. Source: Pennsylvania Cooperative Extension