Nitrogen (N)

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N deficiency in young corn is characterized by plants that are stunted, spindly, and pale green to yellow over the entire plant.

N deficiency later in the season is characterized by yellowing of the lower leaves beginning at the leaf tips.  As the deficiency progresses the yellowing proceeds towards the basal portion of the leaf along  the midrib in a V-shaped pattern.  The leaf margins remain green.

Phosphorus (P)

P deficient plants may remain darker green than normal plants and develop purple discoloration first on the underside and later throughout.  Plants grow slowly, stalks are thin and shortened and maturity is delayed.

Potassium (K)

K deficiency appears first as yellowing on the tips of lower leaves and progresses along the outer leaf margins as yellow, light tan, and then brown discoloration. The innner part of the leaf blade near the midrib usually remains green. Chlorotic areas may develop throughout the leaf. Stalks of deficient plants are weak and tend to lodge. The ears are chaffy and unfilled.

Calcium (Ca)

Ca deficiency is very rare on corn. Plants are severely stunted and new leaves exude a gelatinous like material and new leaves stick together. Because Ca deficiency is favored by low pH (<5.2) and low soil Ca, aluminum and manganese toxicity symptoms will usually be exhibited before Ca deficiency symptoms.

Magnesium (Mg)

Initially Mg deficiency is expressed as interveinal chlorosis on the older leaves and progresses upwards as the deficiency intensifies. Older leaves may become reddish-purple and the tips and margins may die. Older leaves may fall off with prolonged deficiency.

Sulfur (S)

S deficiency in corn with an ample supply of N appears as interveinal chlorosis of the younger leaves and may be confused with those of iron, manganese and zinc deficiencies. Symptoms in corn with a low supply of N may occur on older leaves as interveinal chlorosis. Plants are small and spindly with short slender stalks. Growth rate is retarded and maturity is often delayed.

Boron (B)

Deficiency symptoms in corn are rare on heavy textured soils but may occur on sandy acid leached soils. Initially yellow and white spots develop between the veins on young leaves; the spots often coalesce to form streaks; internodes do not elongate resulting in bushy appearance; growing points may die; leaves may become curled. Severe B deficiency results in short bent cobs with underdeveloped tips and poor kernel development.

Copper (Cu)

Deficiency appears first on corn within the whorl and on young expanding leaves as interveinal chlorosis; new leaves emerging from the whorl may remain tightly curled; leaf tips and margins may die and curl in a spiral-like manner; plants are stunted.

Iron (Fe)

Iron deficiency is manifested as interveinal chlorosis on the uppermost leaves; the entire length of the leaf is affected; as the deficiency intensifies the uppermost leaves may become almost white between the veins and interveinal chlorosis spreads to older leaves. Corn has a low requirement for Fe and deficiencies are rare. Deficiencies occur primarily on alkaline soils (pH greater than 7.0). Low or deficient levels may be detected on sandy soils high in P, Cu, Mn, or Zn and under cool growing conditions in early spring.

Manganese (Mn)

Manganese deficiency symptoms appear on the uppermost recently mature leaves as interveinal chlorosis (streaked). Manganese deficiencies are rare on corn grown on soils with a pH of 6.0 and 6.3. Deficiencies have been observed on corn grown on sandy soils with pH values greater than 6.5.

Zinc (Zn)

Zinc deficiency in corn is exhibited on the upper leaves as interveinal chlorosis. The veins, midrib and leaf margin remain green. As the deficiency intensifies “feather like” bands develop on either side of the midrib and the leaves may turn almost white (hence the term “white bud” was coined to describe Zn deficient corn plants); internodes are short resulting in stunted plants.