Fertilizer Deficiency Symptoms in Corn

Nitrogen

• Corn suffering from a nitrogen deficiency shows a lack of characteristic green coloration in all foliage. Lower leaves turn yellow and develop a V-shaped yellow patch beginning at the tip of the leaf and running up the middle of the blade. Stalks may also turn yellow.

Potassium

• Older leaves begin to turn yellow along the edges and may progress to brown, dry edges. As the deficiency proceeds, leaves higher up on the plant may be affected. Typically, the tops of leaves maintain their characteristic green.

Zinc

• Corn plants experiencing a zinc deficiency may take on a striped appearance. Wide bands of yellow appear in the middle of the leaf and progress outward. Symptoms of a zinc deficiency are most noticeable in upper leaves.

Phosphorus

• According to the University of Minnesota Extension, a phosphorus deficiency presents with purple margins along the leaves. Fabián Fernández from the University of Illinois adds that the purple or reddish hue typically appears in older leaves and that the deficiency may cause stunted growth.

Magnesium

• A magnesium deficiency begins with white or yellow stripes between veins. These darken to reddish purple as the deficiency progresses. The edges and tips of the leaf may turn brown and die.

Sulfur

• A sulfur deficiency causes yellowing of leaves, similar to a nitrogen deficiency, but differs in that it affects the new leaves as they appear. It may also cause a streaking effect with slender pale green or yellow stripes between the veins of the leaf.

Iron

• An iron deficiency in corn presents with dark green stripes in pale yellow leaves. If the condition is severe the entire leaf may turn pale yellow or white.