Key to Nutrient Deficiencies in Corn and Sorghum

Use the following key to help identify seven nutrient disorders observed in Nebraska corn and sorghum. BACK to the Soils page.

Symptom identification key for nutrient deficiencies in corn and sorghum. Select the best descriptor for your symptoms.
A1.	Symptoms appear first or are more severe on older and/or fully expanded leaves Select B1. or B2.		B1. Symptoms advance from leaf tip towards the base; no interveinal chlorosis Go to D
A1.			B2. Symptoms begin as interveinal or marginal chlorosis Go to E
A2.	Symptoms appear first or are more severe on younger leaves Go to C

C1.	Symptoms are prominent interveinal chlorosis or necrosis; veins are prominent over length of leaf	Iron deficiency
C2.	Symptoms begin as lesions, broad bands, or marginal leaf tips of chlorotic tissue or as generalized yellowing; veins are not prominent * Go to F

D1.	Pale green plants; chlorosis or necrosis advance from the leaf tip along the midrib (Courtesy of the International Plant Nutrition Institute)	Nitrogen deficiency
D2.	Dark green plants; dark yellow chlorosis advancing along purple color (Courtesy of the International Plant Nutrition Institute)	Phosphorus deficiency

E1.	Dark green plants with chlorosis along the leaf margins developing to brown striping and necrosis (Courtesy of the International Plant Nutrition Institute)	Potassium deficiency
E2.	Green-yellow plants with dark yellow interveinal chlorosis advancing to rust-brown necrosis	Magnesium deficiency

F1.	Pale yellow plants; uniformly yellow leaves without necrosis	Sulfur deficiency
F2.	Pale green plants; white to pale yellow bands in the lower half of the leaf which advance to pale brown or gray necrosis (Left photo courtesy of the International Plant Nutrition Institute)	Zinc deficiency