Guide to Nutrient Deficiency Symptoms

Nutrient Deficiency Symptoms in Leaves

 

Healthy leaves shine with a rich dark green color when adequately fed.

Healthy Leaf
Drawing: healthy corn leaf.

Phosphate shortage marks leaves with reddish-purple, particularly on young plants.

Phosphate Shortage
Drawing: corn leaf showing damage from phosphate shortage.

Potash deficiency appears as a firing or drying along the tips and edges of lowest leaves.

Potash Deficiency
Drawing: corn leaf showing potash deficiency symptoms

Nitrogen hunger sign is yellowing that starts at the tip and moves along middle of leaf.

Nitrogen Hunger
Drawing: corn leaf showing nitrogen hunger symptoms.

Magnesium deficiency causes whitish strips along the veins and often a purplish color on the underside of the lower leaves.

Magnesium Deficiency
Drawing: corn leaf showing magnesium deficiency symptoms.

Drought causes the corn to have a grayish-green color and the leaves roll up nearly to the size of a pencil.

Drought
Drawing: corn leaf showing drought symptoms.

Disease, helminthosporium blight, starts in small spots, gradually spreads across leaf.

Helminthosporium Blight
Drawing: corn leaf showing blight symptoms

Chemicals may sometimes burn tips, edges of leaves and at other contacts. Tissue dies, leaf becomes whitecap.

Chemical Burn
Drawing: corn leaf showing damage from chemical burn.

Symptoms of Root Damage

 

Deep, spreading roots of healthy, high-yielding plant will crowd a half-bushel basket.

Healthy Roots
Drawing: corn plant showing a healthy root system.

Phosphate shortage during early weeks causes a shallow root system with little spread.

Phosphate Shortage
Drawing: roots showing phosphate shortage symptoms.

Rootworms prune heavily as they eat small roots, tunnel in larger ones.

Rootworm Damage
Drawing: corn roots showing rootworm damage.

Poor drainage and hardpan are the causes of a flat, shallow root system. Corn with poor roots can't stand drought and is easily blown over by high winds.

Shallow Root System
Drawing: flat, shallow corn root system.

Acid soil is indicated when the lower part of the root is discolored and decayed, particularly when brace roots shoot from the third or fourth node.

Discolored Roots
Drawing: corn root system damaged from acid soil.

Pruned roots are the work of a cultivator. Shovels were too deep and too close.

Pruned Roots
Drawing: root system damaged from cultivator shovels

Chemical damage makes roots writhe and twist. Joined brace roots are another symptom.

Twisted Roots
Drawing: root system showing symptoms of chemical damage.

Symptoms of Ear Damage

 

A normal ear on well fertilized high-producing corn weighs about two-thirds of a pound. It has well filled tips.

Normal Ears
Drawing: normal ear of corn.

Big ears weighing up to 1 lb. indicate that plant population was too small for most profitable yields.

Large Ears
Drawing: ear of corn that is larger than normal.

Small ears usually are a sign of low fertility. For better yields, boost fertilizer application.

Small Ears
Drawing: ear of corn that is smaller than normal.

Potash shortage shows up in ears with poorly filled tips and loose chaffy kernels.

Potash Shortage
Drawing: ear of corn showing symptoms of potash shortage.

Phosphate shortages interfere with pollination and kernel fill. Ears are small, often twisted and with undeveloped kernels.

Phosphate Shortage
Drawing: ear of corn showing symptoms of phosphate shortage.

Nitrogen is essential throughout the growing season. If plant runs out of nitrogen at critical time, ears are small and protein content is low. Kernels at tip do not fill.

Nitrogen Shortage
Drawing: corn ear showing nitrogen deficiency symptoms.

Green silks at maturity may be caused by too much nitrogen in relation to other elements.

Green Silks
Drawing: corn ear showing green silks at maturity.

Dry weather slows silking behind tasseling; kernels aren't pollinated.

Unpollinated Kernels
Drawing: ear of corn showing unpollinated kernels due to dry weather.

Drawings courtesy of Maynard Reece.
Republished by special permission from The Curtis Publishing Company.

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