Leaf abnormalities


Leaves shine with a rich dark green colour when adequately fed.

Phosphate shortage

Leaves marked with a reddish-purple colour, particularly on young plants.

Potash deficiency

Appears as a firing or drying along the tips and edges of the lowest leaves.

Nitrogen hunger

Signs of yellowing that starts at the tip and moves along the middle of the leaf.

Magnesium deficiency

Whitish strips along the veins and often a purplish colour on the underside of the lower leaves.


Causes the maize to have a greyish-green colour and the leaves roll up nearly to the size of a pencil.


Helminthosporium blight, starts in small spots and gradually spreads across the leaf.


May sometimes burn the tips, edges of leaves and other contacts. Tissue dies and the leaf becomes whitecap.

Root abnormalities

Deep, spreading roots

A healthy, high-yielding plant will crowd a 20 litre bucket.

Phosphate shortage

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


Prune heavily as they eat small roots and tunnel in large ones.

Poor drainage and hardpan

Causes a flat shallow root system. Maize with poor roots cannot stand drought and is easily blown over by high winds.

Acid soil

Indicated when the lower part of the root is discoloured and decayed, particularly when brace roots shoot from the third or fourth node.

Pruned roots

Result of a cultivator. Shovels wer too deep and too close.

Chemical damage

Makes roots writhe and twist. Joined brace roots are another symptom.

Cob abnormalities

Normal ear

Well-fertilised, high-producing maize cob weighs about 300 grams. It has well-filled tips.

Big ears

Ears weighing up to 450 grams likely indicate that the plant population was too small for most profitable yields.

Small ears

Usually a sign of low fertility. For better yields, boost fertiliser application.

Potash shortage

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

Phosphate shortage

Interferes with pollination and kernel fill. Ears are small, often twisted and with underdeveloped kernels.


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

Green silks at maturity

May be caused by too much nitrogen in relation to other elements.

Dry weather

Slows silking behind tasseling; kernels aren't pollinated.

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