Foliar Symptoms of Corn Nutrient Deficiencies

Foliar Symptoms of Corn Nutrient Deficiencies

Early season corn scouting to identify any foliar nutrient deficiency symptoms can be helpful to determine if corrective options are available. There can be other conditions that make nutrient deficiency symptoms more severe or mimic nutrient deficiencies. These conditions include environmental interactions, herbicide injury, insect feeding, nematodes, compaction, root pruning, product genetics, and other factors. Soil and tissue testing can help determine if a true nutrient deficiency exists. Springtime deficiency symptoms often disappear when the soil becomes warmer and drier and after the plant has developed a larger root system.

Five General Types of Nutrient Deficiency Symptoms in Corn:

• Chlorosis - yellowing due to reduction in chlorophyll – Uniform or interveinal (striped)
• Necrosis - death of plant tissue
• Lack of new growth or terminal growth
• Anthocyanin accumulation (when metabolic processes are disrupted) resulting in reddish (or purple) color
• Stunting with either normal, dark green, or yellowish coloration.¹

How Nutrient Mobility in the Corn Plant can Influence Deficiency Symptoms

Nutrients that are mobile within the plant can be translocated from older to newer leaves to help maintain the new growth. Deficiency symptoms of these nutrients appear in older corn leaves first. These nutrients are:

• Nitrogen (N)
• Phosphorus (P)
• Potassium (K)
• Magnesium (Mg)
• Chlorine (Cl)

Immobile or non-translocated nutrients typically show deficiency symptoms in the newest corn leaves. These nutrients are:

• Zinc (Zn)
• Sulfur (S)
• Calcium (Ca)
• Boron (B)
• Iron (Fe)
• Manganese (Mn)
• Copper (Cu)
• Molybdenum (Mo)
• Nickel (Ni)

Identifying Corn Nutrient Deficiency Symptoms

Nitrogen (N) Deficiency in Corn:

Young corn plants that are N deficient appear spindly, stunted, and light green in color. Because N is mobile within a corn plant, a deficiency shows up first on the oldest (lower) leaves which turn pale or yellowish green (Figure 1) and later in the season the leaf can develop an inverted “V” or spear shaped discoloration starting at the tip of the leaf and extending toward the leaf base (Figure 2). The lower leaves start to “fire,” turning yellow and eventually die completely. The deficiency symptoms can work their way up the plant from older leaves to newer leaves. Ears are likely to be small and pinched at the tip.^1,2

Phosphorus (P) Deficiency in Corn:

Phosphorus deficient corn plants often appear stunted, slowly growing, and dark green or bluish green. The stem and lower leaves become purplish at the tips and leaf margins and in more severe cases, the entire leaf can become purple. Since this nutrient is immobile in the soil, and the uptake of P by the plant is highly dependent on diffusion from the soil to root surfaces, any soil condition that limits root growth, such as cool temperature, wet or very dry conditions or compaction, can induce deficiency symptoms even with adequate P levels in the soil. (Figure 3).^1,2

Potassium (K) Deficiency in Corn:

Potassium deficiency symptoms usually don’t appear until the corn plant is about two feet tall. Since K is mobile within the plant, the older, lower leaves of K deficient plants exhibit edges that can become yellow (Figure 4) and eventually turn brown and necrotic, leaving a “scorched” appearance (Figure 5). The interior of the leaves remains green with yellow striping. Lodged stalks and small ears are often the result of K deficiency.^1,2

Sulfur (S) Deficiency in Corn:

Sulfur deficient plants in the early vegetative growth stages can be identified by the youngest leaves showing a yellow striping, particularly at the leaf margin (Figure 6) or light-colored leaves emerging from the whorl (Figure 7). This is because S is not easily translocated within the plant. Sulfur deficiency is often confused with an N deficiency during early plant development; however, it is the lower leaves (older leaves) that turn yellow when there is an N deficiency. Sulfur deficiency seldom appears on mature plants. Cold wet soil, low soil pH, or low organic matter can favor the development of S deficiency symptoms.^1,2,3

Zinc (Zn) Deficiency in Corn:

Zinc deficiency can be observed as wide bands starting at the base of the leaf and extending toward the tip of the newer leaves (Figure 8) or as interveinal chlorosis which is light green to white stripes between the veins extending to about three-fourths the length of the leaf blade (Figure 9). In cases of severe Zn deficiency, new leaves can be almost white. The internodes of the corn plant may be shortened and overall growth stunted. Soil conditions that favor a zinc deficiency include high soil phosphorus content, high soil pH, and cool wet soil. Areas of a field where topsoil was removed because of land leveling or erosion may also display Zn deficiency symptoms.^1,2

Magnesium (Mg) Deficiency in Corn:

Magnesium deficiency initially appears as yellow or white streaking between the leaf veins because of a chlorophyll shortage. Severe deficiencies result in leaves developing full length striping with green veins and yellow tissue between the veins. The leaves eventually become reddish purple (Figure 10), and the edge and tip die if the deficiency is severe. Lower leaves develop striping first. Magnesium deficiency is favored by low soil pH and coarse textured soil.^1,2

Iron (Fe) Deficiency in Corn:

Interveinal chlorosis is the primary symptom of Fe deficiency. The leaf veins remain green while the tissue between the veins turns yellow (Figure 11). It is usually associated with a soil pH of 7.5 or higher along with a high lime (calcium carbonate) concentration. Keep in mind that iron chlorosis symptoms are not necessarily due to the lack of iron in the soil, but rather the Fe that is taken up by the plant is not in a useable form. Leaf tissue analysis often reveals adequate iron in the plant despite the deficiency symptoms being present.¹

Soil Conditions that may Impact Corn Nutrient Availability

Soil pH:

Both low and high soil pH can cause a reduction in nutrient availability to the corn plant, depending on the nutrient. The optimum pH for corn ranges from 5.8 to 6.2 (Figure 12).

Soil Compaction:

Soil compaction can restrict root development that can cause foliar symptoms that mimic nutrient deficiency, such as phosphorus for example (Figure 13).

Injury to roots:

Injury to roots by insects, nematodes, diseases, fertilizer burn, or chemicals can look like a nutrient deficiency (Figure 14).

Other Possible Causes of Corn Nutrient Deficiency Symptoms

• Reduction in plant metabolism and photosynthesis from cool nights, cloudy weather, and saturated soils.
• Warm temperatures after a cool period can cause plants to grow rapidly and may induce temporary deficiencies.
• Slow nutrient release from residue.
• Soil attributes can cause deficiencies – consider texture, CEC, OM, pH, etc.
• Nutrient interactions – the excessive availability of one nutrient can induce a deficiency of another nutrient, for example, high soil phosphorus levels can induce a deficiency of zinc.

The Potential Impact to Corn Yield from Nutrient Deficiencies

The effect of potential yield loss from nutrient deficiencies is first dependent on the severity of the nutrient deficiency but is also dependent on how quickly, if possible, the deficiencies are rectified by more favorable environmental conditions and/or the application of additional nutrients. Season long deficiencies can result in substantial yield loss. As an example, for each day that sulfur is deficient past the first 21 days after emergence there is a potential loss of one to two bushels per acre per day to the point that total crop failure could be experienced.³ When roots are injured by insects or chemicals and depending on the severity of damage and the time required for new root growth, the potential for yield loss increases.

Managing Corn Nutrient Deficiencies

A nutrient deficiency diagnosis based on deficiency symptoms alone is much less dependable than a diagnosis that is supported by samples that have been analyzed by a reputable lab. Soil and crop tissue testing can be used to help determine if a deficiency exists and if it is due to soil nutrient availability, restricted plant uptake, or reduced metabolism. When plants are sampled for suspected nutrient deficiency tissue testing, a sample of healthy, normal looking plants should also be collected and analyzed to help determine if a nutrient deficiency is the cause. In-season plant tissue testing can be useful in diagnosing nutrient deficiencies in field crops, but it must be used with caution. It is very important to follow the tissue sampling procedures recommended by the lab doing the tissue analysis as these procedures can vary by lab. In general, when corn is in the early vegetative growth stages up to V5 to V6 the entire aboveground plant should be collected for testing. In later vegetative growth stages through the VT (tassel) to R1 growth stage (silking) the blade of the leaf opposite and below the primary ear should be sampled.⁴ Any time after the VT to R1 growth stages, test the ear leaf. A tissue test, in combination with a soil test, may provide answers as to why plant nutrient levels are high or low. Alone, soil test results can be the most useful for predicting nutrient needs for the following growing season but may not give reliable results for nitrogen or sulfur levels due to potential leaching of these nutrients. Corn responds best when the soil pH level is near neutral, or around the 6.8 level. Appropriate amounts of lime can increase soil pH and help increase the availability of some plant nutrients on acidic soils.

Nutrient deficiencies are often outgrown when soils become warmer and drier because of root growth, microbial activity, and the breakdown of organic material can enhance the release of nutrients. Unrestricted root growth can allow roots to reach water-soluble nutrients such as nitrogen and sulfur that may have moved deeper (leached) into the soil profile. Between the V3 to V5 growth stages, while corn plants transition from seed dependency to acquiring energy from photosynthesis, plant appearance can be variable which can be caused by environmental conditions. During the vegetative stages, a wait-and-see approach can generally be taken, and tissue samples gathered just prior to silking if symptoms persist. Correcting the problem may not be feasible for the current crop year; however, soil preparation for the next season can include fertilizer applications and lime applications (to adjust pH in acidic soils) based on soil test recommendations, and compaction alleviation or prevention to correct potential nutrient deficiency problems in the crop next year.

Sources

¹Nafchi, A. M. 2023. Monitoring corn nutrient deficiencies: The traditional and precision ag approach. South Dakota State University Extension. https://extension.sdstate.edu/monitoring-corn-nutrient-deficiencies-traditional-and-precision-ag-approach
²Stevens, G., Motavalli, P., Scharf, P., Nathan, M., and Dunn, D. 2002. Integrated pest management: Crop nutrient deficiencies & toxicities. IPM1016. MU Extension. University of Missouri-Columbia. https://extension.missouri.edu/media/wysiwyg/Extensiondata/Pub/pdf/agguides/pests/ipm1016.pdf.
³Heiniger, R., Crozier, C., Hardy, D., Walls, B., and Reich, R. Updated 2025. Sulfur deficiency symptoms in emerging corn. NC State Extension. North Carolina State University. https://corn.ces.ncsu.edu/sulfur-deficiency-symptoms-in-emerging-corn/.
⁴Mallarino, A. and Sawyer, J. 2019. Tissue testing for field Crops requires cautious use and interpretation. Integrated Crop Management. Iowa State Extension and Outreach. Iowa State University. https://crops.extension.iastate.edu/cropnews/2019/06/tissue-testing-field-crops-requires-cautious-use-and-interpretation
Web sources verified 07/03/2026. 1213_134271