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Channel Field Check Up
KAYLISSA HALTER
ROBINSON, ILL.
When we encounter less than desirable weather conditions, crops can show or develop nutrient deficiency symptoms. Deficiency symptoms can be caused by a true lack of nutrients, compaction or environmental conditions. Brief deficiency symptoms may occur when the corn plant switches its nutrient uptake from the kernel reserves and seminal roots to its primary source of nutrient uptake through the nodal roots. Nutrient deficiencies can be detrimental to overall crop yield, so it is important to determine whether a true deficiency exists or deficiency symptoms were weather-induced.
Deficiency symptoms usually appear as yellowing, purpling, striping, browning or necrosis of leaf tissues. Overall plant growth and roots can be stunted and deformed. Differentiating where the deficiency symptoms appear on the plant also can be beneficial in diagnosing what nutrient is deficient. Nutrients that are mobile within the plant will show deficiency symptoms on older “lower” leaves, while nutrients immobile within the plant will show deficiency symptoms on the new “upper” leaves. Some of the more common deficiencies are listed below:
Nitrogen (N) deficiency – pale yellow plants, inverted “V” shaped yellowing appearing first on lower leaves and moving upward; favored by lack of N fertilizer, cool and wet soils, N leaching after heavy and excessive rainfall
Phosphorus (P) deficiency – dark purple leaf tips and margins appearing first on lower leaves; favored by saturated or bone dry cold soils, compaction
Potassium (K) deficiency – yellowing and necrosis of leaf margins appearing first on lower leaves; favored by early season root restriction, root pruning, compaction, dry soils
Magnesium (Mg) deficiency – interveinal chlorosis (veins remain green and tissue in-between become pale), round spots develop along with reddish-purple tips and leaf edges; favored by low pH sandy soils and excessive rainfall, high K level induced Mg deficiency
Sulfur (S) deficiency – overall yellowing and stunting, interveinal chlorosis; favored by dry cold soils, low pH sandy soils
If you suspect nutrient deficiency, contact your local Seedsman for help identifying the source of the deficiency and an action plan to bring nutrient levels back up within the plant.
http://www.channel.com/agronomics/Pages/Testing-Corn-Tissue-for-Nutrients.aspx
Sawyer, John. 2004. Nutrient Deficiencies and Application Injuries in Field Crops. Iowa State University Extension. Integrated Pest Management. ∆
KAYLISSA HALTER: Channel Agronomist
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