Corn Diagnostic Guide - Emergence to 8-10 Leaves
|
Appearance |
Symptoms |
Possible Cause(s) |
|---|---|---|
| Scattered dead or poorly growing plants | Uneven growth (see Uneven Corn) |
|
| Slow growth |
| |
| Plants stunted, wilted and/or discolored |
| |
| Plants cut off above or below ground level or rapid wilting | ||
| Sudden death of plants |
| |
| Wilting | Upper leaves roll and appear dull or sometimes purple; stunting of plants; plants may die |
|
| Whorl dead | ||
| Crown roots not developing |
| |
| Discolored Plants | Pale green color |
|
| Yellow or dying leaf edges | ||
| Yellowing of upper leaves |
| |
| Yellowing of lower leaves |
| |
| Purpling or reddening of leaves from tip backward |
| |
| Whitish or yellow striping between leaf veins |
| |
| Whitish striping along leaf veins |
| |
| White areas in the center and towards base of leaves | ||
| Lower leaves dead, tips dying on upper leaves |
| |
| Leaves appear sandblasted; pale green or whitish in color |
| |
| Yellowing or browing beginning from leaf tips |
| |
| Leaves turn white to tan and die |
| |
| Light and dark mottling or mosaic on leaves |
| |
| Yellow to white strips with smooth margins running length of leaves |
| |
| Bleached bands across leaf blades; leaf tips may die back; leaf collapse and fold downward |
| |
| Discolored and stunted plants | Yellow leaves; spindly, stunted plants |
|
| Purple or red discoloration of leaves, especially leaf margins; stunting; stubby, malformed roots; drouthy appearance |
| |
| Discolored, stunted and/or malformed | Tillering, stunting |
|
| Yellow-green tint; severely stunted; inability of leaves to emerge or unfold |
| |
| Leaves yellow and not expanded; roots sheared off or dried up |
| |
| Yellow strips in leaves, stunting |
| |
| Leaves fail to unfurl properly, often underground; plants may be lodged, lying flat on ground |
| |
| Leaves stunted and twisted and may appear knotted |
| |
| Shoots and roots malformed; onion-leafing (leaves remain wrapped) | ||
| Plants bent or twisted; stunted; irregular row of holes in unfolded leaves | ||
| Lesions on leaves | Spots of dead tissue on leaves |
|
| Oval, circular or rectangular lesions on leaves |
| |
| Long, irregular yellow to brown streaks in leaves | ||
| Tan, spindle-shape lesions with parallel sides and buff to brown borders |
| |
| Oblong, oval, tan colored spots with yellowing of leaves |
| |
| Brown, oval lesions; yellow to reddish-brown | ||
| Small transluscent, circular to oval lesions | ||
| Circular to oval cinnamon-brown pustules | ||
| Plant tissue missing or removed | Plant cut off at ground level |
|
| Leaves eaten off or large areas of leaf tissue removed | ||
| Ragged leaves shredded or torn |
| |
| Rows of circular to elliptical holes across leaves (shothole affect) | ||
| Ragged holes in leaves |
| |
| Longitudinal slits chewed out from between leaf veins |
| |
| Irregular brown lines or tracks scratched from the top layer of leaf tissue | ||
| "Window effect" of leaves - interior leaves eaten out |
| |
| Yellow, weakened area on leaf mid-rib from tunneling feeding damage |
Planting to Emergence || Emergence to 8-10 Leaves || 8-10 Leaves to Tasseling || Tasseling to Maturity || Corn Diagnostic Guide
Adapted by James H. Hill, Iowa State University - Hancock County Extension Education Director, from information prepared by Dale M. Studt, retired ISU Extension Crop Production Specialist.
