The spring planting season got off to a rapid start in much of the country this spring, but there’s been a very common comment since corn starting emerging - “This corn is yellow, what’s going on?”

Soil conditions and temperatures were great when a large percentage of corn got planted this spring. The weather pattern changed drastically around May 10 and began a prolonged cold and damp period lasting roughly 10  to 14 days in many areas. This resulted in areas where soil temps fell back down to 37 or 40 degrees Fahrenheit. This cold, wet pattern was accompanied by cloudy conditions with very little sunlight.

Nutrient deficiency of nitrogen and/or sulfur is what typically gets the blame for this pale color. While the plants may show nutrient deficiency if you were to take tissue samples, the root cause of their current pale yellow color is the greatly reduced photosynthetic activity of the plant. The cold, wet and cloudy conditions slowed the photosynthesis and root growth of the plants. Reduced photosynthesis caused a pale color of the corn and the slow root growth from the cold spell lead to further yellowing of the corn due to reduced access to plant nutrients by the roots.

Fortunately, the forecast appears to be shaping up in a way that fix this issue in much of the area. Upcoming warmer temps with sunlight will ramp up the photosynthetic factory of the plant and start to improve the color of the corn. This will also speed up the root growth, allowing the roots to take in nutrients and correct the low nutrients levels within the plant. After a few days of these favorable growing conditions, most of the corn should have a much better, healthier color.   

Download a copy of this technical bulletin here: Why Is The Corn So Yellow?    

Sources

1. https://www.canr.msu.edu/news/pale_yellow_and_purple_corn
2. https://www.agvise.com/educational-articles/troubleshooting-yellow-corn/