Purple coloration in corn. – a result of the expression of genes for anthocyanin pigment formation.
Photo by Ignacio Ciampitti, K-State Research and Extension.
By Louis Sutton
AgVenture Regional Product Manager
As I have been out looking recently, I have seen some purpling of corn plants in the fields. Did you know some of this is natural and can be good? Some hybrids have a normal purpling to the leaves due to genetics, and as researchers, we take notes on this. We feel it is a good trait to see as some of the better hybrids genetically do this and the purpling disappears quickly with no damage to the plants.
A close-up look with a microscope reveals that the pigment is only present on the top layer of the leaf tissues, without affecting the chlorophyll. Photo by Ignacio Ciampitti, K-State Research and Extension.
But, what I have been seeing is not from this genetic trait. That is a bit of reason for concern, ultimately depending on how long the purpling lasts and the extent of purpling. Purple leaves are caused by a pigment called anthocyanin. This happens when sugars produced by the chlorophyll cannot be deposited in the growing stalks, leaves, and roots; we typically see this with wet, cold weather. Other causes can be phosphate deficiency, compaction, misapplied pesticides and herbicides. In some cases, correctly applied pesticides and herbicides can cause this too, as well as root injury and uneven planting depth that we talk about in our Maximum Profit System™ approach. Some of these issues can be taken care of in the fall with tillage while others are best handled by being aggressive, as well as understanding and following the labels for applying pesticides and herbicides.
However, the purpling corn that I’m seeing should go away when it warms up and the roots and stalks start growing at a normal pace. Be watchful if this has been going on for a longer period on your operation, as the sugars can damage the plants because they basically turn into an acid that can kill the plants.
Purple coloration in corn at diverse growth stages — a result of the expression of genes for anthocyanin pigment formation.
Photo by Ignacio Ciampitti, K-State Research and Extension.
If you see that you have purple corn, record it in your field’s data. This will remind you to monitor this field in case you need to replant it – which is unlikely, but could happen. Also, make sure you watch for other diseases or insects as they could be a issue in this stressed corn. Plus, knowing that your corn experienced early season stress and purpling will allow you to schedule your harvest timing just in case any of the negative issues do come up before harvest, as all stressed corn can have issues.
Remember to walk your fields, take notes, and never give up on your crop. Your AgVenture Yield Specialist and the AgVenture product team is here to support you from planning to planting to harvest and every day in between.