A few cases of purple corn have been reported this week. This phenomenon occurs when there is a combination of hot, sunny days followed by cooler nights, as we have seen in parts of Quebec and elsewhere for a few days now. The recent heat and sun have stimulated photosynthesis in corn, resulting in increased sugar production in the plant. At the same time, the cooler nights slowed down the corn's metabolism and the accumulated sugars oxidized to red (anthocyanin).

This phenomenon is visible when the corn is between stages V3 to V6. During this time, the corn is in transition at the level of the root system. The roots are poorly developed and have difficulty metabolizing the sugars produced by photosynthesis, which accumulate in the leaves, masking the green pigmentation of the chlorophyll.

It should be noted that some hybrids demonstrate this phenomenon more than others. This temporary coloring has no impact on corn yield. The purple color should disappear when the good weather returns.