By Dave Nanda, Director of Genetics and Technology for Seed Consultants, Inc.
Many corn fields look purple during the seedling stage? The reasons for the young seedlings to turn purple are as follows:
• Purple leaves are caused by a pigment called anthocyanin. When the sugars produced by the chlorophyll cannot be deposited in roots, stalks and new leaves, sugars are converted to anthocyanin which is red to purple in color.
• Acidic soils with pH lower than 5.5 may cause seedlings purpling. Wet soils can inhibit the nutrient uptake.
• Purpling generally occurs between V2 to V5 stage of growth. By V8, purple leaf syndrome disappears and the color becomes healthy green.
• Any plant stresses which reduce the uptake of phosphorus may result in purple leaves. Root restrictions may cause phosphate deficiency.
• Early planting can cause stress and lead to purpling due to cool nights and warmer days. Sunny and warmer temperatures help in development of green color.
• Cultivate carefully and avoid root pruning.
• Compacted layers make it difficult for the small roots to penetrate and absorb nutrients.
• Herbicide and insect injury can cause stress and purple leaves.
• If most plants have purple stalks and leaves in a field, it might be caused by hybrid genetics.
• Purple color does not cause slower growth. It is caused by cooler temperatures.
• Purple color in seedlings does not generally affect yield.