Corn seedling vigor

​Speed and consistency of seedling emergence is the first observation of the spring season.  We often use the term vigor to describe this phenomenon.  Hybrids, lots and seed sizes will vary in ‘vigor’ but also environments.  Usually it is not easy to clarify which of these factors were major.  Hybrid vigor can be affected by genetics.  In some cases, it is affected by which of two parent inbreds was used as seed parent because the female parent contributes the mitochondria, and their genetics, to the cells and thus the major source of converting the stored carbohydrates into the metabolic energy needed for cellular division and enlargement.  Total genetics of hybrids also has an effect on growth speed.
 
Seed lots of identical hybrids can vary in seedling vigor. Stresses in seed field when the seed was produced can influence some seed to have poorer germination and early growth.  It could be as simple as rain delaying timely harvest that allows metabolism in the embryo to continue whereas earlier harvest and drying would prevent this process.  Storage at less than optimum temperatures and humidity can also allow aging to occur in some lots.  
 
Field conditions with uneven consistency of soil components and surface debris also will affect uniformity of emergence. Too wet or too dry also varies.
 
Each spring brings its own field stress and challenges. There is no reason to think this year will be different.