Seed germination factors are only the beginning of those that eventually effect the performance of the crop. All corn seed is aging, as the physiology involved in digestion of starch in the endosperm allows glucose to be moved to the mitochondria in the embryo cells where it is processed into the ATP needed for production of proteins and specialize structures as the seed grows shoot and root tissue. Each seed within the seed lot is aging at a different rate, resulting in uneven emergence and inter plant competition during the remainder of season.
Soil consistency, water amounts and timing, temperature, crop debris and micro-organisms all interact with the young plant development. Hybrid genetic differences affect the reactions to these variables as well. Vulnerability to aging is mostly inherited through the female parent but genetics of the hybrid influences the reaction to these environmental factors.
Potential pathogens of the corn seedling are also affected by these environmental factors. Cool, wet soils favor Pythium species while slowing the corn metabolism. Anthracnose fungus (Colletotrichum graminicola) and the pathogen Cochliobolus carbonumcausing northern leaf spot are examples of 2 minor pathogens of young emerging corn leaves favored by warm, wet weather. Most virus diseases of corn only become damaging if infected early. This usually is dependent upon an insect vectoring the virus from other grasses. Environmental factors such as presence of adjacent hosts, temperatures and wind are big factors in the virus infection.
Northern temperate zone corn season is beginning now. Interactions of plant and other organism’s biology and physical environments will affect the harvest performance. We will search for a single factor to explain that performance, but it will most likely be complex.
About Corn Journal
The purpose of this blog is to share perspectives of the biology of corn, its seed and diseases in a mix of technical and not so technical terms with all who are interested in this major crop. With more technical references to any of the topics easily available on the web with a search of key words, the blog will rarely cite references but will attempt to be accurate. Comments are welcome but will be screened before publishing. Comments and questions directed to the author by emails are encouraged.