Water is essential to growth and grain production of corn. It is estimated that current corn hybrids require about 20 gallons of water per plant to produce high grain yields (http://articles.extension.org/pages/14080/corn-water-requirements). Of course, the actual number is variable as affected by weather.
Water is essential for all plants because of its unique molecular structure. Oxygen atom fulfills its need for 2 electrons by sharing an electron from each of two hydrogen atoms. This specific covalent bond with hydrogen is unique in that the single hydrogen atoms are not distributed exactly symmetrically around the oxygen atom, resulting in a water molecule with a slight negative charge on one side of the oxygen component and a slight positive charge around the hydrogen components. This has profound and unique effects on water characteristics essential to plants.
Water molecules are cohesive. They attract other water molecules because each has a slight positive and negative electronic charge. Cohesion of water molecules is essential for the transport of water from the root hairs through the xylem tissue up to stem growing points and leaves. This strong capillary action allows movement water molecules upwards as water evaporates and escapes the plant through the stomata that is replaced by water molecules being pulled upwards.
Water is a universal solvent, again due to its polarity. The negative side of the oxygen atom and the positive side of the hydrogen atoms essentially break apart most ionic compounds. Consequently, it becomes solvent to most mineral sources essential for corn growth. For example, the positive charged potassium ion of potassium chloride is attracted to the oxygen side while the negative side of the chloride ion is attracted to the hydrogen side of the water molecule. This allows the transport of essential minerals for metabolism and structure of the plant.
Oxygen and hydrogen components of water also are essential to the many complex chemical reactions that are within the corn plant cells. Water interacts with the essential storage of energy in carbohydrates during photosynthesis and the release of that energy during respiration.
There are obvious effects on corn when water is deficient but there are also many hidden aspects of the unique water molecules essential to corn growth. An interesting summary of properties of water can be found at https://en.wikipedia.org/wiki/Properties_of_water.
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.