Water and Plant height

​Rate of production of new cells produced in the corn apical meristem is largely determined by photosynthetic energy in young plants. These new cells have pliable cell walls at first, that can be stretched by the turgor pressure from water movement into these cells before the epidermal cell walls accumulate the cellulose and lignin to form strong structures. Drought stress during the first 30-40 days after germination results in smaller leaves and shorter plants for the whole season.

Plant size is not always a major contributor to final grain production. Total leaf area per land area exposed to sunlight is essential for maximum grain production per land area. Uneven plant height, allowing some plants to be shaded by adjacent plants is probably more significant to grain production. Uniform water supply within short distances in the field can influence this factor.

Stomata in leaves allows the infusion of carbon dioxide essential for photosynthesis. Corn stomata open when light causes photosynthesis in the chloroplasts of stomata. Stomata also allow the evaporation water from the leaf. This has the effect of allowing the water molecules, adhering to each other, to be drawn from the roots to the above ground corn parts through the vascular system thus providing the turgor pressure for elongation of cells. Water loss through stomata requires a constant source of water

Multiple environment factors influence water supply to corn plants but genetics also distinguish variety reactions to growth of the plant. Root size and growth pattern affect water and mineral uptake. Structure of vascular tissue from roots to leaves affect efficiency of water movement. Number and activity of stomata in leaves affect the evaporation of water from leaves. Efficiency and number of chloroplasts within the cells affect the transmission of light energy to carbohydrates, mitochondrial numbers and efficiency affect the change of this energy into ATP for use in the formation of proteins and other products needed for cell growth. Translation of chromosomal DNA to RNA that moves to ribosomes where the codes for specific amino acids are strung together for specific proteins, some of which are used as enzymes driving production of cell structure components. A large number of those 30-40000 corn genes must be participating in that early growth of a corn plant.

It is not surprising as each year's early season differs, that the ‘best’ hybrid is not the same each year nor in each field.