Corn Pollination Trivia

Pollination success is critical for determining final yield.  The number of kernels set is determined at pollination time.  Because our conditions are ideal this year, with lots of sun, adequate soil moisture and excellent plant health, we are going to see tremendous kernel set.  Drought is the single greatest environmental factor that interferes with the pollination process. 

Pollination

• Pollen shed is controlled by a combination of genetic and environmental factors.
• Once pollen grains have matured inside the tassel anthers, the anthers begin to dry.
• Anthers come in a range of colours, from dark purple to light yellow.
• Anthers typically shed pollen around mid-morning when anthers dry in the heat and sun.  

• As the anthers dry they will split apart to allow pollen grains to fall out.
• When pollen makes contact with a receptive silk the pollen grain grows through the silk channel.
• Pollen grains are viable for only a few minutes after they are shed.  They quickly dry out and die.
• A tassel normally sheds pollen for about 5 days.
• A tassel will not shed pollen when it is raining.

Silk Emergence

• Silks come in two main colours, pink like the ones above (Cathy's favourite) and yellow.
• Each silk that emerges connects to a single ovule or potential kernel.
• A silk must be pollinated for the ovule to develop into a kernel.

• Silk emergence starts with the base and proceeds to the tip of the ear.  This year it is taking about 6 days for silks to complete emergence.
• Silks continue to lengthen for up to 10 days.
• Silks become less receptive to pollen over time.

• This picture shows silks that are fertilized.  They will stop growing and begin to dry up.

• When the ovule is fertilized, the silks detach and fall away.  This picture shows a fully fertilized ear.