Critical points of influence 150 150 areinheimer

Critical points of influence


9-12 days after emergence a corn plant determines the number of ears it will have.

At 14-21 days it determines the number of rows of kernels per ear.

At 42-45 days it determines the number of kernels per row.

Reduce stress at the critical points of influence.  Growth cycles between vegetative and reproductive dominance.  Critical points of influence occur when the hormone/nutrient balance in the plant shifts from vegetative to reproductive dominance.  Lack of nutritional integrity at these points triggers the breakdown of proteins into peptides and amino acids and creates disease/insect susceptibility.

For apples, pears, cherries, spur bearing trees this occurs at


shoot initiation

bud initiation

fruit fill


spur bud fill

Cobalt inhibits senescence by inhibiting ethylene production which delays maturity and senescence.  The result is uniform maturity.  Apply chelated cobalt at 50g / acre.

The most influential CPIs are:

  1. Reproductive bud determination/initiation (note that for fruit tress this can occur in the previous season, after harvest.)
  2. Bud embryo development
  3. Flowering
  4. Pollination
  5. Fruit cell division (This lasts 10-14 days and determines potential fruit size.  The number of cells is limited by calcium (Ca) availability.  Temperature stress can shorten this window. Seaweeds and cobalt (Co), manganese (Mn) and calcium (Ca) can extend the window.  Tomatoes are about 1/4″ in diameter at the end of this phase.)
  6. Fruit cell expansion (This lasts the remainder of the season and is limited by potassium (K) availability.  Turger pressure determines the firmness of the fruit.)

For this sequence to occur properly there must be adequate amounts of micronutrients including cobalt (Co), manganese (Mn), zinc (Zn), copper (Cu) and boron (B) in addition to the macronutrients.

Optimum moisture is required for flowering, fruit set and new leaf development.  Any deficiency in water at this time will result in a loss of yield.