Field Observations Thru August 4

Corn

Corn development continues to vary throughout the county.  After tasseling the next growth stage is R1 – Silking.

R1 – Silking.

  • At least 50% of plants in the field will have 1 or more silks emerged. Look at  only the uppermost ear on the corn plant.
  • Pollen grains will land on silks and if receptive,  fertilization will occur.
  • Silks are viable and receptive to pollen for at least 5 days.
  • The plant  uses the most water per day (0.35 inches) during R1, making it very sensitive to stresses.
    • The largest yield reduction occurs with stress at silking
  • Silks have highest water content among all parts of the corn plant.
  • Drought causes silk  elongation to slow down and pollen shed to speed up.
  • Potential kernel number is determined.
  • Maximum plant height is achieved.
  • Potassium uptake is essentially complete and nitrogen and phosphorus uptake is rapid in the plant.
  • Nutrient content by leaf analysis is highly related to the final grain yield at this time.

See all information on all corn reproductive growth stages here.

Soybeans

R3 Beginning Pod

      • A plant can have all of the following:

developing pods,    withering flowers, new open flowers and flower buds

  • Potassium uptake rates peak shortly
    after R2, ranging between 3.5-5.2 lb K2O /acre/day
  • Last growth stage to treat for white mold
  • Scout for insects and diseases.  Spray foliar insecticide or fungicide, if needed.
  • Identify water stress,
    which affects pod formation.

County Rainfall Update

 

 

 

 

 

 

 

Corn Water Requirements

Soybean Water Requirements

 

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