Management Worksheet for First-Generation Corn Borer
 

x

________

% of 100 Plants Infested

________

Average No. Borers/Infested Plant

(determined by checking whorls from 10 plants)

=

________

Borers/Plant

________

Borers/Plant

x

________

% Yield Loss/Borer*

=

________

% Yield Loss

________

% Yield Loss

x

________

Expected Yield (Bu/A)

=

________

Bu/A Loss

________

Bu/A Loss

x

$ _______

Price/Bu

=

$ _______

Loss/A

$ _______

Loss/A

x

________

% Control (80% for granules; 50% for sprays)

=

$ _______

Preventable Loss/A

$ _______

Preventable Loss/Acre

-

$ _______

Cost of Control/A

=

$ _______

Gain (+) or Loss(-) per acre if treatment is applied

 *5% for corn in the early whorl stage; 4% (late whorl); 6% (pretassel).

Management Worksheet for Second-Generation Corn Borer
 

________

Number of Egg Masses/Plant

(cumulative counts, taken 7 days apart)

x

    4 Borers/Egg Mass*

=

________

Borers/Plant

________

Borers/Plant

x

________

% Yield Loss/Borer**

=

________

% Yield Loss

________

% Yield Loss

x

________

Expected Yield

=

________

Bu/A Loss

________

Bu/A Loss

x

$ _______

Price/Bu

=

$ _______

Loss/A

$ _______

Loss/A

x

      75% Control

=

$ _______

Preventable Loss/A

$ _______

Preventable Loss/Acre

-

$ _______

Cost of Control/A =

=

$ _______

Gain (+) or Loss(-) per acre if treatment is applied

 *Assumes survival rate of 20 percent (4 borers/egg mass).

 **5% for corn in the early whorl stage; 4% (late whorl); 6% (pretassel); 4% (pollen shedding; 3% (kernels initiated).  Use 3% per borer per plant if infestation occurs after silks are brown.  The potential economic benefits of treatment decline rapidly if infestations occur after corn reaches the blister stage.