Control Costs = $14.00 per acre for one application; PL (proportion of yield loss per larva per plant) = amount listed in column 2; MV (market value) = $2.50 per bushel; EY (expected yield) = 140 bushels per acre; PC (proportion of control) = 0.67.
| Loss per larva per plant | |||
| Plant stage* | Proportion | Bu. per acre | Economic injury level** (larvae per plant) |
| 10-leaf*** (mid-whorl) | 0.059 | 8.3 | 1.01 |
| 16-leaf**** (green tassel) | 0.050 | 7.0 | 1.19 |
| Pollen-shedding | 0.040 | 5.6 | 1.49 |
| Blister | 0.031 | 4.3 | 1.93 |
| Dough | 0.024 | 3.4 | 2.49 |
*See description of corn developmental stages.
**Economic injury level =
Control Costs = $14.00 per acre for one application; PL (proportion of yield loss per larva per plant) = amount listed in column 2; MV (market value) = $2.50 per bushel; EY (expected yield) = 140 bushels per acre; PC (proportion of control) = 0.67.
***A leaf is counted when the collar of the leaf is visible; first and second leaves may be dead.
****When the sixteenth leaf collar is visible, the green tassel in most hybrids is showing; first to fourth leaves may be dead.
| These pages adapted from North Central Region Extension Publication NCR 327. To order a printed copy, see our ordering information page. | Last updated October 24, 1996 by John VanDyk http://www.ent.iastate.edu/cornborer/howdamage/table2.html |